Macro and Close ups

[JonathanW]

Greetings,

This is my first post and I consider myself to be a novice photographer. I am a dentist who just purchased a practice and I would like to set it up to include using digital photography in order to communicate with my patients. I have intraoral cameras but they do not take extraoral shots. I am looking for a camera to take head shots and close ups of teeth with consistent exposure and minimal shadowing.

Kodak takes a $400 camera, puts some manual settings on a dedicated program mode, adds a distancing guide ( a wire attached to the camera ) and it sells for $1600.

Another company takes the Cannon G5 ( which I happen to have ), adds a slip over simple looking macro lens, attaches a milky white piece of plastic to that lens which serves as a flash diffuser and sells the setup for $1600. Some marketing firm must feel that dentists want to spend $1600.

I would like to spend less ( $500 - $1000 ) and if I do have to spend more, I would like to feel better about the camera that I am purchasing.


Can anyone give me some suggestions?

Thanks, Jonathan

[dwig]

I've been a "macro freak" for most of my life (I'm border-line "old" and have the AARP card to prove it...). I'm currently using Nikon CoolPix cameras (950 & 990) for jewelry photography on a daily basis. I've used just about every method from simple close-up lenses to microscopes and everything in between.

There are several things that you need for dental photography that are somewhat specialized and, unfortunately, are somewhat out of line with the common characteristics of the built-in macro in today's digital cameras. The prices you are seeing are high largely because the stuff is cobbled up at very low volumes and, partially, because you have little other choice.

If you are crafty and skilled, you can press off-the-shelf pieces into a stepup that will work. I can't give you a perfect receipe but the following is a guide for starting out:

1. Most built-in macro configurations function at very close distances, sometimes using the wide-angle end of the zoom range. This is rather poor for dental work. You need a macro setup that works at a modest telephoto (35mm equiv of ~85-105mm) setting. Hence, looking for an off the shelf closeup lens that can be mounted on your camera is the likely answer. You would use the camera in its normal tele setting and rely on the closeup lens to perform the close focusing boost. As a starting place do the following:
a: take test shots without using your camera's macro; don't worry about them being out of focus. Record the distance between the front of the lens and the tooth for each shot.
b. determine which one yields the field of view you want and what distance that picture was taken at.
c. get a close-up lens whose diopter ("+" value) fits the following formula:
diopter = 1 / (distance measured in meters)
high presicision isn't necessary; if the distance is one ft its about 1/3 meter and you need a +3 closeup lens.

2. The close-up lens macro setup may yield only a relatively narrow range of distances that the autofocus system can handle. This, combined with the normal desire that pictures be very consistant patient to patient, is why the commercial setups use a wire frame or some other jig to force a consistant shooting distance. There are many ways to do this; I tend to dislike the complete wire frame jigs, prefering a simple bar that reaches to just below the center of the bottom edge of the image. This serves to measure the distance consistantly without being as objectionable to the patient. The cameras LCD will server to frame the picture. The bar can be a simple bent piece of aluminum bar stock with a 1/4" hole and a 1/4-20 screw to hold it to the camera's tripod socket.

3. The camera's built-in flash will not work well. You would either need to workout a diffuser or use other lighting.

Kodak's "Close-up Photography, Workshop Series" has, or at least the earlier editions had, some excellent information on a wide range of close-up photography. The current edition is listed at Amazon for about $10. While they discuss film cameras, little in them fails to translate to today's digital "film" and autofocus world.

[JonathanW]

Thank you for the detailed response. I am excited to get started.

Jonathan