digital photography enhances diagnostics, communication, and
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1. While dozens of SLR cameras are available on the market only a handful are well suited to dental photography SLRs best suited for dental photography should have the follow ing features true macro lens available witha focal length of approximately 100 mm dual point and ring macro flashes available cus tomizable white balance RAW capability and an APS C crop sized sensor full frame sensor cameras will also suffice SLR cameras vary significantly in features and cost though not significantly in potential image quality More expensive units gen erally allow greater flexibility easier and deeper adjustment and are more robust Most modern cameras have resolution far beyond what is required for dental pho tography unless the user plans to print im ages beyond 1 in x 14 in It is generally accepted in the photographic industry that the necessary resolution for a quality print ed digital image requires approximately 300 dpi dots per inch Thus for an 1l in x 14 in image this translates to a minimum camera resolution of approximately 14 MP megapixels One of the best reasons for having a higher resolution camera is the Fig 1 Digital SLR cameras are adaptable accurate and well suited to the demands of dental photography Fig 2 Dual point flash systems provide excep tional fidelity particularly when attempting to capture internal and external characteristics of teeth in the esthetic zone Shown is Ni2. DENTAL PHOTOGRAPHY Topic Discussion Digital Photography Enhances Diagnostics Communication and Documentation Edward A McLaren DDS MDC Todd Schoenbaum DDS igital photographic equipment has evolved at a blistering pace Most of the recent developments signifi cant to dentistry involve the improvement in image management ease of use and fine tuning integrated high definition HD video and incremental improvements in techniques Good dental photography is pri marily the result of practice technique and dedication High quality equipment is help ful but is generally not the limiting factor The authors believe that digital single lens reflex SLR cameras Figure 1 versus consumer point and shoot type cameras of fer the most consistent control least image distortion and ultimately highest image quality and are therefore the best suited camera type for dental use Thus this article will focus primarily on SLR cameras and re lated components It should be noted how ever that point and shoot cameras do have a few niche applications within dentistry eg operating microscopes oral cancer 96 COMPENDIUM November December 2011 detection devices and they also generally require a shorter learning curve are some what less expensive than SLR systems and are adequate for taking basic images However for the reasons stated above the authors use and recommend digital SLRs CAMERA SELECTION
3. the D300S the D7000 and D90s Canon the 7D the 60D the T3i Though there are more expensive cameras available than these the crop sensor on these models provides an ideal balance be tween resolution noise and depth of field One of the main reasons for recommending these cameras is that they offer better white balance control than less expensive versions of SLR type cameras Another reason is that these Nikon or Canon models have flash sys tems that are ideally suited to dental macro photography MACRO LENS SELECTION The lens required for most dental photog raphy is a macro specific lens or micro for Nikon of approximately 100 mm focal length with a maximum f stop of approxi mately 2 8 Higher quality lenses generally include ease of use features such as image stabilization fixed lens length better image quality and faster autofocus when needed Currently there are seven lenses fitting the criteria needed for dental photography as listed in Table 1 www dentalaegis com cced FLASH SELECTION AND SETUP The camera component with the greatest effect on the quality of the final image is the flash setup There are several styles brands and approaches to macro flashes The au thors have found dual point flash systems Figure 2 to yield the greatest image qual ity ina portable package Dual point flashes generally consist of two flash heads mounted to each side of the lens with an adjustable flash bracket Alternat
4. a strong case to be made for uniform settings in dental photography The camera should be set to record as highest quality JPEGs for most images to allow for cropping zooming and printing For shade images or image requirements for admission to cosmetic or esthetic academies as well as other critical images the camera should be set to record images in RAW which will allow the great est flexibility in postprocessing and fine tuning of exposure For intraoral images the aperture should be set to f 32 though f 22 to f 45 will suf fice For full face images the aperture should be set to f 8 5 6 to f 11 will also suffice to allow for sufficient exposure and depth of field The exposure mode should be set to aperture priority often denoted as Av However the manual exposure mode M is preferable with certain models of camera and as a user develops expertise it gives the photographer the greatest con trol If using manual exposure mode it is recommended to set the shutter speed to approximately 1 250 setting the shutter speed as high as possible will also negate most of the ambient lighting The white balance is often a subject of debate It should be made clear that this topic is of no consequence for users re cording images exclusively as RAW as the white balance will need to be set in Camera Lenses Suitable for Dental Photography Nikon AF S VR Micro Nikkor 105mm f 2 8G IF ED Nikon AF S DX Micro Nikkor 85mm
5. f 3 5G ED VR FOR CANON Canon EF 100mm f2 8L USM IS Macro Canon EF 100mm f2 8 USM Macro AFTER MARKET LENS AVAILABLE FOR NIKON OR CANON Sigma 105mm f2 8 EX DG Macro Tokina 100mm AT X M100 Pro D f2 8 EX DG Macro Tamron SP 90mm F 2 8 Macro November December 2011 COMPENDIUM 97 DENTAL PHOTOGRAPHY postprocessing White balance settings on the camera control the color temperature of the JPEG image to ensure that the colors are accurately recorded The effect of the white balance is most noticeable in dental photography when it is set incorrectly and the gingiva appears too yellow or too blue In order to avoid such inaccuracies it is the authors opinion that a custom white balance setting be used This is done by taking a full frame image of a photographic gray card with the flash setup to be used and setting the camera s custom white bal ance to this image this process is different for each camera consult the user manual for specific instructions For beginners the white balance can alternatively be set to the flash white balance setting which will generally give suitable results In order to make use of this feature the lens must be set to the manual focus setting and the user must resist the temptation to focus by turning the focus sleeve instead of moving into or away from the subject For advanced users with higher end equipment it is advantageous to utilize a hybrid focus mode whereby
6. the ambient operatory light is distracting in video captures and is best resolved through the use of amonochrome setting Dentists and technicians alike will be significantly better equipped to make di agnostic decisions based on the video cap ture of the dynamic lip movements versus static image capture PORTRAIT IMAGES On camera flashes including the dual point and ring flash give a harsh unflattering il lumination for a portrait Softer lighting ie large and diffuse is desirable for postopera tive full faces and portraits For professional looking portraits and where space allows a minimum of one studio strobe light will need to be set up with a soft box and a re flector For portraits using this setup the strobe light should be positioned on one side of the subject and the reflector placed on the other to reflect light and give a more even illumination IMAGE MANAGEMENT Managing a vast number of images can be daunting The authors have found two software programs ideal for this purpose Adobe Photoshop Lightroom 3 and Apple Aperture These programs are very similar and allow users to customize image man agement to their liking Both programs also provide the ability to efficiently categorize sort find and clean up images Additionally many practice manage ment software programs allow inserting and categorizing patient images though typically their management and process ing tools are basic when
7. compared to these two programs WIRELESS IMAGE TRANSFER One of the most useful and exciting de velopments in digital photography is the ability to wirelessly transfer images from the camera to a computer or iPad made possible by the Eye Fi Pro X2 card Eye Fi Inc www eye fi The card is a secure digi tal SD memory card and wireless router in one The setup can be difficult and often requires IT assistance but the results are efficient and impressive Depending on the image size and type images can be shown full screen automatically on acomputer or iPad within seconds of capture The authors have found this to be highly useful during the patient examination process SUMMARY Digital dental photography is an exceptional tool for communication diagnosis and docu mentation So much of what is possible today with dental treatment hinges strongly upon dentists ability to fully capture the necessary diagnostic information and properly educate their patients With the proper training techniques equipment and implementa tion dental photography can significantly enhance the level of treatment provided Volume 32 Special Issue 4
8. ively ring flash sys tems Figure 3 consist of two flash heads in aring shaped diffuser body mounted to the end of the macro lens Ring flashes are ideal for situations where ease of use particularly for beginners is a priority over maximum esthetics ie surgical and intra operative images More discerning dental photogra phers will find that strategic implementation of soft boxes diffusers and polarizing films will give even greater control When using dual point flashes there are several techniques that will further improve consistency and image quality Through various experiments and trials the authors have determined that the ideal flash position for imaging the anterior dentition is with the flash heads positioned approximately 3 inches lateral to and 2 inches posterior to the front lens element Figure 4 In order to allow the requisite flexibility an adjust able flash bracket is needed to maximize a dual point flash system Advanced users may also find that attach ing polarizing film in parallel over the flash units will reduce glare and provide a deeper and clearer appreciation of the character ization of the anterior dentition Figure 5 Adding a polarizing filter over the front TABLE 1 FOR NIKON element of the lens will also allow the user to dial in or out the amount of specular re flection desired CAMERA SETTINGS Though SLR cameras may initially seem to offer a vast array of settings there is
9. kon s R1C1 system Fig 3 Ring flash systems are easy to use and well suited to surgical images and images using a mirror However the close proximity of the flash to the lens makes visualizing line angles translucency and surface texture dif ficult in the esthetic zone Fig 4 The 3 2 flash position provides con sistent results for shade matching images Achieving this position requires an adjust able flash bracket the bracket shown is from PhotoMed International www photomed net Fig 5 Nikon SB 200 flashes with a piece of polarizing film taped in from of the flash Volume 32 Special Issue 4 Y ABOUT THE AUTHORS Edward A McLaren DDS MDC Founder and Director UCLA Post Graduate Esthetics Director UCLA Center for Esthetic Dentistry Founder and Director UCLA Master Dental Ceramist Program UCLA School of Dentistry Los Angeles California Private Practice Prosthodontics and Esthetic Dentistry Los Angeles California Todd Schoenbaum DDS Assistant Clinical Professor Assistant Director UCLA Continuing Education Assistant Director UCLA Center for Esthetic Dentistry UCLA School of Dentistry Los Angeles California ability to enlarge an image and crop it At higher resolutions there will then still be adequate detail in the image The authors current recommendations for SLR cameras based on the unique needs of dental photography are as follows cam era bodies Nikon
10. the autofocus trigger is programmed to an alternative button The lens is set to the desired mag nification the subject is positioned in the frame as desired the autofocus button is depressed and immediately following con firmation of focus lock the shutter is fired The hybrid focus allows great consistency with increased accuracy VIDEO SLR cameras include video capture Much of the initial diagnostic decision making in complex esthetic cases involves recording the position of the teeth in relation to the face and lips Generally such images include the following views lips in repose M view maximum reveal E view and fricative or 98 COMPENDIUM November December 2011 Fig 6 A flash diffuser is a compact way to turn a standard hot shoe flash into good portrait lighting A P position F view The position of the teeth in relation to the lips is a dynamic re lationship and is best recorded as such A video record of the teeth and lips through out these movements can provide a signifi cant improvement in diagnostic accuracy Though the flash cannot be used for video video light sources are available the au thors have found the ambient operatory lighting to be sufficient with the following settings ISO 800 f 8 shutter speed 1 30 to 1 60 monochrome magnification 1 3 Image stabilization vibration reduction is invaluable for video recording use of a tripod is a viable alternative The color temperature of
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