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B+W 25.5 Digital PRO UV/IR (486)

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1. lt CD 5 0X0tb W EE W 600 60060000O000O0O00000O0OO SLIM and oversized wide angle filters Explanation of Symbols Q Standard mount see pages 62 and 63 Q SLIM wide angle mount Oversized wide angle mount WIDE ANGLE FILTERS Unmounted glass filter squares see pages 62 and 63 3 3 3 3 3 3 3 2g olol x Single layer coating multi layer coating x x x x Single layer and MRC multi layer coatings are available d 2 2 2 2 2 22 22 2 2 22 9 UV Blocking Filter UV 010 0909009000000 0 00 0000 Skylight Filter KR 1 5 TH 90 00 0000 000000 000 11 Neutral Density Filters 101 102 0909000000000 0 0000 000000000209 Neutral Density Filter 103 0000 Neutral Density Filters 106 110 113 120 0 15 Polarizing Filter according to Kasemann linear ocog 2020029 Polarizing Filter according to circular OIOIOIOO 0000000700 Circular Polarizing Filter
2. e 4 ww E E E B i m u m m m es ij Our Range of Products Some products may not be available in your country d E LM EE ND L L E T E 44 Ff DE EE kh RN E m N E 4 EN isa m ENT ee 68 7 2 en E t 11 LE FI NH EMI JJ oc FF M IN NM ANIM EN NI EIN Filters The leading brand for demanding professionals and amateur pho tographers for creative imaging with optimal quality Choose from correction and effect filters for color and black and white photog raphy Kasemann polarizing filters close up lenses special effect and trick lenses filters with SLIM mounts for vignetting free exposures with wide angle zoom and fixed focal length lenses
3. 4 a a a Coatings At first glance the coating of filters may not seem particularly important because unlike photographic lenses they have only two glass air surfaces that can lead to reflections that reduce the transmission of light This also applies to B W Polarizing Filters be cause their polarizing foils are cemented between two glass discs The coating of the front surface seems even less important because the first reflection is directed away from the lens In other words it cannot gener ate stray light or ghost images Does coating even have any relevance at all considering the fact that the transmission loss for both uncoated surfaces together amounts to only 8 or 1 9 of an aperture stop Closer examination shows that high grade coating does indeed enhance image quality signifi cantly especially with high contrast subjects and when a light source like the sun or a light bulb is visible in the picture Once again with normal single layer coatings the loss of transmission for both surfaces on average amounts to only approximately 3 whereas with more complex multiple coatings MC it amounts to a mere 0 5 A more significant aspect than the gain in light transmission is the reduction of reflections and ghost images to about 1 3 with simple coatings and to less than 1 16 with MC coatings Coating is even more important when two filters are used in
4. L M i VE d j LB EIGHT BALANCING Cor seu FILTERS COLOR CORRE Jm 7 il 1 i i ut Hi T TU n S TI m M a iil ei 1 WM 1 AN u F N nature and light bulbs often vary so that LB or i conversion filters LB Light Balancing become nece ary for neutral color rendition m M the color of the light source to the color balance of 7 CC z Color Correction or Color Compensatir The color of daylight varies from morning to noon and to evening It also does so differently in winter with an overcast sky or in the fog Color differences are even more pronounced between various sources ION FI of artificial light Arc lights appear to us as bluish white halogen bulbs yellowish normal tungsten bulbs even more yellowish candlelight warm or ange But our perception adapts to changed colors after only a short time so that after a few minutes we perceive practically any light as white again But colo
5. Photo Optics Absolutely state of the art taking and enlarging lenses for all fields of application of professional analog and digital photography from 35 mm to large format Machine Vision Specialty lenses corrected for the infrared range high resolution C mount lenses and macro systems for image processing and for non contact measurement technology as well as customer speci fied design and fabrication of optical and mechanical components Cine Projection High performance motion picture projection lenses for 16 mm 35 mm and 70 mm films anamorphic projection attachments wide angle projection lenses for 70 mm films with 8 or 10 perfo rations per frame test films for 35 mm projection Digital Projection New Cine Digital line of projection lenses in a large variety of closely stepped fixed focal lengths for digital high performance projectors and anamorphic attachments with guaranteed high contrast and sharp detail rendition Their fields of application range from digital cinemas to fixed installations in front and rear projection all the way to rental and staging applications Ophthalmic Optics Glass and plastic lenses for eyeglasses single and multiple strength lenses gradient lenses of high refractive materials with special glass geometry for better appearance and greater wearing comfort Servo Hydraulics Electro hydraulic and electro pneumatic servo valves with high g
6. lt 20 5 20 0 Ml ETE 0 re TET 300 nm 400 nm 500 nm 600 nm 700 nm 300 400 500 600 700 ND Filters 101 102 103 106 110 113 120 Page 11 Conversion Filters 1 5 3 6 12 81 81B Page 21 i a LL Es A NN We 20 mni NM 5 0L 300 400 500 600 700 CC Filters Cyan blue green 05 10 20 40 Page 23 100 80 60 JN Transmission 76 Transmission 76 N 300 400 500 600 700 300 400 500 600 700 Redhancer 491 Page 15 Filters Magenta purple 05 10 20 40 Page 23 100 100 80 80 60 60 A Pure transmission Transmission N 300 400 500 600 700 300 400 500 600 700 TRANSMISSION CURVES thermal radiator like the sun or halogen or incan transmission curve shows would transmit pure yel descent bulbs but has a discontinuous spectrum low around 580 nm wavelength without affecting with an irregular spectral intensity distribution or it but it would change a mixture of green around when a color is not pure but mixed with other color 510 nm and red around 640 nm to orange because components Yellow Filter 022 for example
7. FILTER HANDBOOK Computer controlled manufacturing processes safeguard the high level of B W quality Only the best optically homogeneous optical B W employs cutting edge vacuum coating equipment for coating its filters glasses are used B W filters Quality filters from B W Tradition amp Innovation in Germany Strict controls at all stages of production from design to the final checkout ensure full performance for optimal imaging quality The B W filter manufacturing company was found ed in Berlin in 1947 by business partners Biermann and Weber In 1985 the merger with the Jos Schnei der Optical Works in Bad Kreuznach expanded the B W line of products with optical filters for science and technology It also generated significant progress in multi layer coating systems MC As a result B W became the first manufacturer of filters in the world to offer the innovative water and dirt repel ling MRC multi layer coating process which in addi tion to its reflection preventing qualities is also re garded as being especially scratch resistant Filters solve a great variety of tasks in photography They match the illumination to the type of color film they enhance contrast and colors they attenu ate the amount of incoming light they can make the structures invisible to our eyes visible to the film and they offer numerous optical effects for creative composition or for abstractio
8. B W FOR FILM amp DIGITAL Correction and creative filters with a great variety of accessories for analog and digital photography Filters are indispensable for serious photography They can tailor the color temperature of the light to the type of film to correct color casts increase color saturation and penetrate veils of haze block sharp ness reducing as well as color shifting ultraviolet and infrared radiation control the rendition of colors in terms of shades of gray on black and white films reduce or increase contrast eliminate or attenuate unwanted reflections or even enhance them if needed and much more as described on the pages that follow Dioptric lenses for close up shots down to the range of macro photography a great variety of trick and special effects attachments rigid and folding lens hoods protective covers adapter rings special mounts for individual applications filter cases and micro fiber cleaning cloths complement the line of B W filters The range of applications of B W filters and ac cessories includes all analog and digital photography rangefinder and single lens reflex cameras digital cameras camcorders and broadcast video and cin ematography B W uses the very best glass and filter mounts and machines them with CNC controlled fabrication machines to make sure that filters supplementary lenses and special effects attachments perform their functions optimally without jeopardizing
9. the optical and mechanical design of the lens nodal point separation and distance of the close up lens from the subject side nodal point Thus the repro duction ratio indications can only be used as guidelines The exact reproduction ratios must be determined individually for every lens The frame filling subject size can be calculated by multiplying the film format by the reciprocal of the reproduction ratio example the standard 24x36 mm format on 35 mm film with a reproduction ratio of 1 4 Closest focusing distance with a 50 mm lens will cover a subject size of 96x144 mm Frame filling image with an attached B W Close Up Lens NL I A little larger still with B W Close Up Lens NL 2 this size can also be attained with NL 2 close up lens when focused at the closest distance Approaching the macro range with B L Close Up Lens NL 3 A true macro photograph with the Macro Lens B W p Lens NL 1 With 1 diopter it is ideal for telephoto and zoom lenses with a near focusing distance of approximately 1m 31 4 feet resulting in a focusing range without gap With the 35 mm format it is ideal for lenses with focal lengths between 85 mm up to approxi mately 1 5 and 200 mm up to approximately 1 3 50 lens start with the NL 2 close up lens B W Te Lens NL 2 The 2 diopters of this close up lens focus at a dis tance of 0 5 15 feet with the lens focused at infinity
10. T an environmentally safe manner Available in two sizes each with a protective plastic envelope appr 36x29 cm 14 113 in and 17x17 6 2x6 2 in B W Plastic Filter Case BH D and E Thanks to their transparent lids these handy flat fil ter cases made of impact resistant plastic material let you see right away which filter is stored inside A foam rubber insert keeps filters from rattling A filter contained in such a case can be carried in a pocket _ without any problems These B W filter cases are available for the following filter thread sizes Size For filters and and special effects a attachments up to 52E Matching step down inserts up to 48E Size D For filters up to 82 E Matching step down inserts up to 62E Size E For filters up to 105 E B W Plastic Case for Four Filters The material and features of this filter case are the same as those of the cases described above except that it has an insert that holds four filters Recesses in that insert keep the filters from touching or rub bing against each other Finger indentations permit the easy removal of filters from their recesses The four filter case is available with a choice of an insert for filter sizes 49 E 52 E 55 E or 58 E B W Filter Pouch B 6 This folding padded filter pouch is made of a flexible plastic material with snap fasteners Its see through pockets shelter six filters or close up lenses in sizes u
11. of a basic outfit The filter factor is 4x B W Neutral Density Filter 103 Somewhat more difficult to manufacture and thus a little costlier this Neutral Density Filter re duces the light intensity by three f stops log density 0 9 It still features very good color neutrality This ND filter is especially appropriate for use on video cameras when the lens cannot be stopped down suf ficiently in great brightness or when a deliberately low depth of field is desired The filter factor is 8x B W Neutral Density Filter 106 This Neutral Density Filter reduces the light six f stops With this filter and without changing the f stop a shutter speed of 1 60 s is changed to a full second thus requiring the use of a tripod Flowing water is rendered as flowing in the photo and people moving in streets are dissolved in unsharpness or become invisible Because of its higher transmission in the red beyond 660 nm this filter brings a slightly warm tone to color photographs If this effect is un desirable a UV IR Blocking Filter 486 in front of the neutral density filter not behind it remedies that situation The filter factor is 64x B W Neutral Density Filter 110 With a light intensity reduction of ten f stops this B W Neutral Density Filter has a slightly stronger warm tone than the ND 106 Its principal field of ap plication is the observation and documentation of industrial pro
12. For the normal lens it is a stepless extension of its close up range up to approximately 1 4 5 On short to medium telephoto lenses it extends the close up range seamlessly with an 85 mm lens to appr 1 3 5 and with a 135 mm lens to appr 1 2 5 B W Close Up Lens NL 3 With its 3 diopters the near focusing distance of this close up lens begins at 33 cm 13 inches from the front rim regardless of the focal length of the main lens When close ups have to be taken because of the wide angle effect of a 35 mm lens the NL 3 close up lens is ideal for a seamless extension of the normal close up range up to approximately 1 5 5 B W Close Up Lens NL 4 The 4 diopters of this close up lens are the right power for closer focusing with a 50 mm lens up to approximately 1 3 when you have reached the limit with the NL 2 lens With 85 mm up to appr 1 2 1 and 100 mm up to appr 1 1 9 telephoto lenses it is the highest power and it should be used with the main lens stopped down to at least 8 B W Lens NL 5 With 5 diopters the NL 5 serves for the seamless extension of the range provided by the NL 3 close up lens on a 35 mm main lens up to appr 1 3 5 If you can tolerate a small gap after the NL 2 close up lens on a 50 mm main lens appr 1 4 4 to 1 4 then you enter a little further into the macro range with the NL 5 instead of the NL 4 up to appr 1 2 6 B W Macro Lens suitable for digital photogr
13. TEM 5 1 i 7 2 ros Tu Lan 5 6 a ln T i da 5 jig P Acht y e Ls Fe M AIT dur ee 4 min ib PIDE ee Fe T 25 P 3 Fs Gam E LEO r fm t ur ol i I T x I 1 an da HL uoi 5 Tm i i Lu MERE T p dere Re exon ife ic eR Mrs LN a M gin Pi io Tur L mus i EL Pe Mam Jo Lir d E Th I Black and white photograph taken without a filter the original colors are shown in the color photographs on page 20 With yellow filter 023 the yellow facade is brightened but the sky could do with a little more darkening With orange filter 041 the facade remains bright but the clouds are rendered more prominently Light Yellow Filter 021 2 E 66455 This filter suppresses violet and attenuates blue the other hand green yellow orange and red are reproduced in lighter shades It is ideal for landscape photographs since white clouds will contrast more against the darker blue sky and the shades of green on plants are more differentiated Freckles and skin blemishes in portraits can be attenuated tans can be rendered lighter Its filter factor is approximately 1 5
14. combination Not only will the losses in transmission and the reflections be doubled with such combina tions but also multiple reflections are possible be tween the filters which may cause disturbing double images when there are light sources included in the image area Single coatings reduce the occurrence of double images to approximately 1 8 whereas MC coatings reduce it to approximately 1 70 MRC coating Multi Resistant Coating by B W is not only an extraordinarily effective multiple layer coating it is also harder than glass so that it protects filters from scratches for instance when cleaning the filters and it is also water and dirt repellent thus facilitating filter maintenance The diagram that follows shows the combined amount of reflection of the two surfaces in the visi ble range of the spectrum for uncoated surfaces for surfaces with a single layer coating and for surfaces with MRC multi layer coatings All B W color filters for color and black and white photography as well as the neutral density filters 101 102 and 103 normally have single layer coatings and Reflection p for 2 surfaces with n 1 52 uncoated 7 1 1 y LA TM mem RR RR 300 nm 400 nm 500 nm 600 nm 700 nm IN most of these filters are also available with MRC multi layer coatings B W polarizing filters have dif ferent coatings depending on the kind and on the glass
15. 400 500 600 700 Explanation of Symbols Q Standard mount for thicker filters prisms close up lenses Q Standard mount F Pro SLIM wide angle mount see page 64 Oversized wide angle mount see page 64 Unmounted glass filter squares Single layer coating MRC multi layer coating Single layer MRC multi layer coatings are available UV Blocking Filter UV 010 Skylight Filter KR 1 5 Standard filters Lens hoods Neutral Density Filter 101 102 Neutral Density Filter 103 Neutral Density Filter 106 110 113 120 OO M19 0x0 5 M255x05 GENE M27 0x0 5 28 0 0 75 M285x05 M305x05 OOOO M34 0x0 5 M375x05 O M380x075 M40 0x0 5 OQ OQ 405 0 5 CHIME Polarizing Filter according to Kasemann linear Polarizing Filter according to Kasemann circular Circular Polarizing Filter Linear Polarizing Filter Top Pol Warm Tone Polarizing Filter linear circular Redhancer 491 21 Convers Filters LB Filters 1 5 3 KB 6 KB 12 KB 20 Conversion Filter LB Filter KB 15 Conversion Filters LB Filters KR 1 5 KR 3 KR 6 KR 12 Conversion Filters LB Filters 81A 81B 23 27 Color Correction Filters CC Filters Fluorescent Light Filter 499 F Day UV Black Filter 403 UV Blocking Filter
16. 80 mm on a 6x6 cm medium format camera The result will be a triple image with pleasingly merging contours The positioning of the images can be var ied by rotating the mount of the attachment B W 5x Multi Image Prism Four prism wedges around a square plano parallel center correspondingly generate five nearly identical images one in the center and four around the periph ery all with softly merging contours Here too the most suitable lens is one with a normal focal length in order for the outer four repeated images to be the same as the central one The 5x prism can also be rotated for the best arrangement of the outer im ages and is very popular for use on video cameras B W 6x Multi Image Prism In this prism attachment the central plano parallel section is surrounded by five wedges so that the fi nal picture will consist of a central image repeated five times around the perimeter a total of six images with softly merging edges Like the other attach ments this one should be used on a lens of approxi mately normal focal length It can also be rotated B W 3x Parallel Prism The circular area of this prism attachment is divided into three parallel strips The central strip is a plano parallel plate that does not alter the picture The two outer strips are wedges that become thicker along their long edges towards the central strip The lens therefore sees the image on the central strip re peated twice
17. Warm Tone Polarizing Filter linear circular 000000 Redhancer 491 0000 O 19 Conversion Filters LB Filters 1 5 3 6 12 20 0000 Conversion Filter LB Filters KB 15 Q 56 0000 21 Conversion Filters LB Filters 1 5 KR 3 KR 6 KR 12 0090000000000 0000 000000 00 Conversion Filters LB Filters 81 A 81 B 0000 23 Color Correction Filters CC Filters 2332 27 Fluorescent Light Filter 499 F Day 0090000000000 0 0000 000000 00 UV Black Filter 403 UV Blocking Filter 415 420 00 0 Digital UV IR Blocking Filter 486 eese S JH 27 29 Infrared Blocking Filter 489 Infrared Filters 092 093 099 2333 0 33 35 Filters for b amp w films 021 022 023 040 041 060 061 090 099 0000 000000 000 Filters for black and white films 080 081 99990090000 0000 39 Graduated Filters 501 502 524 543 550 560 561 581 585 590 88484 41 Soft focus attachment Soft Pro QIOIOIOOI IOIOIQODOIO QO O Soft focus attachment Soft Image OO0O0O0 0000000000 Fog attachments Fog 1 2 Softspot OIOQOIOO OO0O0O0 O 43 Special effects attachments Spectra 2 8 48 72 Spectra Spot 0000 Cross Screens 4 6x 8x Star effect attachment Double Sunny 0000 49 Close up Lense
18. angle lens it cannot darken the sky evenly With a warm tone polarizing filter shadow areas are rendered with the correct colors without the clouds taking on a reddish cast Even more saturated colors with a B W Polarizing Filter and a Redhancer B er Pho phs taken direction of tl strongest intensification of a blue sky for a more dramatic rendition of clouds Experiment with colors Many transparent plastic materials such as plastic rulers and crumpled cellophane film show interesting colors when placed be tween two polarizing filters or two polariz ing sheets These colors change when the polarizing filters or sheets are rotated in relation to each other This method can also be used to visualize internal stresses in plas tic replicas of mechanical parts as patterns Decorative cabbage photographed without a filter and with stronger reds using a Redhancer B W Polarizing Filters The high end polarizing foils of the Kasemann type filters are neutral in color they have a higher effi ciency than conventional polarizing foils and they are cemented between high grade plano parallel optical glass The resulting sandwich is then precision pol ished again to achieve highly accurate plano parallel surfaces Subsequently they are edge sealed to pro tect the foil against humidity Brass mounts made on CNC controlled machines ensure precise seating on th
19. artificial light using 100 to 200 W light bulbs or from aged photoflood lamps Therefore this filter is ideal for neutral color repro duction with appropriate illumination Its filter factor is approximately 1 2 B W Conversion Filter KB 6 80 D D This nearly medium blue conversion filter neutralizes the strong red tendency of light at sunrise or sunset out in the open when the original colors of the sub ject are wanted instead of a warm morning or eve ning mood In addition the KB 6 filter is ideal for under corrected filtering of artificial light photo graphs on color negative films When filtration is performed only later during printing there is a visible color shift and full correction leads to a higher loss of light Its filter factor is approximately 1 5 B W Conversion Filter 12 80 B D The deep blue filter KB 12 blocks so much red or ange and yellow that it increases the color tempera ture of very bright halogen and special photoflood lamps of around 3400 K to that of daylight With that kind of illumination and with daylight color re versal film the subjects will be reproduced in their original colors With weaker halogen bulbs or stron ger incandescent bulbs in conjunction with this filter and with daylight reversal film a residue of warmth will be retained for an optimal mood in interior pho tographs Its filter factor is approximately 2 B W Conversion F
20. as its of the attenuation of only the green portion CC Filters Yellow 05 10 20 40 Page 23 Special Filters F Day 403 415 420 486 489 P 27 I lI D 489 420 o MIEN A m 60 or os oos zo 61 2 5 2 l 0 amp 0 300 400 500 600 700 300 nm 400 nm 500 nm 600 nm 700 nm CC Filters Red 05 10 20 40 Page 23 Infrared Filters 092 093 099 IR Special Filters P 29 ERRERA eer SREP E LE L T M LII _ O l l 5 40 5 40 5 8 20 20 2 5 TL amp 0 300 nm 400 500 nm 600 700 nm 500 600 700 nm 800 900 CC Filters Green 05 10 20 40 Page 23 Black amp White Filters 021 022 023 040 041 33 CL ATT ere YIAN 5 TN E BON S 02 04 e NE l E Transmission Pure transmission 7 76 300 nm 400 nm 500 nm 600 nm 700 nm 300 400 500 600 700 CC Filters Blue 05 10 20 40 Page23 8 Filters 060 061 080 081 090 091 35 100 100 80 80 60 _ 60 58 8 40 5 40 20 20 0 2 o 300 nm 400 nm 500 nm 600 nm 700 nm 300
21. his or her very strict criteria Though a photograph might bring back pleasant memories to its author or 66 represent a particularly difficult photo graphic situation it might not necessarily 67 appeal to others Those who wish to pre sent their photographs successfully be it in exhibitions publications or slide shows should set themselves the most stringent standards for the aesthetic and technical quality of their pictures It is far better to show 80 first class and perfectly sharp slides rather than 200 that may be infor mative but mediocre images Magnifier a lens for the eye If you place high demands on picture quality you should not cut corners on the lens If you want to evaluate an image critically you should not skimp on the magnifier The simple single lens magni fying glass from the flea market should at best evoke youthful joys of discovery in the playroom A high grade magnifier that covers the full slide or negative format of your 35 mm or roll film camera at high mag nification and that also permits the ex amination of the finest details is indis pensable for critical evaluation The most important characteristic of a magnifier is a first class optical system that renders a sharp image with rich con trast has minimal distortion and that permits eyeglass wearers to view the full image all the way into its corners A matte translucent base that pro vides uniform largely shadow f
22. is not too high and the aperture is stopped down sufficiently which is customary because of the shallow depth of field for close ups Scale ratio or distance The shortest possible focusing distance for lenses close up and macro accessories is usually cited as a performance criterion for their macro capability This value does not however reveal much about the im age size of the subject A more relevant parameter is the reproduction ratio that can be achieved i e the ratio of image size to object size or the smallest frame filling subject size For example a 35 mm lens equipped with a B W NL 2 close up lens 2 diopters when set at 0 3 m 113 4 in on its focusing scale at a dis tance of 14 cm 5 1 2 in will cover an object size of approximately 11x16 cm 43 8x 61 4 in at a reproduction ratio of 1 4 5 whereas a 100 mm lens with the same close up attachment set for 1 m 3 1 4 feet on its focusing scale at a dis tance of 35 cm 133 4 in fills the frame with an even smaller object size of 8x12 cm 3 8x4 4 in at a scale ratio of 1 3 3 4 1 re i If you wish to consistently experience the gratifying joy of successful photography the best way is to avail yourself of high quality reliable equipment Attention should be paid not only to cameras and ESSORI ENS 51 lenses but also to small things that are sometimes overlooked as seemingly irrel
23. of the shorter focal length of their lenses is much more sensitive to dirt on the front element of a lens Care of B W Filters Only clean B W Filters will guarantee that the very high quality of materials and fabrication will contribute to perfect image quality The hard water and dirt repelling MRC coating helps you to keep your B W Filters free of scratches and lint If dust water or dirt has to be re moved in spite of all the precautions please take the following rules to heart Never rub dry dirt or dust off the surface because they may contain minis cule quartz particles that are much hard er than glass and that can scratch the latter nearly as badly as diamonds can First gently whisk the dust off with a very soft brush before breathing on the sur face and then using a soft cloth prefera bly the B W Photoclear microfiber cleaning cloth and extremely gentle pres sure to wipe the surface clean When the dirt is very hard to remove a bit of saliva is the best solution always available guaranteed free of abrasive materials oil and aggressive chemical substances Never use a paper tissue for cleaning because it leaves too much lint and pa per fibers cling to glass because of elec trostatic charges UV SKYLIGHT PROTECTION FILTERS Oo M CO Te Without a neutral density filter a small aperture With Neutral Density Filter 103 the lens aperture can be renders excessiv
24. on page 64 Special mounts with bayonets for Rollei and Hasselblad lenses round out the B W line of filters All the available types of B W mounts as well as the unmounted sheet filters are described in detail and illustrated on the double page spread that follows COATINGS MOUNTS 56 57 B W Standard Filter Mount F Pro Compared to the earlier B W standard filter mount the B W Standard Filter Mount F Pro has been im proved considerably While maintaining the excellent quality of materials fabrication and high mechanical stability the new F Pro mount has become thinner so that now it can also be used on many wide angle lenses without the danger of vignetting An exact focal length limitation cannot be stated because vignetting depends not only on the height of the filter mount but also on the design of the front of the lens Nevertheless the following can serve as a guide The B W standard filter mount F Pro can be used without vignetting on 35 mm camera lenses with focal lengths of 35 mm most 28 mm lenses and in many cases even on 24 mm lenses Another advantage of the new F Pro filter mount is its modified retaining ring which is no longer thread ed in from the front but holds the filter glass in place from the back This prevents the retaining ring from being accidentally loosened during the removal of an additional filter or a lens hood that has been screwed in too tightly B W SLIM Wide Angle Filter
25. once on the left strip and once on the right strip Depending on the rotation of the attach ment the triple repetition of the image can be ar ranged horizontally vertically or diagonally B W 6x Parallel Prism One half of this attachment is a plano parallel plate through which the image will be recorded quite nor mally The other half consists of five parallel wedges of equal widths whose angle of inclination of the front surface increases from the center towards the outside thus repeating the main image five times in parallel with gently merging contours This attach ment can also be rotated Use medium focal lengths Wedge shaped prisms attached to the front of the lens deflect the incoming light so that prisms with appropriate wedges and positioning lead to a multiple reproduction of the same portion of the subject in different locations on the im age Because the effect of these attach ments is affected by the focal length of the lens that is being used the shape of the wedges on B W prism attachments is tailored to medium focal lengths nor mal to short telephoto lenses or zoom settings within that range Another rea son why lenses with short focal lengths are not ideal for use in combination with prism attachments is the fact that their greater depth of field makes the various repeated picture sections abpear more sharply distinct from one an other in stead of letting them overlap s
26. red by combining a magenta and a yellow filter With these filters the photographer can reduce the number of filters placed in the light path 05 10 20 40 05 10 20 40 Filter Factor for Daylight and for Tungsten Light 11 11 13 1 4 11 12 14 15 1 2 13 15 19 Ll 12 13 125 11 11 12 1 4 11 11 12 13 12 13 15 21 11 12 14 19 11 12 13 15 11 12 13 15 12 13 16 21 12 13 17 24 CC FILTERS COLOR CORRECTION LB Filters versus CC Filters In order to understand the differences between LB Light Balancing or Conver sion Filters and CC Color Correction Filters one has to divide white light into its spectrum of violet blue blue green green yellow orange and red When white sunlight reaches earth after pass ing through the layer of air that enve lopes the earth it has approximately the NM 22 same intensity energy distribution across que its entire spectrum 23 Like the sun incandescent bulbs are thermal radiators but their filaments have a much lower surface temperature e g 2700 K than the sun 5600 K Therefore in accordance with the laws of physics they emit far fewer short wave length light than long wave light in other words less blue than red This imbalance can be corrected with LB or conversion filters Blue conver sion filters for photographs on film bal anced for daylight exposures absorb little green more yellow and even more red In other words the absorption increases as the wavelengths inc
27. reducing color yellow filters for the suppression of the violet color fringes of Fraun hofer achromats UV IR blocking filters are needed for astrophotography with certain CCD cameras B W Astro Filters have M 28 5 x 0 5 or M 48 x 0 75 threads see table on page 63 4th and 5th column from the right so that they can be screwed into the inside threads of the attachment tubes of 1 25 or 2 eyepieces or mirror or prism diagonals or into filter revolvers The first class optical quality homogenei ty plano parallelism and surface quality of the filter glasses of these B W filters is particularly effective when they are positioned for instance in binocular observation well ahead of the primary focus TYPES MOUNTS 58 59 transmission is stated each wavelength the per Transmission centage values can be graphed in the form of a curve The technical term Transmission in reference to an that accurately characterizes every color filter This is optical system describes the percentage of incoming not only important in technical applications but also light 100 76 that is actually transmitted When the in any photography where the light source is not a UV 010 Skylight Filter KR 1 5 Page 9 Conversion Filters KB 1 5 3 6 12 15 80 A 20 19 I wee rT ASS ke AZI _ M _ 60 EC
28. when aerial perspective is to be accentuated Tonal separa tion in the photography of objects is also increased Its filter factor is approximately 2 B W Light Red Filter 090 25 oc 590 GU This is the classic filter for architectural photography White facades glow brightly the blue sky is darkened dramatically and clouds become more impressive It is also excellent for spectacular landscape photo graphs with greatly improved distant views Its filter factor is approximately 5 B W Red Filter 091 29 nc 630 Compared to the lighter red filter described above this one even darkens the reds near the yellow tones in the spectrum as its transparency only begins in the orange red region It produces dramatic effects and extreme tonal separation for graphic effects That accounts for the large filter factor of appr 8 MEIST FILTERS BLACK amp WHITE FILMS More differentiated greens Why does the use of a yellow green filter lead to a much better differentiation of green tones in nature and landscape photography Here is the answer Green can be a spectrally relatively pure green but it can also be a blue green amp yellow green mixture Whereas pure green is readily transmitted by a yellow green filter an equally bright mixed color green 34 will have its blue green component re duced so that it will darker a 35 black and white print darker than the gray
29. 0 K artificial light the Mired value is 1000000 3000 333 3 The difference between the Mired value of the film and the Mired value of the light is the Mired value of the correction filter that correctly tailors the light to the film 178 6 Mired 333 3 Mired 154 7 Mired or 15 Decamired A positive value indicates a reddish KR filter a negative value indicates a bluish KB filter Thus the filter required to adapt the 3000 K halogen light the slightly low value results from the mains voltage being lower than its nominal voltage to a 5600 K daylight color film is a blue KB 15 B W Conversion Filter A diagram for Kelvin Mired conversion and for the determining the correct filtration for MIRED photographs can be found on page 65 B W Conversion Filter KB 1 5 82 A The conversion filter with the most delicate shade of blue attenuates the slightly higher red orange and yellow components in order to produce a neutral color rendition It can also be used for subjects that are to be shown with a cooler coloring In addition they adapt the color temperature of the very bright photoflood lamps to color films balanced for halogen light of 3200 Its filter factor is approximately 1 1 B W Conversion Filter KB 3 82 C With about twice the correcting effect of the previ ous filter this conversion filter removes the orange red color cast that appears on photographs made on tungsten reversal film with
30. 4x Universal magnifier A highly versatile magnifier with bril liant high resolution optics Eyeglass wearers can see the entire image comfortably all the way into the cor ners for fatigue free working Distor tion free even at greater eye relief In terchangeable bases skirts for view ing reflection copy or transparencies 6x ASPH Maximal magnification Stronger magnification for the most critical evaluation of sharpness while still covering the full 35 mm format An aspherical surface assures the best performance Ideal for transparency negative or ground glass evaluation Interchangeable bases skirts for view ing reflection copy or transparencies 10x Detail sharpness Ideal for examining the very finest de tails with highest resolution Equipped with a high grade optical system for brilliant imaging quality of practically microscopic resolution Comfortable viewing for fatigue free working L 10x Illuminating magnifier Optically identical to the 10x magnifier but equipped with white light LEDs for bright incident illumination with minimal energy consumption The button cell can easily be replaced ILLUMINATING MAGNIFIERS Critical evaluation of your photographs is worthwhile The photographers that are successful and who s work is admired for excellent image quality are diligent in their critical evaluation of all of their photographs and the rejection of those that do not meet
31. B W Medium Yellow Filter 022 8 cc 495 Gig With stronger blue suppression which extends into the blue green the effects described above are slightly stronger in the same types of applications Clouds in the sky look very natural but not yet dra matic Distant views with light haze become clearer An ideal filter especially for landscape and plant photographs Its filter factor is approximately 2 B W Dark Yellow Filter 023 15 scuorr 530 The even greater blue suppression and the attenua tion into the blue green range leads to a further in crease in the effects described above Interesting for snow scenes under a blue sky because the darkened blue shadows in the snow make the shapes of the landscape look more dimensional Freckles and skin blemishes are diminished strongly but lips are ren dered more pale to compensate for you may use a dark lipstick Its filter factor is approximately 3 B W Yellow Orange Filter 040 16 550 The effect of this filter is quite powerful It darkens violet and blue very strongly green strongly it even darkens yellow green a bit Landscape and architec tural photographs have an increased virtually graph ic contrast clouds in the sky already look dramatic Because skin tones are strongly lightened in relation to the green tones of plants this is a favored filter for nude photography outdoors because it raises the contrast between the lighter
32. Green 561 Because of its vegetation color this graduated filter is especially suitable for the lower half of an image when used in combinations with other graduated filters that are being used to darken or to alter the color of the sky With such filter combinations the TTL exposure metering should be performed with the filters in position on the lens B W Graduated Filter Blue 581 This is an excellent solution when the sky isn t blue enough It can be used effectively in combination with another graduated filter for the lower half of the image so that in such a combination the sky will not be rendered too brightly or too pale Example sand dunes the sea using a graduated B VW Tabac Filter for the lower half and a graduated Blue Filter for the upper half of the image Additional graduated color filter variants that are available Yellow Green 560 Purple 585 Increase the exposure only modestly for in the dense portion of the graduated filters so that the effect of the filters won t be reduced too much GRADUATED FILTERS 38 39 b Harsh sharpness without attachments Flattering soft focus with Soft Pro Noticeably softer with B W Soft Image B W Soft Focus Tip f 4 The type of soft effect filter will determine what level that the effect of aperture con veys to the image The aperture should be chosen judiciously and according the fol lowing rules 1 The aperture should not be smaller th
33. That E is why it is practical to convert the Kelvin values of 65 light and color film into Mired values for finding the right filter strength as described on page 18 Those who prefer an easier method rather than performing computations can use the following table to find the Kelvin and Mired values for various light conditions and the correct filters for the color reversal film that is being used note the direction of the arrow Kelvin Mired Conversion Filter 10000 100 Clear blue sky in the shade 9000 8000 6 Daylight foggy weather Daylight overcast sk 7000 150 KR 3 8 y 6000 UE Sunlight blue sky E Y Sunlight white clouds 5000 200 S Eae Sunlight mornings evenings 4500 Sunlight shortly before sundown KB 6 Fluorescent Tube White 4000 250 KR 6 Moonlight Carbon Arc Lamp Fluorescent Tube Warm CC 3500 300 12 Y KR 1 5 Halogen Bulb Nominal Voltage 3000 KB 15 t 1 5 Halogen Bulb Mains Voltage 350 KB 3 Krypton Bulb 500 Watts 6 X Household Bulb 100 Watt KB 20 Household Bulb 60 Watt 2500 400 Household Bulb 25 Watt Imprint Publisher Text Product photos Sample photos Layout Design Printing Jos Schneider Optische Werke GmbH Business Unit B W Filters D 55543 Bad Kreuznach Ringstr 132 Phone 49 0 671 601 125 Walter E Sch n DGPh D 81673 Munich incl tables diagrams Peter Lebeda Jos Schneider Optische Werke GmbH Mart
34. aining time but to protect the lenses because every soiling and every cleaning involves the un necessary potential of dangerous damage to the sensitive surfaces and coatings of the glass which should be avoided When aggressive substances reach the lens or filter surfaces or when fine dust contains tiny quartz particles which is the major component of sand even a slight pressure during the cleaning pro cess can cause damage as quartz crystal is much harder than glass and readily scratches it like a diamond Thus the recommendation clearly has to be that the use of a front lens cap and when the lens is not attached to the camera a rear cap should be a matter of course The front lens cap should only be removed just before the lens is to be used for an exposure And as soon as the cam era is no longer needed to be ready for photography or when the lens is removed and stored in the gadget bag the protec tive caps should be re attached Those who follow these rules will al ways have clear front and rear lens ele ments the best guarantee for their ex pensive lenses to render their very best performance in terms of brilliant images with high contrast impressive detail sharpness and rich shadow details LENS CAPS 54 55 a z E B Ej mim Same E mss n P 1 a 9 LN
35. an an f stop number that is approximately 1 5 of the focal length of the lens in mm For example on a normal 50 mm lens on a 35 mm camera the smallest f stop should f 11 28 mm lens it should be f 5 6 This restriction is not as critical with tele photo lenses Stopping the lens down more can make the soft focus structure of the at tachment become visible as a pattern Full image sharpness without attachments Reduced contrast with fog attachment Fog 2 The intentional choice of the depth of field for use of a soft focus effect can be come a creative interplay between sharp ness and unsharpness so that the effect of a skillful combination of both can be en hanced even further To achieve the most dramatic soft effect use a larger aperture 3 One of the most important applications of soft focus attachments is in portraiture The ideal focal length for a lens on a 35 mm camera is between 85 and 135 mm and in conjunction with an aperture of f 4 Pleasing soft focus with Softar 1 Considerably softer and flattering with Softar 2 SOF TAR B W Soft Focus Attachment Soft Pro The effect of this B W soft focus attachment is ated by fine lenticular protrusions that have been applied to a high grade plano parallel plate of glass in a random pattern The light passing through between these protrusions creates a sharp core image for ac curate focusing and great detail This is an important featu
36. aphy The 10 diopter power makes it possible to explore true macro ranges without the need for an expensive special lens in order to reproduce tiny subjects at enormous proportions appr 1 2 to 1 1 5 Apertures of f 8 or 11 are recommended for good corner to corner sharpness Because of its great power it is also suitable for use with digital cameras MEI CLOSE UP LENSES Superior close up lenses The best image quality in extreme close up photographs is achieved with macro lenses But such lenses are expensive If you only take occasional close up pic tures such an expense might not be jus tified An alternative approach is to use close up lenses or extension rings Not only are close up lenses the less expen sive solution they can yield better quality 48 at reproduction ratios of up to appr 1 2 5 UE i e at the smallest frame filling object 49 size of 6x9 cm or 23 8 3 inches as they adapt the farsighted main lens to the close up range And they have the addi tional advantage that they do not cause a reduction of effective light so that the selected aperture remains practically identical with the effective aperture Ex tension rings strongly reduce the effective aperture thus darkening the viewfinder image and requiring exposure corrections Therefore there is no reason to re gard close up lenses as less desirable emergency solutions as long as the power of the chosen close up lens
37. astronomy for photographs of the sun and for recording the relative movements of heavenly bodies as light traces in ex tremely long exposure times For photographs of the sun this filter must be positioned in front of the lens and under no circumstances should it be located near the primary focus in front of or behind the eyepiece because of the intense heat at those loca tions It must not be used for observation of the sun danger of blindness due to its greater transmission in the infrared range The filter factor is 10000x B W Neutral Density Filter 120 With its light reduction capability of 20 f stops this B W ND Filter is used for the same astro photo graphic applications as ND filter 113 when an even greater light attenuation is required In spite of its much higher density this filter too must not be used for visual observation because of its transmission in the infrared range The filter factor is 1000000x NEUTRAL DENSITY FILTERS 10 11 With B W polarizing filters reflections on glass lacquer on nearly all plastic materials and other electrically non conducting surfaces can often be reduced or even eliminated B W Polarizing Filters provide you the control over how much reflection you wish to remain because the light reflected at an angle of about 40 to 70 by these surfaces is strongly polarized Its transmission reduced blocked or even enhanced in relation to the re maining unp
38. bodies and darker land scapes Its filter factor is approximately 4 B W Red Orange Filter 041 22 06 5701 The intensified effect of this filter borders on the abstract It darkens a blue sky with clouds to re semble the mood of an impending thunderstorm Architectural photographs gain clarity and drama This filter is also interesting for many black and white close up photographs of flowers when dark yellow orange or red blossoms have almost the same brightness as the surrounding greenery This filter is used to render the flowers in lighter shades of gray Depending on the subject its filter factor is 4 to 5 FILTERS FOR BLACK amp WHITE FILMS Colors become gray shades Black and white films should render all colors in shades of gray in such a way that their brightness values look natural Older photographers can still remember that in earlier days yellow filters were a must for landscape photographs and for portraits Even films that were sensitized panchromatically ostensibly to match human brightness perception still ren 32 dered blues too lightly and reds too dark ly Even though today s black and white 33 films no longer have that shortcoming filters are still necessary for controlling the photographer s translation of colors into shades of gray Black and white photographs often lack impact because colors that are well differentiated in nature be equivalently luminous in shades of g
39. cesses with extreme brightness such as steel furnaces incinerators glowing filaments in halogen and other bulbs The filter factor is 1000x ae eat Charming selective sharpness Modern high speed lenses produce bright viewfinder images in reflex cameras and make fast shutter speeds possible in all types of cameras even with slow speed films or under poor light conditions But their large apertures can also be used as an interesting creative element At wide apertures the depth of field is reduced so much that eventually only the main subject will be rendered sharply whereas the fore and background will be unsharp This also focuses the attention on the main subject in a creative sense it draws the attention of the viewer as if by magic relegating everything else into the background In intense brightness how ever with high speed film or a short focal length with correspondingly higher depth of field using a large aperture to achieve the desired selective sharpness effect may not be possible without incurring over exposure This is when B W neutral density filters provide the solution When the shutter speed is reduced by two or three steps instead opening the aperture for instance a neutral density filter can be used for equally creative blur effects with moving subjects B W Neutral Density Filter 113 With its light reducing capability of 13 f stops this B W Neutral Density Filter is used in
40. collapsible lens hood can remain on the lens permanently because it only lengthens the lens minutely in its col lapsed state requiring hardly any additional space in the gadget bag This in turn increases the chances that the lens hood will already be in place in hectic situations avoiding lost time screwing sturdy hoods into the front of the lens barrel or removing them LENS HOODS B W Collapsible and Metal Lens Hoods 52 53 ADAPTER RINGS B W Adapter Rings for various filter sizes Thread on Filter thread or bayonet Adapter Adapter rings serve to accommodate filters close up the filter on the lens number lenses and other attachments to lenses with differ BE 075 bdo 75 25 ent filter thread sizes For example with a camera 54x 075 6 d outfit that includes lenses with 49 mm and 52 mm 52x 0 75 6 filter threads adapter rings make it possible to use 49 x 0 75 6a 52 mm filters on both types of lenses Not only does 48 x 0 75 6b this save money that can be invested in a greater se 52 x 0 75 Hasselblad Bayonet 50 E lection of filter types it also saves space and weight 60 x 0 75 23 in the gadget bag Caution When a smaller filter is 58 x 0 75 5 b adapted to a lens with a larger filter thread there is 55x 075 26 the probability of vignetting 49 x 0 75 8 48 x 0 75 8a B W Adapter Rings listed according to their filter side thread sizes 46 x 0 75 8b 43 x 0 75 8c Thread on Filter thread or bayonet Adapter 40 5 x 0 5 8e the fi
41. consist of high grade but very sensitive original Kodak foils cemented between precisely fabricated plano parallel optical glass discs that are edge sealed for protection against humidity and immun from finger prints scratches and dirt Subtractive color mixing occurs when filters are placed in the light path on top each other Each filter absorbs its com plementary color thus a yellow filter absorbs or re duces blue light Because absorbing or reducing is the same as subtracting this type of color mixing is called subtractive color mixing Cyan a greenish blue color Magenta purple and Yellow sometimes collectively referred to as CMY are the colors used in subtractive color mixing Nearly all the filter col ors needed for the correction of color casts can be generated with just these three CMY filter colors Additive color mixing occurs when several light sources each with CC Density Cyan Magenta Yellow Red Green Blue a filter of a different color illuminate the very same object Each light source adds more light to the light that already exists which is why this kind of color mixing is called additive Red Green and Blue RGB are the primary colors in additive color mix ing Even though colors of several filter layers are mixed subtractively these additive filter colors are helpful Otherwise red green and blue would have to be simulated by overlaying two subtractive primary colors e g
42. d the light sources similar to the effect produced by 48 ray Spectra at tachment It is most effective on lenses with short focal lengths or with apertures of f 8 or smaller B W Spectra Attachments have a very fine microprism structure that is barely visible to the human eye They stretch out the light sources in the form of rays that are di vided into their spectral color components B W Star Cross Screens have fine grating structures on the sur face of high grade optical glass that produce the ray effects by means of diffraction Ideal point light sources Both the Spectra prism attachments as well as the radiating attachments direct a little light from every bright image point in the direction provided by the respec tive attachment which can be rotated This always results in a minimal amount of soft focus when the point source of light is not very bright Therefore these at tachments should not be used with sub jects that have normal contrast Instead they are most effective with dark subjects the soft focus effect remains invisible with such subjects that include very bright point shaped light sources which lead to pronounced star radiating effects B W Attachment 4x Cross Screen The star patterns created around light sources by star screens are not spread out as colorfully as those created by Spectra attachments Instead their colors are less pronounced The rays begin r
43. diameter The overview tables for all B W fil ters on pages 62 to 64 show the kind of coating for each type and size of filter Filter mounts When purchasing a filter you should take into ac count both the quality of the optical glass and the coatings as well However don t overlook the quality of the filter mount as it is also very important The mount must have sufficient strength to protect the breakable glass hold it without mechanical ten sion but also without play It should provide a good grip and have precisely fabricated threads for easy attachment to and removal from the lens It should not be long enough ring height to cause vignett ing It should have a clearly legible and descriptive engraving Its inside surfaces should be as reflection free as possible preferably matte black B W filter mounts meet these requirements to per fection As a rule they are made of sturdy brass on highly accurate CNC machines The filter glass is kept securely in place by a threaded retaining ring that is fabricated with equal accuracy The mount surfaces have a black chrome finish the labeling is clearly legible the inside surface is matte black The standard mounts are already designed to be thin enough so as not to cause vignetting on moderate wide angle lenses There are B W SLIM mounts for wide angle lenses with shorter focal lengths and there are also oversized mounts for extreme wide angle lenses see table
44. e previous filter i e by two aperture stops it transmits 25 of the incoming light this graduated filter al ready produces quite dramatic effects Because of the increased difference in brightness it is even more important for the horizon line not to be positioned too far from the center of the image B W Graduated Filter Red 590 This graduated filter is often referred to as the sun set filter because it can simulate a missing red sky in the evening or in the morning or to enhance one that is too pale when the line of sight is towards the sun By the sea or by a lake the horizon line should be positioned high enough for the red portion of the filter also to cover the reflection in the water B W Graduated Filter Orange 524 The somewhat more delicate coloring of this gradu ated filter is recommended when the correction of the sunset mood is not to be too pronounced or when a certain amount of red coloring is already present so that only a small enhancement would be sufficient With heavy gray thunderstorm clouds it can produce a nearly awesome storm mood B W Graduated Filter Violet 543 With grazing light and a sparse exposure this gradu ated filter with its somewhat unnatural color can produce a ghostly macabre moonlight effect So it is more suitable for abstractions rather than enhance ments of natural moods An interesting effect can be achieved by using it in combination with th
45. e gradu ated green filter 561 for the lower half of the image B W Graduated Filter Tabac 550 Those who have experienced a sandstorm in the desert will never forget that mood With this gradu ated filter one can approximate that mood slightly threatening yet still pleasantly The tobacco color is discreet not overly colorful so that it never appears gross nor overlay the existing colors as much as the other more intense graduated colors ae Eat Correct exposure metering When only a single graduated filter is used it is nearly always for darkening an excessively bright sky Exposure metering should be performed without a graduated filter with the camera s meter or a sepa rate manual exposure meter measuring the foreground that is to be exposed correctly The sky will then nearly always show the desired effect With the combination of two gradu ated filters one of them upside down in relation to the other for instance a red one for the sky and a green one for the foreground take the measurement through both filters For more dramatic effect a slight under exposure perhaps by half an f stop is often desirable Rotating filter mounts The mounts of graduated filters can be rotated so that the line of transition be tween the colored and the clear half of the filter can be adjusted in relation to the subject without appearing unnatural B W Graduated Filter
46. e lens Discriminating photographers regard the B W Polarizing Filter to be the very best of all polarizing filters They are well suited for applications that require the highest possible imaging quality especially with high speed telephoto lenses and apochromatic lenses They are available as linear and circular polarizing filters mostly with MRC and also with SLIM or oversized wide angle mounts B W Circular Polarizing Filter Gu Highly efficient standard circular polarizing filter for all cameras with beam splitters in the light paths of their TTL exposure meter and with autofocus lenses Circular polarization has the same pictorial effect as linear polarization but allows for proper exposure metering and or autofocus distance settings B W Polarizing Filters are available uncoated and with B W s proprietary MRC coating B W Top Pol Linear Polarizing Filter Linear polarization filter for SLRs and rangefinder cameras without beam splitters in their light paths High quality optical glass ensures excellent pictorial quality B W Top Pol Polarizing Filters are available uncoated and with B W s proprietary MRC coating B W Warm Tone Polarizing Filters These filters are special versions of the B W Linear and Circular Polarizing Filters with an KR 1 5 correc tion filter or an 81 A warm tone filter as protection glass KR 3 or 81 B on request This combines the optical qualit
47. e only in the infrared filters must be used to suppress the visible or to attenuate it strongly so that the weak image produced by the infrared radiation will be sufficiently prominent Infrared photographs are attractive in many ways Because of the nearly white reproduction of the chlorophyll green of vegetation infrared black and white pho tographs render landscapes as if they were self illuminating or immersed in an extraterrestrial light the moonlight ef fect Infrared color photographs have a fairy tale effect because colors are re versed The film renders highly infrared reflecting plants in orange to purple red tones while filters suppress the blue and green components that are also present In any case the pictorial results are diffi cult to predict therefore they are always good for experimentation and surprises Because there are no exposure me ters that are sensitive exclusively to the sensitivity range of these infrared films it is difficult to calculate exact exposures and conversions by means of filter fac tors This is due to the fact that two sub jects that are equally bright in normal visible light might reflect infrared radia tion at significantly different rates In oth er words they can have very different brightnesses as far as the infrared film is concerned Therefore it is always advis able to make a series of three to five dif ferent exposures Don t be stingy with film because once
48. e reproduction without a prism attachment The 6x multi prism repeats the realistic central portion of the image five times creating a graphic pattern The slightly rotated 6x parallel prism repeats a portion of the image to the right six times In this example a close up prism has almost amortized itself through wondrous money accumulation The 3x multi prism can emphasize an architectural pattern and exaggerate it to maximum PRISMS B W tip Dark surroundings For the adjoining image repetitions to flow into one another softly the focal length of the lens that is being used should not be too short and its aperture not too small On a 35 mm camera the ideal parameters are a focal length between 50 and 100 mm and an aperture between f 4 and 8 Because the colors of neighboring portions of the image blend in the overlapping area this causes paler colors and lower contrast For that reason subjects with dark back grounds dark surroundings are recom mended for this type of photography in or der to retain pure colors and clear shapes B W 3x Multi Image Prism The three wedges of equal size that meet at the center of this prism attachment are made of high grade optical glass and they deflect the light in such a way that the lens looks at the same subject in three directions The lens should have an approximately normal focal length i e 50 mm on a 35 mm camera or
49. e various component colors of white or any light is called its spectrum In nature we can see a spectrum in the form of a rainbow Rainbow colors are pure colors because each color can be defined by a specific wavelength On the other hand an object that appears green for example does not necessarily reflect just one wavelength or of a nar row band of wavelengths It also may absorb a variety of frequencies significantly blue and red It reflects the remaining spectral colors this mixture of which is perceived by us as that shade of green If we re plenish this mixture of colors with the missing shade of magenta we will once again see white Such op posite colors when combined form white are called complementary colors Other examples are yellow and blue or red and cyan When light of one color is added to light of an other color this is called additive color mixing As an example this is the case when a red spotlight and a green spotlight illuminate a stage and we see yellow light as the combined added color where the two spotlights overlap But if we mix colored pigments or if we paint or print colors over each other some thing different happens each colored pigment ab sorbs the part that is complementary to its own col B W FILTER TECHNOLOGY or In other words it takes away something from white light so that less light is reflected than it would be by each color individually Therefore this kind of color
50. ely large depth of field opened up in order to emphasize an important detail I dert E Em 1 i H i deu Without a neutral density filter fast shutter speed B W 106 Neutral Density Filter permits to use a shutter virtually freezes the surging surf speed that makes the surging water appear to flow again Without a neutral density filter the camera A B W 110 Neutral Density Filter blurs movement produces a snapshot of the moving scene making it virtually invisible B W Neutral Density Filter 101 Gu The lightest Neutral Density Filter attenuates the light by one f stop log density 0 3 which can be beneficial for instance for the correct exposure of high speed films when the brightness of the subject is still too high for the fastest shutter speed and the smallest aperture It is recommended especially as complement to B W Neutral Density Filter 102 for fine adjustments The filter factor is 2x B W Neutral Density Filter 102 This Neutral Density Filter reduces the light by two f stops log density 0 6 and it is the most pop ular ND filter in photographic work It offers many benefits for instance f 4 instead of f 8 for selective sharpness instead of a great depth of field or 1 15 s instead of 1 60 s for a flowing instead of a frozen waterfall It has excellent color neutrality costs less than the denser filters and is recommended as part
51. en larger angle of view and especially for wide angle lenses for large format cam eras B W has created special polarizing filters The latter have an oversized mount with larger filter discs see above and they are equipped with the particularly high grade linear and circular polarizing foil according to Kasemann After the cementing process these filters are re ground and polished to ensure precise plano parallelism and then they are edge sealed The advantages of polarizing filters ac cording to Kasemann are described on page 15 Special Polarizing Filters are also available in the 67 E size that fits the 28 mm f 2 8 Schneider PC Su per Angulon lens The mount of this filter was de signed so that it will not interfere with the move ment of the front floating element group while the 28 mm PC Super Angulon lens is being focused B W Sheet Filters unmounted glass filter squares Bellows universal filter holders and special lens hoods that can hold unmounted glass filter squares are used primarily on medium and large format cameras Because the highest image quality is a major priority in professional photography B W offers key filters in the square 75x75 mm and 100x100 mm sizes These are ground and polished plates of high grade optical glass that are superior to the familiar plastic filters with regards to homogeneity plano parallelism and surface quality Neutral Density 101 ND 0 3 1 f stop Neutral Des
52. enge and master it with perfection B W filters that transmit ultraviolet or infra red light but which block or severely limit the visi ble spectrum can reveal otherwise hidden worlds when used in conjunction with appropriately sensi tized films On the other hand different B W Special Fil ters prevent disturbing light and radiation that dis torts the pictorial impression from passing through the lens and reaching the film The B W Special Filter FL Day should be an indispensable accessory for every photographer because it suppresses the green hue of the light emitted by fluorescent tubes While inconspicuous to our eyes it can cause unpleasant green cast in color photographs Fluorescent tubes produce a disturbing green cast B W Filter F Day produces pictures with neutral colors Fluorescence photomicrograph of human chromosomes with UV illumination and B W UV Blocking Filter 420 DIGITAL B W Filter Tip Available Light Nearly every color cast can be corrected by means of a B W Special Filter on the lens provided that a uniform kind of light illu minates the subject Things become problematic however in mixed light sources such as electronic flash used in addition to fluorescent light illumi nation e g in an office shot or in a shop Because a B W Filter F Day will not only eliminate the green cast of fluorescent light it will of course also filter the daylight color of f
53. ess with the use of a B W Graduated Filter 581 B W graduated color filters are primarily intended for color photography and are used mostly for photography on color transparency film the effects described on the right When color negative films are used the processing laboratory should be informed so it won t correct the effects from the image But all B W graduated color filters can of course also be used with black and white films often with very interesting effects With black and white film the two graduat ed gray filters will have the same effect as they would have with color film And with the graduated color filters you can estimate the effects on the respective half of the im age by checking the effects of filters of the same or similar color listed on pages 33 35 The field takes on autumn colors with the use of an opposing combination of B W Graduated Filters Blue 581 and Tabac 550 B W Graduated Filter Gray 501 The neutral gray half of this filter transmits 50 of the incoming light so that it darkens the respective portion of the subject by one f stop without altering its colors For example when the sky is too bright in relation to the landscape this is an ideal amount for good detail rendition in the clouds and for preventing the sky from being washed out by over exposure B W Graduated Filter Dark Gray 502 Because it attenuates the light twice as much as th
54. evant That is why we supplemented the line of B W filters with addition al accessories that are necessary or useful when used in combination with filters For safe and dustproof storage of filters we offer choice of rigid soft padded pouches When in spite of all precautions filters or lenses become soiled with dust fingerprints or water spray the lint free and washable B W high tech microfiber cleansing cloth will quickly restore the surfaces to impeccable conditions To protect the exposed front element of a lens from mechanical damage while at the same time shielding it from contrast reducing stray light we offer metal and collapsible rubber lens hoods that are specifically optimized for wide angle standard and telephoto lenses And our adapter rings make it possible to adapt a single filter size to various lenses with dif T ferent filter chreads so that it won t be necessary to acquire complete filter sets for every lens Photo Thorsten Meywald i m EN NN T v ns CLEANING STORAGE B W Photo Clear Micro Fiber Cleansing Cloth m There is not a better cleansing and care cloth for filters lenses and other sensitive optical equipment like binoculars spotting scopes and eyeglass lenses and even slide cover glasses than the B W high tech microfiber cleansing cloth It is free of chemicals and 4 lint it cleans well but gently and it washed
55. ght sources outside the central image region Spectra 2 produces two rays to the top left and the bottom right with the colors of the respective spectrum fanned out B W Use the effects sparingly B W Attachments make extraordinary striking photos possible Some shots only develop their true values with these attach ments while others are given that extra kick However as with all unusual effects if they are overused they lose power and appeal and can even have the reverse effect and just look contrived The great variety of B W Attachments for special effects are always at your disposal but should be used sparingly and only when they really do create that surprise effect B W Tip Rotate the effect filter slowly during video shots All Attachments for special effects can naturally also used for video shots and should also be used sparingly and with care in these cases The effects can be increased even further with videos by slowly rotating the attachments during shots Without an effect filter With 8 Star Cross Screen B W Attachment Spectra 2 2 directions The microprism structure of this attachment pro duces arrow like rays emanating from light sources or reflections in opposite directions with the colors of the respective spectrum fanned out The effect is most dramatic with a dark background The rotating mount makes it possible to select the optimal direc t
56. graphs of pure red and infrared images possible with the best utilization of the relatively low sensitivity of in frared films As the sensitization of infrared black and white films barely extends beyond 1000 nm the red portion that is transmitted still makes a relevant contribution to the exposure That is why this filter is the preferred filter for pictorial photography on IR black and white film Its filter factor is 20 to 40 B W Infrared Filter 093 87 C nc 830 This B W Infrared Filter blocks the entire visible spectrum so to our eyes it looks completely opaque Unlike the infrared filter described above it makes pure infrared photographs possible without the visi ble red component Its transmission only begins to exceed 1 at 800 nm rising to 88 at 900 nm and remains that high far beyond the upper limit of sen sitization covered by infrared films This filter is used less frequently in pictorial photography because of the dramatic loss of effective ISO But in the scien tific field materials research and forensics the limita tion to a strictly infrared range is often important The filter factor is very dependent on the illumina tion and on the characteristics of the film B W Infrared Filter 099 16 oc 5501 The orange colored B W Infrared Filter 099 is the ideal filter for photography with infrared color film which is also referred to as False Color Film be cause of its charming abstract color re
57. hings become visible in a way and with a richness in details that is almost imperceptible to our bare eyes can be incredibly exciting Those who DENSES 47 believe that one needs specialized equipment to achieve that should take a closer look at B W E Close Up Lenses With these inexpensive accesso A ries that take up hardly any space in the gadget bag the range of applications especially of lenses with normal or short telephoto focal lengths can expanded dramatically Compared to extension tubes close up lenses can be more desirable not only because of their lower prices weights and volumes but also because of the clearly better image quality that can be achieved at reproduction ratios of up to approxi mately 1 2 5 The extremely strong B W Macro Lens can even be used to reproduce subjects the macro range at nearly 1 1 if a small reduction of sharpness in the corners of the frame is acceptable because of the very shallow depth of field the background most macro photographs is com pletely unsharp anyway Ww 1 zu wi at Lig Foto Peter Lebeda ipsi Lx ia i i The maximal reproduction o that be attained with close up lenses depend on the focal length and on the closest focus distance for which the lens can be set They also depend
58. hite film with B W Filter 093 amr Photographed on infrared color film without a filter Suppression of the blue cast with B W Filter 099 CCD sensors in digital cameras are very sensitive to infrared radiation which can generate false colors and blur This is why a filter layer on the sensor customarily sup presses However it is designed only to suppress enough of the infrared that would E E grossly affect color Sometimes additional filtration is needed in critical applications With the use of a B W Infrared Filter 092 or 093 the residual infrared sensitivity can ae be used to create interesting infrared pho tographs These will look similar to photo graphs taken conventional black and white Infrared film Because of the under exposure that would occur when using a manual exposure camera an increase in ex posure by at least one aperture stop is rec ommended plus automatic tonal value cor Color abstraction by means of an exposure toshop on infrared color film with B W Infrared Filter 099 B W Infrared Filter 092 89 B 695 The nearly opaque Infrared Filter 092 which looks dark purplish red when held in front of a light source blocks visible light up to 650 nm and passes only 5076 of the radiation just below 700 nm thus the dark red color From 730 nm to 2000 nm trans mission is greater than 9076 This makes photo
59. htness in propor tion to its density This is taken into account and corrected automatically by TTL exposure metering B W continues to maintain the cutting edge coating technology Optical and mechanical quality Because photographic filters are positioned in the image forming optical light path they should only have the labeled absorption characteristics and no other optical effects in order not to diminish picture quality The surfaces must be precisely plano parallel without bulges and tapering with perfect smooth ness irregularities lead to stray light and a soft focus effect their glass must be optically homogeneous and completely clear no striae or cloudiness and their surfaces must be as free of reflections as pos sible to avoid stray light and double ghost images The top priority of B W is the utilizing the highest possible optical quality glass as well as the highest quality filter mount The most modern manufacturing technology That is why professionals and photographic enthusi asts around the world insist on B W quality filters B W has been manufacturing filters for the most diverse applications for more than 50 years This extensive experience has produced a unique know how in glass and optical anti reflection coatings This in conjunction with Schott optical glasses state of the art finishing machines and continuous quality control lead to top products for the world market uil
60. ies of both filters in a single filter B W Polarizing Foil Polarizing filter foil placed in front of a light source produces polarized illumination With a second po larizing filter in front of the lens disturbing reflec tions on metallic on strongly curved or structured surfaces lime oil paintings can be eliminated Cau tion Do not let the foil become hotter than 70 C 158 F In other words keep the foil at safe distance from the bulb Available in square formats with 100 150 250 or 500 mm sizes appr 4 6 10 or 20 inches Better view with cementing Unlike some other polarizing filters B W Polarizing Filters do not consist of a plas tic polarizing foil loosely sandwiched be tween two protective glass discs Instead the polarizing foil is cemented to both glass discs for much better optical quality Even the tiniest surface irregularities on plastic polarizing foils which can not be produced as smoothly and as evenly as polished glass are evened out by this pro cess The number of reflective glass to air or foil to air surfaces is reduced from six to only two B W Polarizing Filters are distinguished by their higher light trans mission brilliance and yield excellent de tail even in the shadow areas This pre serves the full image quality of the lens Polarizers are multi talented Experienced photographers consider po larizing filters to be the most important filters Their ability to
61. ight at the light sources they are very long and they are most effec tive when they are not vertical and horizontal but at an angle of approximately 45 to the vertical axis B W Attachment 6x Cross Screen The star pattern produced by this screen is similar to that of the previous one except that it generates 6 beams from light sources and reflections at an angle of 60 to one another Here too the light rays ema nate right at the light sources whereas there is a small separation when Spectra attachments are used as descibed on the left hand side of this page B W Attachment 8x Cross Screen Like two 4 beam star screens superimposed at a rotational angle of 45 this star screen generates eight star beams Therefore as is the case with multi beam Spectra attachments there should only be a few light sources within the image area and the back ground should have large dark areas in order for the star beams to remain recognizable B W Star Effect Attachment Double Sunny A very fine diffraction grating generates a 16 star around every light source The fine beams are subtly divided into their spectral colors and they gradually dissipate towards their extremities This effect is especially dramatic in backlight situations in sunlight or with a different single but very bright light source within the image area STAR FILTERS SPECTRA FILTERS 42 43 Natural architectural information means of tru
62. ilter KB 15 80 A D The slightly denser KB 15 filter is recommended for daylight color reversal film with artificial light from the popular 60 to 100 watt halogen bulbs commonly used in lights aimed at the ceiling With weaker in candescent bulbs there will again be that pleasant warm tone for moody interior photographs Its filter factor is approximately 2 2 Color temperature and Mired A Color temperature of 5600 K Kelvin is assigned to the white light of the sun because the temperature of the surface of the sun is approximately 5600 Kelvin The Kelvin scale corresponds to the Cel sius scale C or degree centigrade ex cept that it does not begin with zero as the freezing temperature of water but with the absolute zero 273 16 C Because the incandescent filament of a halogen bulb must not reach the melt ing temperature of tungsten the most heat resistant metal which melts at 3653 K and which becomes soft before reaching that temperature halogen bulbs can only be used up to 3400 K At this temperature the blue component is much smaller than that of sunlight so that this light appears in the complementary color orange The incandescent filament of a conventional light bulb only reaches about 2700 its light appears even redder in other words more orange red Daylight color reversal films are bal anced for 5600 K and they record every color cast that our eyes perceive as m
63. in Blume mb Konrad Gotz kg Peter Lebeda pl Jos Schneider Optische Werke GmbH Thorsten Meywald tm Jos Schneider Optische Werke GmbH Page 2 pl 2 tm 2 Page 5 pl 1 tm 3 Page 8 tm 1 Page 10 tm 6 Pages 12 13 pl 1 Page 14 tm 7 Pages 16 17 tm 1 Page 18 tm 2 pl 1 Page 20 tm 6 Pages 24 25 kg 1 Page 26 tm 3 Page 28 pl 2 tm 2 Pages 30 31 mb 1 Page 32 pl 2 Page 34 pl 4 S 36 37 tm 1 Page 38 tm 3 Page 40 tm 7 Page 42 tm 4 Page 44 tm 5 Pages 46 47 pl 1 Page 48 pl 5 Pages 50 51 tm 1 Digital Design Borgers GmbH D 65510 H nstetten Wallrabenstein Druckerei Gras amp Jung GmbH amp Co KG D 55543 Bad Kreuznach MAGNIFIERS Optical perfection with a modern design Large lens diameter and ample diopter compensation permit comfortable effortless viewing as well as a large field of view for eyeglass wearers A sophisticated quick fastening device permits fast attachment or removal of the gently elastic neck strap The 3x 4x and 6x magnifiers are supplied with interchangeable opaque and transparent bases skirts for viewing reflection copy and transparencies Large field of view for 6x7 cm The generously proportioned optical system covers an area of 7x7 cm with outstanding imaging performance Ideal for examining roll films and large format sheet films Interchangeable bases skirts for viewing reflection copy or transparencies
64. ion too Lens hoods thus can significantly improve image quality Examples include a very bright background just outside of the angle of view a bright hazy or cloudy sky photographs on a white background or on a backlit background light table With a lens hood that is properly tailored to the angle of view a medium quality lens used in a situation with strong obliquely incoming light can possibly produce more brilliant pictorial results than a high grade far more expensive lens used without a lens hood That is so because the contrast achieved in the fine image structures is relevant to the impression of sharpness and that contrast can be significantly enhanced by the use of an appropriate lens hood or in other words the contrast can be significantly reduced by the avoidable flare Because the cost of a good lens hood is but a frac tion of the additional cost of a super lens nobody should neglect this very useful accessory This applies all the more to owners of expensive lenses whose performance capability is not nearly fully exploited without a proper lens hood Lens hoods also provide effective mechanical protection against raindrops accidental touching fingerprints reduce the contrast significantly and occasional strong im pacts on the exposed front element of a lens In this regard the collapsible lens hoods made of elastic rubber are particularly effective because of their impact absorbing properties A
65. ion of the two colored rays in the picture B W Attachment Spectra 8 8 directions With this special effects attachment eight colorful rays emanate from every strong light source like two crosses superimposed at a rotational angle of 45 This produces a romantic effect in nighttime city scenes such as streetlights automobile headlights spots in display windows or on stages and around all bright reflections B W Attachment Spectra 48 48 directions The 48 colorful rays produced by this attachment diverge by only 7 5 from one another and this den sity creates a circular pattern of multi colored light rays surrounding each light source Because of the large number of light rays the subject should contain only a few very bright light sources with a dark back ground in order to avoid an overly busy image B W Attachment Spectra 72 72 directions The increased concentration of 72 colorful rays with an angular separation of only 5 emphasizes the cir cular shape of the array of light rays even more Here it is even more important that there should only be very few dominating light sources preferably one two or three within the picture area and the background should be as simple as possible B W Attachment Spectra Spot The circular clear spot in the center of this attach ment leaves the central portion of the image largely free from spectral effects and surrounds it with col orful patterns of light rays aroun
66. is special green so the fluorescent light appears to us as nearly neutral in color However most color films are especially sensitive to those wavelengths and they react with a strong pronounced cast Photographers using color temperature meters for three color me tering simple meters that measure only two colors are not suitable for this purpose can also undertake the correct filtering with of a combination of LB and CC filters see pages 17 23 With this method they can also correct the light emitted by other types of fluorescent tubes such as Warm Tone Stan dard Light White Light etc But for hobby photogra phers who do not wish to make a large investment in such an instrument and who do not care to carry along a selection of LB and CC filters the B W F Day Filter is far less expensive and much more prac tical Its filter factor is approximately 2 B W UV Black Filter 403 vc 1 Not to be confused with UV blocking filters that photographers normally refer to as UV Filters this one passes UV A radiation 320 to 385 nm but blocks visible light and looks pitch black to our eyes It is used with appropriately sensitized films in such applications as ultraviolet reflection photography in forensics or in materials research but also as filters on UV emitters for fluorescence photography De pending on the illumination and on the film s sensiti zation its filter factor is in the range of 8 to 20 B W Special Filte
67. it is out of the refriger ator it is only good for a few months any so use it up quickly Because early black and white films did not render colors in the gray tones that corresponded to the brightness perception of human eyes the use of yellow and yellow green filters was simply indis TE FILI pensable 5 panchromatically sensitized black ee ee and white films no longer require such correction at least not in daylight In artificial light however m the increased red component can distort the rendi T an tion in gray tones in critical cases by rendering blue Iu e e tones too darkly and red tones too brightly This ER eee can be remedied by the use of a light blue filter with halogen light or a medium blue filter with in E iz candescent illumination Yellow and yellow green filters can bring more brilliance to landscape photographs and cre ig ate better differentiation of green tones in vegeta E tion Yellow and orange filters can magically trans ge form cloudlets into clouds and cloud formations od d dE and red filters can even raise them to dramatic y 25 thunderstorm strength or create moonlight effects very simple rule can be used to determine which filter should be
68. ity filters color filters for black and white photography and infrared filters For the Special Polarizing Filter according to see the adjacent page on the left rs for Rollei and Hasselblad bayonets Various lenses for Rollei and Hasselblad medium for mat cameras are equipped with bayonets for the at tachment of filters and lens hoods Bayonets have an advantage over threaded filters threads may also be provided by some of these lenses for quick attach ment and removal The line of B W filters also in cludes a series of color and polarizing filters in mounts that fit Rollei bayonets Il Ill and IV as well as Hasselblad bayonets 50 60 70 and 93 Original Zeiss Softar and Proxar attachments are distributed directly by Rollei and Hasselblad and are not available directly from rs for Astronomical Applications Filters are also used in astro photography and in vi sual astro observation They serve to enhance con trast for instance color and polarizing filters for observing and photographing the moon and the plan ets to emphasize or to attenuate certain spectral ranges for instance color and band filters for em phasizing faint gas nebulae in a sky that is polluted by city lights and to add neutral density filters for moon and only in combination with an additional lens filter or Herschel prism for sun observation and photography They also serve for improving im age sharpness and
69. lash illumination that would other wise produce neutral colors on color film There are two solutions for such problems 1 Strongly reduce the intensity of the flash by about two to three f stops so that there will only be a subtle fill in effect in the shadows and its differing color will not be conspicuous 2 Eliminate the flash altogeth er and expose only with available light Fill in shadows with a bouncer white cardboard sheet or foam plate if possible B W Fluorescent Light Filter 499 F Day This B W Special Filter eliminates the green cast that occurs when daylight type color film is in fluo rescent lighting Examples are interior photographs made in offices reception areas factory halls subway stations and swimming pool halls as well as night time photographs of office buildings whose windows would appear green because their interiors are usu ally illuminated with fluorescent tubes The abbrevia tion F Day stands for Fluorescent Light Daylight which reflects the fact that these filters are designed for the most commonly used type of fluorescent tube which emit light of a color that as mentioned above resembles daylight Because fluorescent tubes are not thermal radiators they do not produce a continuous spectrum like those of the sun and incan descent bulbs Instead they emit a sharply defined line spectrum that has high intensity spikes in the green region Our eyes barely perceive th
70. lash unit has too high a color temperature and thus an excessive blue compo nent Its filter factor is approximately 1 2 B W Conversion Filter 81 This B W conversion filter is also similar in effect to a Kodak Wratten filter and its strength of 27 Mired makes it comparable to the KR 3 conversion filter Like the 81 A it is recommended for color films that have an inherent reddish tone This filter is popular as it leads to very pleasing skin tones in portraits In addition the 81 B conversion filter is ideal for com pact flash units with color temperatures higher than 6000 K Its filter factor is approximately 1 2 20 21 COLOR CORRECTION B W C 05 B W C 10 B W C20 B W 40 B W M 20 B W M 40 B W Y 05 B W R 05 B W R 10 Bi B W 40 B W Color Cast Correction Filters CC Filters CC filters Color Correction or Color Compensa tion act specifically on relatively narrow bands of color That is why they do not come in two color variants bluish and reddish like conversion filters do Instead they come in the three primary additive colors and their three secondary colors which can be interpreted as the primary colors of subtractive mixing see below each color in practical density steps B W Color Cast Correction or CC Filters distinguish themselves from gelatin or acetate filter foils in that gel or acetate must be inserted in filter holders B W CC filters
71. lor of the light is not appropriate for the film But an absolutely faithful color rendition is not always desirable Using a filter not normally indicated by mired conversions can help create a mood While a portrait in the light from a standing lamp Grandma sitting in an armchair reading would have neutral colors when a KB 20 filter is used for removing the orange yellow color cast it would look like the scene had been illu minated by a halogen stage spotlight In order to preserve the splendor of a red evening glow no filter at all could be used In order not to drench the lamplight portrait in orange colored light yet not make it appear as cold a remnant of warmth might be retained This can be accomplished by under filtering for in stance by using a KB 12 filter instead of a KB 20 filter A good guide is 2 3 of the neutral filtering B W Conversion Filter 81 This conversion filter has an effect similar to that of Kodak Wratten 81 A gelatine filter Its strength of 18 Mired makes it approximately similar to the KR 1 5 conversion filter except that it is less reddish as it absorbs a little bit red It can be used like the KR 1 5 filter especially with films that tend to a reddish rendition inherent to their emulsion or to the devel oping process The 81 A conversion filter is also ideal for landscape photographs at noontime and for flash exposures on daylight reversal film when the light emitted by a compact f
72. lter on the lens number 37 x 0 75 8i 35 5 x 0 5 8f 105 x 1 0 100 x 0 75 0 100 x 1 0 00 49 x 0 75 58 x 0 75 25c 55 x 0 75 26a 82 x 0 75 77 x 0 75 101 52 x 0 75 28 72 x 0 75 100 48 x 0 75 77 x 0 75 Rollei Bayonet VI 0c 46 x 0 75 9e 72 x 0 75 45 0 5 9f 67 x 0 75 1 43 x 0 75 9g 62 x 0 75 1b 41 0 5 9h 40 5 x 0 5 9 i 72 x 0 75 Rollei Bayonet VI Ob 37 x 0 75 9m 77 x 0 75 21 36 5 x 05 9k is 35 5 x 0 5 9 62 x 0 75 1 d 58 x 0 75 48 0 75 55 0 75 26 b 67 x 0 75 Hasselblad Bayonet 60 46 0 75 55 x 0 75 26 c Rollei Bayonet VI 0a 43 x 0 75 11b 62 x 0 75 2 41 0 5 11 60 x 0 75 2 40 5 x 0 5 11 58 x 0 75 2b 37 x 0 75 11 40 5x05 39x05 15 PF 35 5 x 0 5 15a 49 x 0 75 2 f 39 x 0 5 30 5 x 0 5 16a 62 x 0 75 67 x 0 75 22 60 x 0 75 3e 37 x 0 75 35 5 x 0 5 17 d 58 x 0 75 3 30 5 x 0 5 17c 55 x 0 75 3a 30 x 0 75 16c 52 x 0 75 3b 28 x 0 75 17 b i 305x05 28x075 17a 60 x 0 75 55 x 0 75 4b 58 x 0 75 Hasselblad Bayonet 50 55 0 75 5 52 x 0 75 5b 49 x 0 75 5 43 0 75 55 40 5 x 0 5 5h 39 x 0 5 B W Front Lens Snap Cap 310 two opposing spring loaded keys together and lift the cap off Available in the following sizes 46 E 48 E 49 E 52 E 55 E 58 E 62 E 72 E and 77 E On Front Lens Cap 300 thread Available for lenses or filters with the follow ing front rim diameters 27 30 32 37 42 51 54 57 60 65 and 70 mm B W SLIM Front Lens Cap 305 whe
73. mixing is called subtractive color mixing If we once again mix red and green but in the subtrac tive manner just mentioned for instance with wa tercolors the resulting mixture will not be brighter than each individual color and yellow as it was with the spotlights but darker and brown black The effect of color filters Colored filter glass absorbs a certain portion of its complementary color from the incoming light and lets the rest pass through A yellow photographic filter for example absorbs part of the blue compo nent of light and lets the rest which is a mixture of all the other colors appear as yellowish For certain technical applications however there are special yellow filters narrow band pass filters that ab sorb not only a portion of the blue light but all col ors other than yellow When colored light instead of white light passes through a yellow filter for black and white photography a portion of the blue com ponent of the colorful mixture is absorbed and its brightness is altered Photographed through a yellow filter a blue sky is rendered noticeably darker the gray values of green foliage and grass with low blue component are hardly changed at all yellow or or ange colored blossoms without a blue component do not lose any brightness so that they appear lighter in relation to other colors that have been re produced in darker shades A filter in front of a lens therefore reduces the overall brig
74. n make a con tribution to the soft focus effect that is at least equal to that of the finely coated veil of unsharpness It s better to over expose In descriptions of the effects of soft focus attachments reference is frequently made to flare light fringes or halos That implies that the subject is bathed in light The friendly effect of such soft focus pho tographs also has something to do with our fondness for just the right amount of pleasing light That amount of light can only appear authentic if the picture s light colored portions are really bright That in turn means that the original exposure should not be too dark but preferably a bit over by approximately 1 3 to 1 2 of an ap erture stop The Softspot attachment consists of a clear circular opening in the center surrounded by a structured surface that coats the outer portions of the image with a whitening unsharp softness in a vignette like fashion the center of the image is clearly emphasized and surrounded by a wide frame At large apertures small f stop number the transition from sharpness to whitened unsharpness is very gradual whereas it is almost abrupt when the lens is stopped down It is advisable to use the preview lever on cameras that are equipped with one to determine the optimal aperture for this effect prior to the exposure SOFT FOCUS ATTACHMENTS 40 41 bin d d 2 Arched spectral light ribbons with Spectra Spot at the li
75. n the diameter of the front rim of the lens is slightly greater than that of the SLIM filter so that a normal lens cap could not be slipped on completely Available for the following SLIM filter mounts 49 E 52 E 55 E 58 E 60 E 62 E 67 E 72 E 77 E and 82 E or for the corresponding outer filter diameters 52 55 58 61 62 65 70 75 80 and 85 mm B W Rear Lens Caps 330 to 335 M 42 thread 335 B W Camera Body Covers 320 to 325 corresponding tele converters provided their opti cal systems are sufficiently recessed in their mounts Protective lens cap with two spring loaded plastic claws opposite each other that engage the female filter thread of the lens or the front thread of an at tached filter That permits a fast and secure seating of the lens cap without the need of time consuming screwing To remove the Snap Cap simply press the Protective lens cap made of flexible plastic material that slips over the outer front rim of the lens or the rim of an attached filter It may also be used for some binoculars It remains in place by means of friction of the slip proof plastic material This lens cap can also be used on an attached filter that has no inner front A flatter slip on lens cap made of flexible plastic material It has all the features of the previously de scribed slip on lens cap except for its thickness Its thickness is tailored to that of the B W SLIM filter mounts but it can also be used on
76. nity 102 ND 0 6 2 f stops Linear Polarizing Filter according to uncoated thickness 3 5 mm 0 2 mm Conversion Filter KB 1 5 82 A Conversion Filter KR 1 5 1 A Conversion Filter KR 12 85 Fluorescent Light Filter 499 F Day Yellow Filter Light 021 2 E Red Orange Filter 041 22 Yellow Green Filter 060 11 Red Filter Dark 091 29 Grey Graduated Filters uncoated 3 mm thick Sizes 75 75 mm 100x100 mm and 100x150 mm Graduated Filter Gray 50 501 Graduated Filter Gray 25 502 Graduated Filter Orange 524 Graduated Filter Violet 543 Graduated Filter Tabac 550 Graduated Filter Yellow Green 560 Graduated Filter Green 561 Graduated Filter Purple 585 Graduated Filter Red 590 Filters marked with an asterisc are available on request Matching Containers 75 75 mm Filters Nylon Filter Case Size E 1 Plastic Filter Box Size D 100x100 mm Filters Nylon Filter Case Size E 2 Plastic Filter Box Size E B W Round Filters for the 28 mm f 2 8 PC lens B W Filte B W Filte A special lens hood that accepts interchangeable 74 mm diameter glass filter discs see page 53 was designed for the 28 mm 2 8 Schneider PC Super Angulon This lens has an extremely large angle of view and shift capability utilized for the correction of converging lines The glass filter discs are available as UV blocking filters Skylight filters LB and CC fil ters Neutral Dens
77. ns Filters make it pos sible to achieve photographs that simply could not be made without them and many of them could not be accomplished with subsequent digital image manipulation The same applies to direct digital photography B W therefore provides digital imag ing filters in diameters and designs suitable for lens es on most current digital cameras and camcorders In order to deliver optimal image quality and to safeguard the high demands of lens camera manu facturers B W glass filters are manufactured virtu ally exclusively from glass supplied by the German Schott Group In Bad Kreuznach the most modern fabrication ma chines produce highly precise filters in an impressive variety of types and diameters Quality controls are integrated at all key stages of the production pro cess and a final inspection of every individual filter ensures the renowned high B W quality standard At B W our commitment to our guarantee and service are taken seriously Continuous improve ments and new developments enable users to achieve their best possible images By comparison a cheap filter can reduce the imaging performance of a high quality lens quite dramatically Therefore consider the quality of a filter as seriously as you would consider the choice of your lenses look for the B W brand because the quality of the image depends upon what is in front of the lens m a I ag E B 3
78. nt of light from the sky requires the stronger filtration of a KR 3 Conversion Filter for rendition with neutral colors B W Conversion Filter 1 5 Skylight This most delicate reddish yellow conversion filter absorbs violet and some blue plus a minimal amount of green but it passes yellow and red undiminished the color of the light becomes warmer by 15 Mired That is mostly the optimal amount for correcting the light blue cast in the shadows under a blue sky It also absorbs UV radiation and hence it provides better sharpness With color films and or developing pro cesses that generally yield results that are too cool this filter can be kept on the lens at all times With this filter skin tones in particular will be rendered more naturally Its filter factor is approximately 1 1 B W Conversion Filter KR 3 81 C 600 With approximately twice the strength of the KR 1 5 the KR 3 filter reduces blue and green Even the strong blue cast of a high standing sun in a cloudless azure blue sky in regions with especially clear air or the haze in distant views is removed very effectively This filter also blocks disturbing UV radiation com pletely Its filter factor is approximately 1 2 B W Conversion Filter KR 6 x 81 EF With double the strength of the KR 3 the KR 6 filter leads to neutral color rendition in strong haze or in mountains above 2500 m 8200 feet when transpar encies are not to show blue mou
79. ntains which can also be attractive depending on the individual case It should not be used for photographs of typically foggy landscapes Another field of application would be interior photographs on daylight reversal film when only blue light from the sky and no direct sun light is coming through the window and no fill in flash is being used In combination with tungsten re versal film the KR 6 filter imparts the warmth of normal incandescent bulbs to the light emitted by halogen bulbs which would appear neutral white without a filter Its filter factor is approximately 1 4 B W Conversion Filter KR 12 85 This reddish brown filter allows the use of a tung sten balanced film in daylight without a strong blue cast It effectively absorbs the excess of daylight blue that is otherwise superimposed on all the colors But the KR 12 filter is useful not only as a savior in cases of need or for making good use of an otherwise useless remnant of film because it can also be used effectively for overcoming extreme contrasts that are greater than a daylight reversal film can handle A reversal film balanced for tungsten light has a flatter gradation curve adding a possible high contrast con trol Its filter factor is approximately 2 CONVERSION FILTERS LB FILTERS What is under correction For neutral color rendition one of the conversion filters listed in the adjacent descriptions is recommended when the co
80. o 58 mm thus conserving space in the gadget bag B W Metal Lens Hood 950 A good looking and sturdy lens hood for standard lenses made of black an odized aluminum with light absorbing flat black ribs on the inside Space sav ing short design B W Metal Wide Angle Lens Hood 970 shorter sturdy lens hood for wide angle lenses with angles of view up to more than 70 made of black anod ized aluminum with light absorbing flat black ribs on the inside B W Metal Lens Hood for the 28 mm f 2 8 PC lens Special wide angle lens hood for the Schneider 28 mm f 2 8 PC Super An gulon lens on which only this particu lar lens hood can be used also see B W Round Filters Page 59 B W Metal Telephoto Lens Hood 960 A sturdy lens hood for all telephoto lenses is made of black anodized alu minum with light absorbing flat black ribs on the inside Thanks to its large length it is very effective Lens hoods obstruct light rays from outside the im aging angle of view that strike the lens yet do not contribute anything to the structure of the image Hoods prevent unnecessary light rays from being reflected diffusely or directly by lens surfaces rims inside the lens mount and even inside der camera body Because such stray light especially light rays entering obliquely from the front can veil the image or super impose light spots and ghost images it can lower contrast This results in a loss of definit
81. oftly And telephoto lenses are not appropriate ei ther because they no longer separate the picture portions formed by the prism at tachments at all imaging them nearly on top of each other instead similar to an accidental multiple exposure The optimal positioning of the partial images and the ideal aperture can be judged by rotating the mount of the at tachment and using the preview lever or button When used with video cameras eye catching effects can be achieved by rotating the prism attachment during the exposure and or zooming B W Close up Prism The close up prism attachment has the effect of a 7 diopter close up and because its two halves are two wedges whose thickness increases towards the center it produces two images Like the other prism attachments it is recommended for use with a normal lens It produces a sharp image at a distance of approximately 14 cm 51 2 inches with the lens focused at infinity The reproduction ratio is slightly greater than 1 3 With the lens focused at the closest distance the subject distance can be reduced to ap proximately 11 cm 43 8 inches and the reproduction ratio will be increased to nearly 1 2 The two identical images can be arranged side by side or above one another or even adjacent diagonally depending on the rotational orientation of the attachment PRISMS TRICK FILTERS 44 45 To explore certain domains photographically to make t
82. olarized light depending on the rota tion of the filter Thus clear view is made possible through plates of glass of goldfish below the sur face of the water or of writing or pictures behind a glossy layer of lacquer Every object outdoors reflects light from the sky more or less diffusely and largely polarized some objects such as green plants and red roof tiles are covered by a bluish gray veil that can make them appear pale and dirty B W Polarizing Filters can remove this polarized veil and thus increase the saturation of the true color Because the blue light from the sky especially at an angle approximately perpendicular to the sun 15 strongly polarized polarizing filter can be used to render the sky with more saturated color so that white clouds will stand out more dramatically Using a polarizer for black and white film reflections can be accentuat reduced p can higher i image contrast Le a I 4 ond E d v qur M ee o a FE j E i 4 m r ales 1 _ E 1 a oy A PEL imm a pim QR ez POL X EC MS OHK Reflection and blue haze without a polarizing filter Reflection with the blue cast removed by B W Polarizing Filter a A polarizing filter makes the clouds stand out but on this very wide
83. or means that the exposure time has to be doubled to compensate for the loss of light that results from the effect of the filter The filter factor always applies to the exposure time or shut ter speed not to the aperture value However because the shutter speeds on most cam eras can only be changed in full exposure steps in accordance with factors 2 4 8 16 32 and filter factors often have uneven intermediate values in practice corrections are seldom made by means of the shutter speed but by the aperture The table below shows what filter factor corre sponds to how many aperture stops Intermediate values can be rounded up or down because small deviations are absorbed by the exposure latitude of the film without a noticeable effect on the picture Corrections can also be made with shutter speeds and f stops provided the correction is shared by both parameters 15 20 30 40 Factor 4 5678 10 f stops FILTER FAKTORS MIRED IMPRINT Mired diagram Daylight Film Tungsten Film Mired and Decamired 10 Mired are units used for describing the corrective effect of LB or conversion filters pages 18 to 21 These units are convenient because identical differences between Kelvin values like those of light and film require much smaller cor rections at high color temperatures than they do at low color temperatures whereas identical Mired dif ferences always correspond to identical effects
84. other filters Therefore this lens cap is especially advantageous Protective cover for the camera side rear bayonet or thread of the lens Available for the following bayo net mounts Canon FD 330 Minolta MD 331 Nikon 332 Olympus OM 333 Pentax K 334 and Protective covers for the bayonet or thread lens mounts on camera bodies Available for SLR cameras with the following lens mounts Canon FD 320 Minolta MD 321 Nikon 322 Olympus OM 323 Pentax K 324 and for M 42 thread mounts These covers can also be used as front protective covers on MEIST Protect your lens with a cap Quite a few photographers assume that their lenses are adequately protected against dust dirt and damage inside their gadget bags and therefore they dispense with the protective lens caps because they think that the latter are superfluous The very same photographers should not be surprised that every few weeks they have to use a camel hair brush an air bulb and a cleaning cloth to remove the dust deposits lint and fingerprints that accumulated since the previous cleaning But those who take the precaution of attaching protective covers to all the lenses in their gadget bags probably will only have to use a brush and a cleaning cloth on those lenses twice a year before and after the great vacation trip unless an unusual situation makes an unsched uled cleaning necessary It is not a matter of avoiding extra work or g
85. p to 62 E It easily fits in any gadget bag for instance readily accessible in a front compartment It has proven to be a convenient and safe carrier for the most important filters and attachments B W Nylon Fabric Filter Pouches E 1 E 2 and E 3 These filter pouches are made of padded water and abrasion resisting Nylon fabric with practical Velcro closures and a white space for identification They are available in the following sizes 11 5x11 5 cm for filters up to 77 E E2 14 5 14 5 for filters up to 105 E 20 0x200cm for filters greater than 105 E B W Collapsible Lens Hood 900 This collapsible lens hood is made of high grade rubber and its angle of view is tailored to standard or short tele photo lenses Its inner ribbed surface enhances the light absorbing effect of the flat black surface In the collapsed state for example in filter thread sizes up to 77 mm it increases the length of a lens by approximately 10 mm B W Collapsible Wide Angle Lens Hood 920 This collapsible lens hood is designed for wide angle zoom lenses with an gles of view up to 70 With shortest focal lengths it should be used without filters in order to avoid vignetting B W Collapsible Telephoto Lens Hood 930 In spite of its large effective length this collapsible hood for telephoto lenses only increases the length of a lens by appr 26 mm about 1 inch in the case of filter thread sizes up t
86. production It blocks large portions of short wave radiation up to 520 nm blue blue green and reaches its full trans mission near 600 nm which it retains far beyond the sensitization range of these films This avoids the blue cast that is caused by the heightened sensitivity in this spectral range and it leads to a better differ entiation of colors The charm of these infrared color photographs is partly due to the orange to red rendi tion of green vegetation which is due in turn to the high infrared reflectivity of the chlorophyll in plants The filter factor is highly dependent on the film and on the degree of infrared reflection of the subject Infrared Filters are also available on special order with Schott glass types OG 590 RG 610 RG 630 RG 645 RG 665 RG 715 RG 780 or RG 9 MEI INFRARED FILTERS Invisible infrared radiation The spectral range that is visible to the human eye ends at a wavelength of ap proximately 750 nm This is where infra red radiation begins only certain birds can see portions of infrared radiation that better penetrates haze Most films parallel the spectral response of our eyes But there are special infrared sensitive films for color and black and white pho 28 tographs which depending on their sensi tization react to 850 nm 900 nm or 29 nearly 1000 nm radiation Like other films these are also very sensitive to visi ble light If we wish to imag
87. r The num ber of these vibrations per second on the order of 600 000 000 000 000 is just as unimaginable as the spreading speed of light nearly 300 000 km or 186 411 miles per second We are able to visualize the wavelengths of these vibrations circa 380 nm to 750 nm nanometers or approximately 1 2000 of a millimeter We perceive the different wavelengths as different colors the shortest ones as violet then blue green yellow orange red and the longest wave lengths as purple red And white light is nothing more than an even mixture of all these colors in the same proportion as we receive it from the sun properties define the color of an object An object that is struck by light can reflect that light nearly completely partially or nearly not at all If it reflects all the wavelengths i e colors uniformly and nearly completely the object appears to us as white If it reflects them uniformly but only partially the object will appear to us as gray under white light and when it reflects hardly anything we perceive it as being black Most objects however do not reflect all colors uniformly some of them are reflected more strongly others less strongly or not at all The sur face of the object will then no longer appear to us as being white or neutral gray but colored usually in a mixed color Red Yellow Magenta Green Blue Cyan Additive and subtractive color mixig A spread of th
88. r films react quite differently they faith fully register every deviation of color be it ever so small from the norm as determined by their color sensitization Daylight films want to see spectromatically correct white light with a color temperature of 5600 K if they are to reproduce the original colors of the subject faithfully Films bal anced for artificial light Tungsten require M K 4 light typically incandescent for that purpose But i 5 B W filters comprise an extensive line of cor ction filters optimal for every situation tailoring the film This includes the correction of color casts that may result from reflections of colored walls from reciprocity failure with long exposure Y or from irregular processing conditions E _ 12 B W Tip Compute with Mired Color temperatures in Kelvin must not be numerically added or subtracted because they do not behave linearly Sums or differ ences calculated in this manner lead to false results With a simple formula however Kelvin values can be converted into Mired values which can then be added or sub tracted from the Mired values of the filters Mired value 1000000 Kelvin value Halogen illumination with daylight film Neutralized with Conversion Filter KB 12 Kelvin value 1000000 Mired value For 5600 K daylight color film the Mired value is 1000000 5600 178 6 For 300
89. rade electronic control units for precise positioning speed power and pressure controls in mechanical engineering LIGHT COLOR FILTER EFFECTS Light wavelength and color Reflection Light is an electromagnetic phenomenon with many facets It travels with unimaginable high speed and it transports energy even through completely empty space Light can traverse transparent materials and in the process be diverted from its straight path be reflected diffusely or directly be absorbed and blend of frequencies can be altered through absorp tion yielding a new balance of color Light has fasci nated generations of physicists and enabled astrono mers to discover the secrets of outer space at dis tances that are far beyond our reach and our capac ity of imagination Light is the medium with which we create ourselves a picture The nature of light is so complex that we require two different physical models in order to explain its qualities that sometimes appear to be contradictory When reacting with matter light can behave as if it consisted of tiny particles photons that zip through space and which upon impact produce a photo effect reaction which is the basis of the function of an exposure meter or digital camera sen sor However it also behaves like a wave phenome non that spreads in space in a spherical manner con sisting of interwoven electrical and magnetic fields that vibrate at right angles to each othe
90. ray For example the red tiles on a roof and the green of nearby vegetation But this can be man aged The color of the filter and its relat ed colors are transmitted virtually undi minished whereas their complementary colors are attenuated so that they will appear darker in the photograph When that loss of brightness is compensated in accordance with the filter factor the re sult will be a correctly exposed picture that shows the colors related to the color of the filter as lighter shades of gray Complementary colors those that are opposite each other in the color star on page 4 will abpear as darker tones Filters with TTL metering Today nearly all SLR cameras feature TTL Through the Lens exposure metering which means through an attached filter as well This metering method takes into account the loss of light absorbed by the filter so that filter factors usually need not be applied However when the expo sure is measured with a separate expo sure meter then the filter factor has to be taken into consideration Still with darker filters very dense colors exposure bracketing of 1 2 to 1 aperture stops is recommended even with TTL exposure metering because the spectral sensitivity of the metering cell can be significantly different from that of the film B W Yellow Green Filter 060 11 cc 01 60 This filter has an effect similar to that of the medium yellow filter but it also darkens red colors Clo
91. re for photographers using AF reflex cameras The light diverted from its regular direction by the mini lenses coats the image with a diffuse halo of light for a delightful softness This soft focus attach ment is as ideal for feminine portraits especially with highlights in blond hair You can also use this attach ment to create dreamy landscapes B W Soft Focus Attachment Soft Image Subject contours flow markedly softer with the Soft Image attachment on the lens than they do with the B W Soft Pro Prominent halos form around light sources and reflections and bright parts of the subject acquire a noticeable veil of light This effect is maintained even when the lens is stopped down It is recommended for portraits and for backlit situations however it may be too soft for some landscapes SF Attachments Original Zeiss Softar 1 and 2 B W Fog This soft focus attachment has a large number of mini lenses of varying sizes distributed on its surface in a random pattern which deliberately defocuses the light that is passing through This creates a soft unsharp image around a sharp core image which is advantageous for reliable manual or automatic focus ing The soft focus effect is largely independent of the chosen aperture setting so that the depth of field can be controlled for the most part with only very modest concern for the degree of the soft focus effect For a delicate soft focus effect there is
92. rease until the even distribution is reached that is necessary for correct color rendition on daylight type color reversal films Reddish conver sion filters on the other hand absorb light in the short wavelength portion of the spectrum In other words little green more yellow and even more blue so that for instance white daylight will be changed to have a spectral energy distri bution like that of red rich tungsten light CC or color correcting filters on the other hand act selectively on narrow ranges of color While they do not correct overall color temperature they do specifi cally eliminate the mostly monochromatic color deviations caused by colored reflec tions reciprocity failure with long time exposures and color casts that are inher ent to certain emulsions and developing processes These filters can even be used to eliminate the strongly different color casts of different types of fluorescent tubes Professional photographers use 3 color color temperature meters that not only indicate Kelvin and Mired values but necessary CC filter values as well What photographer wouldn t love to leave the ten path and create pictures that stand out fasci nate perhaps even take one s breath away To show objects landscapes as no eye would see them in FILTERS nature is an irresistible challenge A large selection of B W Special Filters can help you to take on this chall
93. rection unsharp masking This method cannot efficiently duplicate the brilliance and detailed sharpness that a UV IR blocking filter in front of the lens would have preserved If reflections on a pane of glass block the view of things behind it even the most sophisticated image manipulation program cannot magically recreate information that s been lost whereas a polarizing filter would have eliminated most of the reflections And enhancing filters add specific enhancements that are unique and not duplicated in post production imaging control The mount sizes and the design of fil ters from B W are tailored specifically to digital cameras and camcorders Their exterior chrome fin ish harmonizes perfectly with the trendy light colors of digital cameras and their optical quality is tailored to the high resolution digital lenses Check to see if the digital camera that you are considering has a filter thread If so you will later be able to use high grade filters to make corrections and to add creative effects oak BE 880 a Iu xe 6 UV Skylight and Protection Filters 8 Neutral Density Filters 10 Polarizing Filters and Redhancers 12 Correction Filters LB CC 16 Special Filters F Day UV IR 24 Filters for black and white photography 30 Special Effect Filters Soft Focus Filters Prisms 36 Close up Lenses 46 Accessories 50 Specifications Types of mounts 56 General overview of all filter
94. reduce or eliminate reflections is probably their best known feature but it is not the only one They enhance the color purity of the subject increased color saturation by blocking the blue veil of light from the sky They increase the contrast in black and white photographs reduce haze and make white clouds stand out dramatically from an intensely blue sky When the filter is rotated by 90 from its normal reflection reducing position it can even appear to increase the relative intensity of reflec tions on water glass lacquer and plastic materials up to a factor of 2 B W Redhancer 491 The B W Redhancer made from didymium glass is a filter with very special transmission characteristics Designed to strengthen the reddish components of orange near red or brown subjects it is very popular for use in nature and landscape photography It is particularly effective in conjunction with a polarizing filter controlling a potentially bluish gray veil and for increasing color saturation e g to capture fabulously vivid scenery during the colorful autumn season The use of color reversal film is recommended because the automatic correction applied by printers to color negatives can erroneously interpret the desired ef fect as a color cast and reduce it by filtering it out POLARIZERS REDHANCER 14 15 Ar arr ini S d zn H ini ae et T
95. reduced range of filter types see page 59 only oversized filter M 86 x 1 0 on p 64 can be used Od 863 UU gc 40j HL OLX amp on request 50 01 X0 S6 W 01 X098 W 00000 00000 OO OO OO OO OO OO OO OO OO OO 3 3 OO O OO OO O OO OO 9900090009000 0000000 O OJOJOO 000 _ 6 0 0 C8 W 6 0 X 0 W EN 9 e 9 OIOIOIOOO CED lt 0 099 W s 0x009W CHED 5 0 085 W 0050 Gamm ssox0ssw OIOIOIOIOOO O0 9
96. ree illumi nation of the picture is very helpful For the evaluation of transparencies or nega tives on a light table however the magni fier base should be opaque and matte black on the inside Therefore the ideal magnifiers are supplied with interchangeable bases skirts for both types of viewing erke GmbH 3 Bad Kreuznach 11 25 160 13 02 eiderkreuznach com neiderkreuznach com
97. rrespondingly larger filter glass The advantage of this design is that it offers a larger window so that the image periphery will not be obstructed meaning that there will be no vi gnetting darkening of the corners of the image For extreme wide angle lenses with angles of view of 110 or even 120 especially those with a generous image circle for adjustable large format cameras these filters are a must Because wide angle lenses by nature already have the unavoidable brightness reduction near their edges due to the laws of physics the cos law additional vignetting caused by thick filter mounts would be all the more conspicuous Oversized filters which are available in the most popular sizes see the tables on pages 62 to 64 have a very flat mount and should be used without a lens hood because the latter may still introduce some vignetting B W Polarizing Filters according to Kasemann Polarizing filters are thicker because they have two glass discs with a polarizing foil cemented between them so that with normal ring thickness they may shade the corners of the image when used on wide angle lenses B W polarizing filters which are 5 mm thick are also available in the Kasemann version and they are suitable for vignetting free use on most wide angle lenses In the case of lenses for 35 mm cameras they can be used with focal lengths down to 28 mm and often even down to 24 mm For wide angle lenses with an ev
98. rs with Schott Glass types BG 18 BG 12 BG 38 BG 39 and VG 9 are available on special order Upon request they are also available with other types of Schott Glass This sharp cutting nearly colorless B W filter blocks UV radiation up to the limit of visible light It is used in ultraviolet fluorescence photography for the pre vention of unsharpness caused by the intense UV il lumination which is due to chromatic aberration in the UV range It can also prevent the fluorescence that may occur in the cement between lens ele ments Because of the usually rather colorful fluo rescent subjects the delicate yellow cast in color photographs is negligible Its filter factor is 1 B W UV Blocking Filter 420 2 A 66 420 This even more stringent UV blocking filter behaves like the filter 415 described above except that its filtering slope completely blocks the UV radiation all the way into the visible violet region As a result it has a noticeably yellow tint It is used for fluores cence photography on black and white film where it is even more effective Its filter factor is 1 2 B W Digital UV IR Blocking Filter 486 This Interference Filter has a completely color less glass carrier coated with a number of extremely thin partially reflecting layers with precisely com puted thicknesses similar to MC coating The Filter 486 does not block by means of absorption but by interference of
99. s With the trend for keeping dimensions and weight of their lenses as compact as possible many lens manu facturers are supplying their wide angle lenses with filter thread diameters that are so tight that a filter with normal thickness might vignette To solve that problem B W has introduced the thin ner line of B W SLIM wide angle filters without a front thread that are a mere 3 mm thick designed for super wide angle lenses that are prone to vi gnetting Because SLIM polarizing filters have not one but two glass discs with the polarizing foil ce mented between them they are 5 mm thick In most cases SLIM filters permit exposures even with extreme wide angle lenses with focal lengths as short as 17 mm without vignetting caused by the fil ter mount B W SLIM wide angle filters distinguish themselves from filters available from other manufacturers by their outstanding mechanical execution with retain ing rings that guarantee an absolute lasting rigid as sembly The unique B W Polarizing Filters according to Kasemann are now available in super flat 5 mm thick SLIM mounts for vignetting free wide angle photographs B W Wide Angle Filters with oversized mounts Compared to normal filter mounts that have about the same outer diameter as the lens mounts the di ameter of the front portion of an oversized filter mount is much larger than its thread that is screwed into the lens and it has a co
100. s 415 420 Digital UV IR Blocking Filter 486 Infrared Blocking Filter 489 29 Infrared Filters 092 093 099 33 35 Filters for black and white film 021 022 023 040 041 Filters for black and white film 060 061 090 091 Filters for black and white film 080 081 39 41 Grad Filters 501 502 524 543 550 560 561 581 585 590 Soft focus attachment Soft Pro Soft focus attachment Soft Image OJOO 90 0 90 0 0 0 OjOJO 0G QjG J OOJOO 090 0 0 0 0 0 OJjOO 0G9O0 0 0 0 0 0 OjOJjO 0 355 05 OJOO 90 0 90 0 0 0 OJOO 90 0 60 0 0 0 Soft focus attachment Original Zeiss Softar 1 2 Fog attachments Fog 1 2 Softspot 43 45 Special effects attachments Spectra 2 8 48 72 Spectra Spot Cross Screens 4x 6x 8x Star effect attachm Double Sunny Multi Image Prisms 3x 5x 6x Parallel Pr 3x 6x Close up Pr 0 370 0 5 49 Clo
101. s NL 1 NL 2 NL 3 NL 4 NL 5 0000 Filter factors The transmission curves on the preceding spread on the pages 60 and 61 show the result of absorption or reflection the latter in the case of interference fil ters of different portions of the incoming light that vary in accordance with their wavelengths In other words a filter doesn t add light but rather withholds light from the lens A yellow filter for example does not add the color yellow as the name might suggest instead it attenuates or blocks the complementary color blue This removal of portions of light also results in the reduction of the amount of illumination that reaches the film which has to be compensated by means of an increase in exposure With TTL through the lens exposure metering this is taken into account automatically so that in most cases the photogra pher does not need to compensate any further However not every camera offers TTL metering Also TTL may not be accurate when strong or nar row pass filters are being used such as orange filters and dense red filters Furthermore TTL is highly unreliable with UV and infrared filters because the spectral sensitivity of the metering cells does not match that of the films with sufficient accuracy That is the reason why the descriptions of B W fil ters always include a filter factor by which the expo sures of average subjects have to be increased Thus a 2x filter fact
102. se up Lenses NL f NL 2 NL 3 NL 4 Close up Lens NL 5 Macro Lens 53 Collapsible Lens Hood 900 Collapsible Wide Angle Lens Hood 920 Collapsible Telephoto Lens Hood 930 Metal Lens Hood 950 Metal Wide Angle Lens Hood 970 Metal Lens Hood for 28 mm f 2 8 PC Super Angulon lens 111 OOOO00000000000000 0 00000 240 111111 ooeoeoooooo0000000 00000 wnoxor 21 11 OOOO00000000000000 0000 OOO0O0000000 200020000 00 000 00 0 comm _ 0009 60 00 0 00 09029 020209 0090 000 000 0 390 05 amu _ 9 00000 Matoxos Metal Telephoto Lens Hood 960 N N 4 62 OO X OO 54931 555 GLX GL 5103 5521 8 0 X 8b 579311 9435 S O X lt 87 osy v 6 6 Solas 63 0 pejqjessey 09 0 pe qiesser 9 9 rejoy OO OO partially a special Hasselblad adapter ring is required on request
103. sizes 62 B W UV Filter UV 010 Ice 375 This UV Filter blocks the invisible UV component of light from the sky which can cause blur and to which many color films react with a blue cast These filters should be called UV Blocking Filters because there are filters for technical applications that pass UV diation and block all the other wavelengths Never theless the short term UV Filter has become es tablished among photographers UV Filters are ideal for photography in high altitudes in the mountains by the sea and in regions with very clean air The pictures gain brilliance and disturbing blue casts are avoided Because the glass is colorless color rendi tion is not altered aside from the elimination of the unwanted blue cast and no increase in exposure is required That makes a UV Filter very suitable as protection of the front element of the taking lens against dust flying sand sea water spray and the like and it can be kept on the lens at all times It is recom mended for analog color and black and white as well as digital photography UV Filters from B W also available in SLIM mounts for wide angle photog raphy without vignetting Other UV blocking filters with special characteristics please find on page 27 B W Skylight Filter KR 1 5 1 A D Gs This filter also blocks UV radiation however it also has a delicate reddish yellow tone designed to co
104. the Softar 1 and for a more pronounced soft focus ef fect there is the Softar 2 attachment Attachments Fog 1 and Fog 2 The effect of the Fog 1 and Fog 2 attachments is quite different from that of the soft focus attachments as descibed above The subject appears to be behind a delicate bright veil of fog which unlike the effect created in corresponding pictures by soft focus at tachments also noticeably lightens large dark por tions of the picture All colors are strongly whitened and desaturated By slightly over exposing by ap proximately half an aperture stop the romanticizing soft effect can often be enhanced even further The two strengths that are available serve for tailoring the effect to the subject B W Softspot Soft does not mean unsharp In spite of the fact that the effect of soft focus attachment is related to unsharp ness it should not be equated with it That is because good soft focus attach ments only coat a so called core image that remains very sharp with a subtle veil of unsharpness so that soft focus photos can be rich in details It is exactly this delicate combination of approximately 70 to 9075 sharp with only 10 to 30 of an unsharp blend that creates its pleasant charm In some types of soft effect filters there is a noticable reduction of contrast that results partly from refraction and partly from light scattering by the struc ture of the surface This ca
105. the image quality This provides the tightest possible tolerances with stringent quality control at every stage of pro duction B W is especially proud of its modern coating technology The MRC Multi Resistant Coating 09 technology that we ve developed exclusively is not only an enhanced process that assures virtually com plete elimination of surface reflections on both sides of each filter and thus leads to a maximization of light transmission In addition its extraordinary hard ness minimizes scratching and its water and dirt re pelling surfaces facilitate the care of filters Many effects that can be achieved during the original exposure cannot be achieved by subsequent digital imaging manipulation A special line of B W filters for the increasingly popular digital cameras In digital photography filters are also important tools for enhancing picture quality In spite of the effects that can be applied with imaging control programs that allow subsequent corrections not possible with traditional photography the basic rule is still valid Picture information that is not present in the original photograph cannot be reconstructed later with a computer unless they are painted in which is not authentic When UV or IR radiation have caused a haze and lack of sharpness it would be only remedi ally possible to counter this deterioration by bending the gradation curve increasing contrast and by arti ficial sharpness cor
106. the unwanted UV and IR ra diation that is repeatedly reflected between these layers affecting the wavelengths on both sides of the visible spectrum with a steep cut off It is used mainly on digital and video cameras with CCD sensors without an integrated IR protection filter because the IR sensitivity of the CCD sensor would other wise cause color changes and unsharpness That un sharpness results from the chromatic aberration of the lenses that are only corrected for visible light In the visible range the transmission curve is very high and straight This filter is completely clear and it re quires no increase in exposure Its filter factor is 1 B W Infrared Blocking Filter 489 xs 3 This IR blocking filter must not be confused with heat resisting protection filters for projectors or spotlights Instead it is intended for use as protec tion for IR sensitive CCD sensors or in the light path of illumination devices with low thermal characteris tics It suppresses infrared radiation gt 780 nm Be cause it gradually begins to absorb infrared radiation at 600 nm long wave red light is slightly weakened so that this filter has a subtle green tint But in CCD applications this can be readily corrected electroni cally Its filter factor is approximately 1 2 SPECIAL FILTERS B W UV Blocking Filter 415 2 B sc 400 26 27 1 Fr rr in AT Infrared black and w
107. tive in either case good tonal sep aration with the lighter gray of the toy and a darker gray for the dress The filters presented on the preceding pages nor mally serve to either contour the light source to the characteristics of the film that is being used block disturbing UV infrared radiation correct 3 4350 the color balance or the translation into gray tones and to eliminate deficiencies or strengthen charac teristics that appear too weak such as the blue sky Thus they are serving as functional tools while the special effects filters that follow act more like creative toys In other words the compulsory exercises are followed by the voluntary exercises As the designation filters for special effects indicates these lens attachments in a specific way somehow create an unusual effect Therefore they should always be used judiciously and sparingly re gardless of their type graduated filters soft focus attachments star and prism attachments GRADUATED T 40603 STAR FILTERS PRISM ATTACHMENTS gt SPECTRA FILTERS 36 37 Photo Thorsten Meywalt Ti Ma The very bright sky would without a filter but it gains structure by means of a B W Graduated Filter Gray 501 The clouds in the upper half still look heavy but they gain summery lightn
108. tone generated by pure green Brightness vs color contrast Unlike color photographs black and white photographs only have brightness con trast no color contrast That is why in the photography of objects for example things that have different colors but the same brightness will have similar gray values For instance when there is a blue toy in the foreground and red dress with the same brightness in the background they will be reproduced with the same gray values This is referred to as insuffi cient tonal separation Colored filters are helpful in such sit uations First the photographer must de cide which object is to be rendered lighter and which one is to be rendered darker Then he can select a filter color that 1 is similar to the color of the object that is to be shown lighter and that 2 is as com plementary as possible to the object that is to be rendered darker If the two colors are already nearly complementary like blue and orange he selects a filter color that is similar to that of the object that is to be rendered lighter If the two main colors are not complementary like blue and red a compromise can be used A blue filter lightens the blue color but it also darkens the red color a little But a green filter could also be used While it would only lighten the related blue color a little it would darken the red color more strongly than the blue filter would The photographer would have achieved his objec
109. uch weaker because our brain performs a corrective white balance Mired values make it much easier to calculate needed filter densities because the same differences in Mired values e g between the mired value of the light source and that of the film correspond to the needed filter value The number in the designation of the filter is the value of the filter measured in Dekamired 1 Deka mired 10 Mired In blue filters this val ue is negative i e in calculations it has to be used with a minus sign B W Conversion Filter KB 20 This is the correct filter when the illumination is provided by 40 to 150 Watt household incandescent bulbs and the transparencies are to show the subject in its original colors e g technical interior architec tural photographs or reproductions It should not however be used for moody interior pictures be cause unlike the KB 15 and 12 filters the KB 20 filter corrects the light to a neutral balance elimi nating the warmth that we might intuitively expect from bulbs Its filter factor is approximately 2 7 CONVERSION FILTERS LB FILTERS 18 19 ys a a Atmospheric haze causes a blue cast Partial color correction with KR 1 5 Warm autumn vegetation with KR 6 Without a filter a noticeable blue cast An 81 A filter neutralizes this blue cast occurs on the walls in the shade without adding a reddish tone to the clouds The large blue compone
110. uds in the sky gain more contrast a red roof and red flow ers are rendered darker in relation to plant greens as they would not with a purely yellow filter The yellow green filter accentuates the delicate spring time green in nature it makes portraits more dra matic Its filter factor is approximately 2 B W Green Filter 061 13 5 D This filter differs from the above yellow green filter primarily because of its increased red attenuation A red roof or red flowers will become even darker as will red lips and a dark tan and unfortunately so will skin blemishes This filter is ideal for nature photog raphy In object photography it is good for darker reds and lighter greens Its filter factor is appr 3 B W Light Blue Filter 080 261 B W Blue This filter renders blue tones lighter but yellow or ange and especially red darker Aerial perspective caused by haze and fog is increased the sky will be rendered lighter It is favored for tonal separation in object photography darker reds lighter blues and also for the correction of excessively light gray values of orange and red colors under artificial illumination Its filter factor is approximately 1 5 Filter 081 5623 This filter produces the same results as the 080 Light Blue Filter only more intensely Therefore it has the same application Its stronger effect make it a mood creating filter when photographing in fog or
111. un ter act the high blue cast in the shadow portions of color photographs caused by light coming from a blue sky It produces a warmer image tone and re duces the haze in distant scenes The exposure fac tor amounts to only 1 1 so for practical purposes it can be ignored Because of its very faint color a Sky light Filter can be kept on a lens constantly for pro tection as long as a slightly warmer color rendition is desired as it would be with color reversal films that tend to produce cooler colors The extremely hard water and dirt repelling MRC coating augments the protective effect of these B W filters FILTERS Filters as lens protection Good lenses are far more expensive than filters therefore it makes good sense to attach a filter to protect the lens sensi tive front element In order for this lens protection not to add a permanent filter effect the protective filter should consist of clear completely colorless glass with the highest possible transparency These are precisely the characteristics of the B W UV 010 Filter which furthermore also blocks the detrimental effects of ultraviolet radiation The extremely hard MRC coating with its water and dirt re pelling capability optimizes the protective effect and facilitates cleaning in case of accidental fingerprints or when the sur face becomes soiled This by the way is all the more important with digital cam eras whose picture quality because
112. used To lighten a subject P color use a filter of the same color darken subject color use a filter of a complementary color When two objects with different colors but with the same effective brightness are to be better dif ferentiated a black and white photograph use EY the filter of the same color as the color that is to be rendered lighter in the photograph La b uu PR ce m F EUR jrk L T u La de L ee ip i F 1 at wok 20 og vr a JA E ELO EF rM Eg xen SiS A TEX Er xum i F uu L 11 71 Pet i TE PT His pi mure t E t E Lee PR Nel utm A v rns ET E Ero rS eri T E sd E 1 ce art a a Trot Fe ee pee ee pan IQ ve ET E EL EE CU LER if AV es P pe I me E i i mo E HR

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