I want to start taking dental pictures. What equipment do I have to get? Is the camera the thing that matters the most? Or is it the eye behind the lens the thing that really matters. We can say that both things are important, but you can start taking high quality pictures without spending all your money.
An original article by Jon Gurrea and Jordi Manauta
What equipment do I buy? Oh, and I’m new into the photography world.
Many dentists pose this question to their colleagues. If your usual camera for any other purpose is the one in the cellular phone or if your last camera used film, you need to get back on track!
There are many camera companies but we are going to reduce the options to the ones with a bigger expand of accessories, lenses, flashes and other gadgets for dental photography, which is actually macro-photography.
First of all, we think that when we want to buy a camera body, which is in fact the less important thing we have to care of. Lenses and flashes are the most important devices you have to buy. In other words, don’t spend most of your money on the camera body and leave a little for your flash and lens. Your camera body will be obsolete in a few years while your macro lens and the flashes will last much longer in most cases.
We’ll take you through a little article that will help you choose the following:
1.Lens
2.Flash
3.Camera body
Form the professional and the economical point of view.
1. THE MACRO LENS
A macro lens is mandatory in dental photography. The lenses with the flower symbol are not valid at all. Get a proper macro lens. For Canon there are three major options, the 60mm and the 100mm macro lenses by Canon and the 105mm Sigma Lens.
The 100mm macro lens is the #1 option for a dentist. Yes it is heavier but the image is more true to life. The 60mm macro lens produces some compression due to a slight “fish eye” effect.
Fig.1
Lenses from Canon, in the left the new version of the 100mm macro lens with image stabilizer, in the right the old version of the 100mm macro lens. Luminosity and image stabilizer are not necessary in dentistry, only take them into account if you intend to do field macro photography or low depth field portraits.
Fig.2
Lenses from Nikon, in the left the old version of the 105mm macro lens, in the right the new version of the 105mm macro lens with image stabilizer. Luminosity and image stabilizer are not necessary in dentistry, only take them into account if you intend to do field macro photography or low depth field portraits. The new version of the Nikon Macro 105 VR as the Canon macro lenses is not extensible.
The 60mm macro lens allows you to make portraits not being too far from the patient, but when it comes to take intra-oral pictures you can be really close to the patient, almost touching him. Therefore we could reduce the use of 60mm macro lens to the orthodontists whose intra.oral pictures are never a 1:1.
Fig.3
A picture with a 100 mm macro lens, makes the image flat, but allows to do important close ups. This image is taken in a ratio of 1:1.8 (more or less 20 cm away from the patient) so the lateral (twin flashes) are able to illuminate the buccal corridor because being at long distance, the light will not be stopped by the cheeks.
Fig.4
A picture with a 60 mm macro lens, makes the image more rounded (fish eye), does not allow to do important close ups (i.e. 1:1, 1:1,2). This image is taken in a ratio of 1:1.8 (more or less 8 cm away from the patient) so the lateral (twin flashes) were almost touching the patient face and were not able to illuminate the buccal corridor because being at short distance.
Fig.5
Digital superposition of a picture taken at a 1:2 ratio with the 100 mm and the 60 mm, look at the differences in the posterior region due to the curvature “fish eye” effect of the lens.
Fig.6
The same Digital superposition of the picture taken at a 1:2 ratio with the 100mm and the 60mm, the red line follows the contour of the teeth from the image taken with the 100 mm (flat) and the yellow line following the image take with the 60mm (spherical).
2. THE FLASH
A ring flash (MT-14 EX for Canon) and the (EM-140 DG for both canon and nikon) is the most versatile and easiest flash you can buy. But the image quality is usually poor, with a strong white spot in the middle. But he pictures are generally well illuminated and for the posterior segments, especially when using mirrors, the Canon ring flash is a good choice. But don’t expect to make the most beautiful shots. Nikon SB-29 and similar are discontinued, those were exceptional ring flashes as well, if you have the chance to put your hands in one unit, just be sure that the TTL works with your camera.
The twin flash by Canon (MT-14 EX) and the twin flash by Nikon (R1 and R1C1) are the flashes you may use for your anterior shots. The classic twin flash by Canon, yes it has wires but works beautifully and you can take excellent pictures, the twin flash by nikon is wireless.
Finally you may feel cooler and think that need to move desperately to the cooler side. Then you’ll find the new 270 EX II wireless flash, you can buy two and use a bracket like the one offered by Photomed and take pictures as if you were using the classic twin flash.
Using twin flashes and a bracket allow you to set up your twin flashes as close as possible to the lenses and have a completely functional ring flash.
Fig.7
Anterior and posterior flashes for Canon, remember that if you choose to use the twin flashes with a bracket, the ring flash may not be completely necessary.
Fig.8
Anterior and posterior flashes for Nikon, remember that if you choose to use the twin flashes with a bracket, the Sigma ring flash may not be completely necessary.
Fig.9
Image taken with twin (lateral) flashes, texture is visible, especially the vertical one.
Fig.10
Image taken with ring flash. Look how the reflections are concentrated in the center of the teeth, giving a sense of flat image and poor vitality of the frame. Texture is visible but disordered.
Fig.11
The same situation captured with lateral flashes and bouncers, these kind of picture are more artistic, enhance better the morphology of the teeth and may not be the best for color communication.
3. THE CAMERA BODY
Finally we get to the point you have been waiting for. In order to get a decent DSLR camera body we have to realize that we don’t need to get a full-frame semi-professional camera. Just with a good body it will be enough.
The cheaper option for our purposes, yet having enough quality would be the Canon 700D or the Nikon D90, probably the most economic and versatile DSRL cameras. You can take pictures in both JPEG and RAW (which should be mandatory) and also shoot video.
The more expensive (not being a really expensive full frame camera), would be nowadays the 70D and the Nikon D7100 (the queens of the crop sensor), with excellent image resolution and more AF points to focus the image (not a really interesting feature in the dental field), the pictures are very high definition in both cameras.
Fig.12
Camera bodies options for Canon (left) and Nikon (right), with the economical option on the upper row and the high end solution on the lower row.
Please do not buy a full frame.
Now you have chosen your equipment, and you are ready to go. Next stop, setting up your camera and shooting!
This is what we can do with a D90 camera and the twin flashes with different set-ups, the possibilities are endless.
Fig.13
Twin flash photography with small soft boxes (9 cm x 9 cm) mounted on the bracket. This is direct diffused light.
Fig.14
Picture taken with the Twin flash with no diffuser, this is one of the pictures that gives more information about color, the twin flashes are located a few centimeters at the sides of the lenses.
Fig.15
The same twin flash picture with increased contrast and decreased brightness give a super powerful amount of color information.
Fig.16
Cross polarized filter mounted on the twin flashes or in the ring flashes. All glares, specular and diffuse will be completely removed for color analysis.
Fig.17
The same polarized picture with increased contrast and decreased brightness give even clearer color characteristics view.
Fig.18
Ring flash gives centered reflections and the contrary of artistic images. The advantage is that illumination is very regular and constant even though the picture is poor in three-dimensionality, color and texture.
Fig.19
Two large bouncers (can be mounted directly on the flash, or can be two pieces of paper) are probably the most impressive pictures for textures. Color information can be hidden if glares fall into the area of interest.
Fig.20
No flash photography, illuminated with a LED lamp, can only be taken with High ISO, only high quality cameras are able to do high ISO without adding noise to the scene.
Fig.21
No flash photography, illuminated with indirect sunlight (the light that enter from the office window), can only be taken with High ISO, only high quality cameras are able to do high ISO without adding noise to the scene, of course this light is not stable.
