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Saturday, May 10, 2014

The Right Lens for Dental Clinical Photography

It kills me every time a dentist writes to me something like: "I've got this great camera and lens setup that I got handed down from my brother when he got a better camera, but I can't get good images. Can you help me use it better?"  More often than not, they have a zoom lens such as an 18-200mm or 55-300mm or something like that. NONE, I repeat NONE of those lenses are appropriate for dentistry. They are not macro lenses, which means that you can never use them up close to the subject. Almost all dental photography (with the exception of portraits) uses macro photography. If you don't use a macro lens, your images will be out of focus.
This Canon 17-85mm lens is amazing to use, but the "-" between the 17 and 85 signifies it's a zoom lens and NOT appropriate for dental use.

All lenses for dentistry are macro, except Nikkor lenses (Nikon's subsidiary that makes lenses for Nikon) which call them "Micro". 

The brand you choose is important for the camera you use. For instance, if you use a Canon body, use a Canon (or Tamron or Sigma) lens. If you use Nikon, you can use a Nikkor (or Tamron or Sigma) lens.  In this post, I'm not going to get into the idea of why I'm not a big fan of using "off brands" of lenses. Buy all from the same brand, so that when something goes wrong, there's no finger pointing by one company to another. Hand it in to the repair center and let them sort it out. It's worth the extra few dollars you'll pay on the equipment.  However, here I am going to briefly discuss the type of lens you should use.


Basically, with Nikkor and Canon, there are only a few choices. For Nikkor, you can go with the 85mm or the 105mm. For Canon, you can choose the 60mm or the 100mm (the less expensive of the two 100mm lenses Canon makes is fine). The 60 mm lens is simply too tough to use in dentistry. The lower the number the closer you need to be to the subject and with a 60mm lens, for a shot of just the front teeth, you'll literally be 3 inches from the patient. Not good. The flash will never be in a position to work well. So, for Canon, you've got only one choice, the 100mm lens.
This Canon EF 100mm f/2.8 Macro USM is a great choice for Canon users. DON'T buy the more expense $1050.00 100mm Canon lens. You don't need it.
For Nikon, the 105 is an amazing lens, but at almost $1000 I simply cannot recommend it over the way smaller and way lighter  85mm lens , which costs half the price. In case you're wondering, photo quality doesn't suffer at all. I've shot both and can't tell the difference in ANY use of the image.

This AF-S DX Micro Nikkor 85mm f/3.5G ED VR is an amazing lens at a great price for Nikon users.


Shot comparison of 85 vs 105mm Nikkor Macros. I can't see a difference and for an extra $500 I don't see the value.


Don't go crazy on this subject, but also don;t fall victim to buying the wrong equipment. As I said, I have DVDs to walk you through the entire process of buying, setting up and using your camera, flash and lens for maximum effectiveness, and minimal problems found HERE.

As always, I'm here for you should you have any questions or problems.

Best Wishes,
Glenn

7 comments:

  1. Hi Dr. Krieger,
    Thanks for the nice blog! I'm thinking of buying a camera for dental photography and I like your notes on camera bodies, flashes, and lenses.

    Regarding the 85 vs 105 Nikon Macro shoot-off, I think lighting is what that makes the subtle difference between the two setup. With 105 on your comparison photo set, I can see molars lit with (what I assume to be) Nikon R1 flash, but on 85 photo (with assumingly same flash) I can see less-lit buccal corridors. I think this is because the lens has to be closer to teeth and there is just too wide of an angle to let the light straight into buccal corridors. Also, the central teeth (or one on them) has more flash reflex on 85 compared to 105, again maybe because the lens has to be closer to teeth.

    I am nitpicking I know, but just my curious thoughts before I consider spending some money on a camera setup for dental photography. What do you think? Again, keep up the good posts Dr. Krieger!

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    1. Sina, thanks for the comment.

      I believe that this is simply attributable to a Type I error (seeing a difference where none exists).

      The idea of the 85mm lens came to be years ago from a very respected prosthodontist who is known for his dozens of published papers and textbooks that bear his name. I will not name him here because it isn't appropriate, but he told me that he had been using the 85mm lens for years with no decrease in image quality.

      I have shown the image above on screens around the world to rooms full of top notch dentists who saw no reason to switch to a 105 from an 85. I have been using the 85mm for years and enjoy what it does.

      I believe that you believe that you see differences. If you think it's worthwhile to spend more on the 105 and deal with a lens that is considerably larger and heavier, then go for it. I get no remuneration if you buy either lens,so I would support whatever choice you make.

      I'm just going on record that you would be the first dentist that I have ever encountered who feels that double the price, size and weight is a good idea in this case.

      Best Wishes,
      Glenn

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  2. Thanks for making such a pleasant blog, carry on posting more things, I feel pleasure to learn this all. Bryan P. Photography

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  3. Hello, thanks for the great blog! Quick question between Canon - EF 100mm f/2.8L Macro IS USM Lens and this one Canon - EF 100mm f/2.8 USM Macro Lens
    Is there any mayor difference? thanks!

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  4. Randall, that's a great (and common) question. In short, the IS is a higher quality lens, but IMHO opinion, not worth the additional $300. You'll do great wight he other one.

    All the best,
    Glenn

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  5. Informative. But this is about the statement that there is no difference between the 85 and 105mm Nikkor macros. With 85mm one you are closer to the subject and this introduces distortion which is there. This is obvious in the front view of the arch. The molars have a wrapped back appearance and are less visible in the 85mm picture. And the central incisors will be larger than in the picture taken with the 105mm lens. Since the camera and flash are closer the molars dont get illuminated. So if you have cash go for 105mm lens.

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    1. Ram, I appreciate your comment, but I respectfully disagree. While you are correct that an 85mm lens will force you to have to be closer, the concept of "warped molars" simply can't be seen, and I've tried to find it looking at the image again and again. The only valid argument against the 85 is greater shadows in the posterior if you aren't careful in retraction, but the anterior retracted shot is for anterior teeth and looking at the buccal surface profile of the molars, for which the 85 is more than adequate. We have lateral arch images to show the molars well. So, because of the massive weight and size differences between the 85 and 105, I would still strongly endorse the 85mm. It's not just a money issue.

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