Canon recently announced upgrades to a number of their top lenses, and for pro photographers these should generally be welcome. For dentists, however, there is one change that is not quite so good for one reason: the primary lens recommended for dentists and their teams, the Canon 100mm f/2.8 macro lens, has been updated to be an “L” glass (pros typically call their high-quality lenses “glass,” not “lens;” just a little FYI). What does this mean?
For practical purposes in dentistry, there is only 1 downside to this update, and that is that the new lens is more expensive than the previous lens by about $400, but without any real benefit. Sure, the image quality will be even higher, the lens will focus a bit faster, but the previous lens was completely adequate for everything we needed to do.
Click here to see the new lens.
Now, if you are a serious photographer outside the dental office, this lens does offer (to my mind) 1 truly significant improvement over the previous incarnation: it is waterproof or very water-resistant when combined with a Canon 7D, 5D Mark II, or any of the 1D series cameras. It is not water-resistant with any of the EOS Rebel series.
Due to this update, I am re-considering my usual recommendation to purchase the Canon 100mm f/2.8 macro for dental offices, and for cost reasons, many of you may want to look at the Sigma 105mm f/2.8 macro instead. If you can get your hands on one of the older versions (still available at some stores) or get a used one, then definitely go for it.
Good question, but I need a bit more information to help answer. What lens will you be using?
Here's the most likely problem: even if the extension tube gets you close enough to capture macro-like pictures, very few lenses will fit the ring flashes that work best for dental IO photography except for the macro lenses.
You could certainly try, but unless the ring flash fits the lens, you'll end up with the usual problem of very poor and uneven lighting in the mouth.
I hope that helps!