Tuesday, August 28, 2007

TTL vs. Non-TTL, Which is Better?

A few years ago, I was told that there were a lot of dental photography experts who were suggesting that dentists use "TTL" (Through The Lens) metering for their cameras. I was not a fan of TTL to begin with because I felt that it left too many decisions up to the camera, so I continued shooting and teaching non-TTL, histogram based dental photography.

The primary perceived value of TTL is that it's easy to use. In my opinion, based upon my experience and side by side comparisons, nothing could be farther from the truth. You see, SLR cameras weren't specifically designed for the very rigid demands of dental photography. We shoot images from about 1 foot away with the majority of the image being white and pink. Because our use is so far outside of the normal macro photography, the metering system just doesn't work right in the TTL mode. As a matter of fact, after learning how to properly use histogram based capture, most students have an "AHA!" moment related to a variety of close up images that they previously couldn't capture using TTL.

It doesn't seem to matter what camera system is being used, or whether one is using "E"TTL or "i"TTL. In either case, the images just don't compare to the beauty and sophistication of non-TTL photography.

When I changed from Nikon D-100 cameras to D-200 cameras, I figured that I would give the newest Nikon TTL system a chance. For over 2 months I actually tried everything in my power to give TTL a chance. Unfortunately, I could rarely capture an image that was even close to what I was getting with the non-TTL shots. To this day, I look back at the images I took during that period and cringe.

If you think that your camera and TTL are different, please feel free to look at the histogram. I virtually guarantee you that changing to a non-TTL image capture workflow will give you a far better result.

Have a fun time capturing some great images!!!

Sunday, August 5, 2007

The Facts about Dental Camera Purchases

Now, I know that this particular topic may not make me a lot of friends at some camera stores, but there's a lot of information that consumers should understand before buying a camera. I just want to share some of what I've learned, with the hope that you won't make the same mistakes that many new camera buyers make.

When buying a new camera for dental use, I would strongly recommend a Single Lens Reflex (SLR) camera. These are the type of cameras that have interchangeable lenses and generally do not show an image on the screen before you shoot an image. You need to look through the viewfinder. What distinguishes them from the standard "point & shoot" cameras is their incredible adaptability for the very specific task of taking high quality dental images. The ability to use specific lenses and flashes designed for up close (macro) photography makes SLRs a far better choice than "point & shoot" cameras, which need oddly designed accoutrements in order to adapt them for up close shooting, something they were never designed to do. There are several major dental photogrpahy companies tuting their latest and greatest "point & shoot" cameras as being as good as SLRs. Head to head comparisons just don't show this to be the case, so please do not be fooled.

(Above) An example of an SLR camera with a macro lens and flash setup. What you are looking at is a state of the art camera system for exquisite dental photography. Approximate cost for this system is around $2000 and is as good as any setup currently on the market. Sure, there's some instruction necessary, but that will be the case regardless of the camera type you choose, and the reward will be far greater with an SLR versus a "point & shoot".

(Above) An example of a "point & shoot" camera. Special additional adaptors are necessary to make this camera appropriate for dental use. The cost will vary from around $1000-1800 and just don't compare when shot head to head with SLRs.
The comparison of SLRs and "point and shoots" is a complex topic which could easily take up pages of discussion, however here I will merely tell you that while teaching my hands on courses in dental photography, I have never (yes, never) had a student who was using a "point and shoot" camera want to go back to it after properly learning how to use an SLR for dental photography. It's also good to keep in mind the fact that most point and shoot cameras that have been adapted for dental use are not cheap. For slightly more money, a great SLR combination can be found.

When looking for a camera, always look for an authorized dealer. I recently found a dental wholesaler who was trying to sell a specific camera to dentists. One call to the camera company rep confirmed that this reseller was not an authorized distributor for that camera. What this meant is that any dentist who purchased that camera from that distributor instantly had their warranty voided. That's a pretty daunting concept for an expensive piece of clinical equipment.

The standard lens in the industry is a 105mm macro lens. There are companies out there trying to sell odd magnification lenses (i.e.-60mm). Try to stick with the standard 105mm as it is generally accepted as the easiest lens to use and the most widely used as well. Make sure that it is a "Macro" lens, for up close photography. A non macro lens will not allow you to get close enough to your subject for an adequate image.

The "on-board" or built in flash will not be appropriate for the up close images, so you will need a good ring or point flash. Once again, this topic could take up a lot of space, and might be a topic for future discussion. For now, understand that whatever flash you purchase, it should also be rated for macro photography.

So, if you have a good SLR camera, a 105mm macro lens and an appropriate macro flash, all purchased from an authorized dealer, you will have the proper camera setup to potentially allow you to capture exquisite dental images. Of course, there's a lot more to learn but it's a great starting point.

As always, please feel free to contact me if you have any questions. We're all in this together...