CineSlide Lens Adjustment Manual General Pixel
Contents
1. Turn rotate the lens in its rear mount plate so this ellipse is oriented vertically long axis of ellipse is vertical This turning of the lens body in its mount is the roll adjustment it is how much the lens leans Isco III only The stock Isco lens mount does not provide a lock for the roll adjustment For lenses purchased with the CineSlide the mount was modified on request to include 2 lock screws to lock the lens roll adjustment do not lock them at this time Schneider only For Schneider lenses the TechHT Cinedigitar mount allows for this roll adjustment via the rear mount screws The lens plate has curved slotted holes that allow the lens to be rotated Orient the lens ellipse close to vertical and sung the mount screws for now For customer supplied Isco lenses the lens mount will not include lock screws These are not required but you will find later that the adjustment of the astigmatism ring on the front of the lens will tend to also rotate the lens and change it s roll adjustment For lenses without a roll lock you may choose to use Loc tite blue to stabilize your Isco If you use a threadlocker be very careful not to get any on the glass as it may damage the optical coating The lock screw modification is available from TechHT for CineSlide owners With the cross hatch pattern displayed and the anamorphic in the light path fine tune the roll position of the lens When the lens is rotated the projected image will skew2. accordingly Adjust so the image rectangle is square Just get close for now You will tweak on your second pass CineSuipE Anamorphic Lens Adjustment Manual v1 1 2007 TechHT LLC www techht com 3 amp 4 Pitch and Height up down aiming and distance of lens from floor ceiling NOTE A bright test pattern may be easier to use for the following adjustment instead of a grid NOTE For best performance the CineSlide mount height should have been made such that the anamorphic lens is close to the lens mount plate allowing only enough room to properly tilt and provide some slight height adjustment See lens offset values in mount kit installation docs While carefully holding the anamorphic so it cannot drop to the floor loosen its adjustment knobs or levers THE ISCO IS VERY HEAVY BULKY AND DIFFICULT TO HOLD Do not let it surprise you when you release it Move the lens up and down and tilt as necessary Watch the pattern on the screen The general object of this adjustment is to get the light beam to go directly through the center of the lens That is the rectangular 16x9 light beam is centered on the rear of the lens and to a lesser extent the 2 37 1 rectangle exiting the lens is centered on the front element of the lens On the screen watch the upper and lower pattern edges Do not worry about the sides yet Adjust the lens height and the tilt together so the a the light beam is centered on the rear of the lens b the image o
3. adjustments and relative position measurements 1 Horizontal position Left right centering relative to the light path 2 Roll How the lens is turned in its mount plate about its light path axis 3 Pitch The tilt of the lens in the up down directions 4 Height Vertical position of lens relative to floor ceiling 5 Yaw The angle the lens points to the left or right relative to the screen center point 6 Astigmatism The horizontal and vertical focus relationship Each of these adjustments is described below I recommend you do each adjustment in the order listed then return and start over with adjustments 1 6 fine tuning each Repeat as necessary 1 Horizontal Position left right This guide assumes the user has the CineSlide properly installed The lens mount and thus the lens should be centered left to right with the projectors LIGHT PATH when the CineSlide is in the Lens ON position This may be fine tuned by adjusting the CineSlide body mount position It has slotted holes to accommodate this fine tuning This one adjustment should generally be possible without revisiting as it is fairly straightforward and should not change significantly In my experience this adjustment is the most forgiving and is not necessary to have perfect unless you have a large light beam and a small lens 2 Roll turning of the lens in its back plate Look into the front of the anamorphic lens glass and you will see it looks like an ellipse
4. image width There should be no change in image height offset or focus when these lenses are placed into the light path Pixel Perfect Test Pattern Required To properly adjust these high end lenses you are going to need a high end test pattern A DVD pattern such as my GetGray calibration DVD www calibrate tv is NOT the best pattern to use Any video based DVD i e Avia DVE etc is NOT going to work well because these patterns are MPEG encoded and will not produce a single pixel line You simply can t get single pixel wide patterns with mpeg encoded DVDs it has to do with the encoding and compression methods What you need is a test pattern source that will display a single pixel pattern The ideal pattern is probably a single pixel grid For fine adjusting an alternating line horizontal and vertical grid pattern one pixel line off one on is nice As a minimum you should have a grid that has hard pixel edges i e exactly 1 to 3 pixels wide and accurately and perfectly fills the 16x9 image corner pixel to corner pixel If you don t have a high end test pattern it s going to be more difficult but not necessarily impossible to adjust There are several sources for such test patterns These include 1 Scalers Many users will be using an outboard scaler such as the Lumagen HDQ These scalers have internal test patterns that are ideal for this purpose 2 Projectors Some projectors have internal patterns including grids that are
5. CineSlide Lens Adjustment Manual Isco and Schneider Anamorphic lens with variable astigmatism adjustment Copyright 2007 TechHT LLC www cineslide com www techht com No part of this document may be used without written permission of the author This document may be freely distributed as written without modification General The CineSlide anamorphic lens transport by TechHT was designed for use with high end ground glass lenses from Isco and Schneider At the time of this writing the respective top of the line lenses were the Isco III and the CineDigitar Unfortunately neither of these high end lenses comes with a user manual of any kind Adjusting them can be a daunting task with no information or guidance To assist our customers we have compiled this basic guide for the adjustment of these lenses For purposes of this document I will refer to any wide aspect screen 2 35 1 2 37 1 2 40 1 as a scope Screen In my opinion 2 37 1 is the most correct for use with the aforementioned lenses because they are both 1 3333 expansion lenses 16 9 x 1 3333 2 37 It s not the source encoding that matters here it s the physical optical stretch of the full 1 78 1 panel size I think Stewart produces their scope screens at 2 37 1 by default unless requested otherwise but that s just going on what my local distributor said Regardless of your actual screen aspect these lenses are designed to give a 1 333 multiplication factor to the original
6. curved screen A longer throw may reduce it to an acceptable level Stewart makes very nice curved screens and is fluent with the proper curves required with specific lenses and throw combinations A curved screen will not have the radius one would think For example an 18 throw distance with an Isco III might call for a 50 radius curve The more typical cure for this issue is to simply zoom the projector slightly to move the edge of the image onto the screen border If you change the throw you need to readjust the lens particularly the astigmatism That s it Your Isco or Schneider should now be properly optimized providing you with the every highest quality anamorphic image possible today Hope this guide was helpful Best Scott Horton President TechHT LLC CineSuipE Anamorphic Lens Adjustment Manual v1 1 2007 TechHT LLC www techht com
7. d than say 47 17 32 Mark the top edge where these virtual sides would be Drop 2 weighted strings baby plumb bobs from these points to create your virtual 16x9 screen frame sides this assumes your screen was installed level and plumb of course Now armed with your virtual 16x9 screen frame and your high end test pattern project and verify your 16x9 image is aligned properly no anamorphic lens in place yet It should be to the edges flat on all 4 sides The pattern s sides should be the same distance from the outside screen scope width edges Get your zoom and focus set accurately At this point in addition to being properly aligned your focus should be correct your lens offset is properly adjusted etc Check you grid test pattern in the center and the edges If it s wrong here out of focus on one side etc the anamorphic lens won t make it any better Garbage in garbage out Lots of things can throw off the perfection of this non stretched pattern The things you may have control of are the spatial adjustments of the screen and projector and the mechanical projector lens adjustments The projector lens should be centered relative to the screen and pointed directly to the screen centerline unless your projector has a mechanical left right offset adjustment The screen must be plumb unless the projector was intentionally tilted etc The more perfect the screen projector relationship the better your image will be in 16x9
8. fering projection distances throws thus the need for adjustability Note that Prism based lenses do not have the ability to adjust astigmatism Instead they have a Sweet spot which is in the typical range of HT projection distances Their makers say they have a wider range of throws from this sweet spot for a given lens where although the aberration is not tunable it is not unacceptable The purists will want to adjust precisely and for that they will require an adjustable ground glass lens High end cylindrical ground glass lenses like the Isco III and CineDigitar lenses allow precision adjustment of astigmatism This allows correct focus across the full image for your specific installation and throw distance There are visible side effects when making this adjustment which affect the anamorphic image width Partly CineSuipE Anamorphic Lens Adjustment Manual v1 1 2007 TechHT LLC www techht com because of these side effects this adjustment is often misunderstood or misused It is NOT a focus adjustment per se It is NOT an image width or zoom adjustment Remember we started with a properly perfectly aligned and focused 16x9 image To adjust the anamorphic stretch induced astigmatism display the pixel perfect grid or alternating line pattern s With the lens in in Lens ON position adjust the astigmatism ring on the lens so the image width fits the scope screen left to right At this point presuming a 2 37 1 screen you should be ver
9. mode Get the 16x9 image perfectly setup now before expecting the expanded image to be right Adjusting the Anamorphic Lens The light beam Keep in mind that it is not usually the projector s lens we are literally adjusting to Many users attempt to install or blindly setup their anamorphic lens vertically centered with the projector lens only to have to move the anamorphic later What we DO align to is the properly adjusted 16x9 light beam The light beam is not usually coming out of the center of the lens Projector vertical offsets cause the light beam to exit the lens FAR off center of the lens vertical center point Some projectors even allow for a left right offset adjustment and for those the light path may not be coming out of the horizontal center either Although for best results with an anamorphic we recommend keeping horizontal offset at O or a minimum We mount and adjust our anamorphic to the properly aligned and focused image light beam not the projector lens per se The adjustment of an anamorphic lens in an iterative process You will make one pass of the adjustments then return to fine tune and readjust with another pass or more CineSuipE Anamorphic Lens Adjustment Manual v1 1 2007 TechHT LLC www techht com The adjustment and alignment of the lens is about 2 main things 1 getting its position set right relative to the light beam and 2 adjusting the astigmatism Adjustments The anamorphic lens has several
10. n the screen upper and lower edges are flat and aligned with the screen top bottom and c the image exiting the lens is in the general vicinity of centered This is a trial and error process Once satisfied with the upper lower alignment tighten the lens tilt height adjustments to lock them in place Be carefull not to let the lens roll while adjusting 5 Yaw left right aiming Do a rough adjustment on the lens yaw On the CineSlide loosen the 2 hex head adjustment screws on the lens mount plate using a 10mm wrench DO NOT loosen the center nut it is a safety fastener This will allow the lens to be pointed left right to adjust its yaw The CineSlide mount allows about 20 degrees which is likely way more than needed Center the projected image on the scope screen and as you change the yaw get the top and bottom edges parallel and the imge symetrical The actual image may be wider or narrower than the screen That is OK for now just get it close about the same amount over under on each side Tighten or snug the 2 10mm hex screws in the CineSlide lens mount plate before moving the lens 6 Astigmatism Astigmatism is an optical aberration inherent in anamorphic lenses of all types Astigmatism is where a different quality of focus occurs for horizontal and vertical directions for a projection distance e g pixels may be in perfect focus on the top and bottom but out of focus on their sides This aberration is different for dif
11. ns mount post safety screws are in place These screws are there to help prevent a loosened lens from sliding off the posts onto the floor Isco only Install and tighten the lens post safety slider stops so they ar eunder and against the Isco mount sliders For TechHT modified Isco III mounts GENTLY tighten the 2 roll lock setscrews These are custom setscrews with special plastic tips that will not mar the finish on the lens DO NOT OVERTIGHTEN The proper tightnes can be obtained as follows Optional 1 use Loc Tite blue on the setscrew to prevent it from working loose over time Remove one setscrew add a small amount of loc tite Screw it in and tighten by hand until it just touches the lens Using an allen wrench turn the setscrew ONLY 1 8 of a turn to tighten It does not take much Repeat for the second set screw Overtightening may damage the lens or mount If you have not already follow the mount safety checklist for your CineSlide mount CineSuipE Anamorphic Lens Adjustment Manual v1 1 2007 TechHT LLC www techht com Other issues Depending on your lens projector throw distance and screen type you may experience some pincushion in the image Pincushion is where the sides are bowed slightly This aberration is inherent with all anamorphic lenses It is usually attributed to small lenses and big projector panel sizes but mainly casued by shorter throws If you experience this issue the only real fix for it is a
12. there just for alignment reasons Those are also good candidates 3 Computer PC generated test patterns will work well if you use a HTPC or can connect a PC to the projector Displaymate www displaymate com is a source for good PC generated test patterns Setting up a HTPC is way beyond the score of this manual 4 Home made HD DVD s with static native resolution images that are not mpeg encoded These MIGHT work if the player plays the native image on a pixel perfect basis CineSuipE Anamorphic Lens Adjustment Manual v1 1 2007 TechHT LLC www techht com Before you begin Screen Alignment Installing a projector and screen is beyond the scope of this document However it is paramount to the adjustment process that one starts with a properly aligned projector and screen This becomes more problematic with a scope screen since the native projected image will be 16x9 So if you have a scope screen the first thing I recommend is to verify the 16x9 image is properly perfectly as possible aligned To do this measure the scope screen width and height Precisely find and mark it s centerline on the top edge with a light adhesive tape etc Using the screen s viewing height measurement determine the 16x9 image width by taking the height and multiplying it by 1 7777 Divide the result by 2 and this is the distance from the centerline to the virtual sides of your 16x9 screen Tip measure in mm it s more granular and easier to fin
13. y close to the design expansion of 1 33x lens At this proper expansion you should also be close on the astigmatism adjustment Ignore the image size and fine tune the astigmatism adjustment ring to balance the focus in the vertical and horizontal directions The vertical and horizontal should come into focus as this ring is adjusted There is only one setting for this adjustment that will allow both the horizontal and vertical components of the image to be properly focused simultaneously If the proper astigmatism adjustment produces an image that does not fit the screen you will have to zoom with the projector and start over To check your adjustment you can rock the projector s focus from out of back into focus then back out of focus As the pixels come into focus the horizontal and vertical lines will focus simultaneously if the astigmatism is set properly Now return to step one and fine tune each parameter as required Finish Once the lens has been adjusted double check all lens adjustment screws Final tighten the 2 10mm hex screws in the CineSlide lens mount plate yaw adjustment Triple check the lens adjustment knobs For TechHT Schneider mounts check all 4 levers These levers are adjustable in position or angle of the lever Pull the levers out away from the bolt and rotate them to the desired position and release Position the levers so they won t poke anyone and are out of the way Check that the le
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