Wednesday, November 23, 2011

Macro Lens = Portrait Lens ~

I had an interesting conversation with a client recently who was wondering why her full-face portrait shots were always a little disappointing.  It wasn't anything dramatic, and was hard to pin-point just what exactly was the problem; they just "never looked right".
But the problem turned out to be a common one: she believed her 100mm Macro lens was usable only for intraoral shots, and nothing else. Her Canon Rebel, as is often the case, came with an 18-55mm general-purpose zoom lens, and she was using this for her portrait shots. This is a good lens for a lot of things, but portraits is not among them. The reason? This zoom lens is very "short" (i.e., wide-angle) and while scenics are great, portraits are distorted, and it was this distortion that caused the images to look disappointing. Let's look closely at this:

This is how a full-face shot will look when you use that zoom lens (or any similar lens that comes with your camera). In this case, the zoom focal length was set on 18mm, its widest setting. Notice how greatly distorted it looks. In fact, to get the face to fully fill the frame, I had to shoot about 2 or 3 inches away from her nose. Obviously un-usable.

For this next one, I set that zoom lens to its 35mm focal length, so I wouldn't have to stand so close to her. It's an improvement, but not by very much. It still looks much too distorted.

When the lens is set at 55mm focal length, its longest, the image starts to look more appealing. Although there is much less  distortion, it's still there.

But here, with the 100mm Macro lens, the portrait looks excellent. There's none of the distortion caused by using the shorter zoom lens. In fact, outside the opertory, this very same Macro lens is an excellent one for many kinds of photographic projects. It's wonderfully sharp and fast. So take it outside and have fun with it. After all, of all the tools you use in your practice, your camera is the only one you can say that about!

Monday, November 7, 2011

Being an Informed Consumer ~

This topic is near and dear to my heart: how to be an informed consumer when shopping for your camera gear, whether in a retail store or website. It's one of the most common subjects of the emails and phone calls I receive. There are so many pro-quality digital camera systems out there, and most salespeople won't really have a clear idea of your dental imaging needs.
There are a couple of big misconceptions about digital cameras that the consumer (& even some salespeople!) can fall prey to: First, the more expensive the camera, the better pictures it takes, and Second (usually related to this), higher mega-pixels = better pictures. Neither of these is inherently true.
So what are the things you'd find on a camera like this $7000 Canon 1Ds Mk III? It's a wonderful camera with the kinds of features needed by the professional shooter: a huge 21 mp sensor for the commercial photographer, a fast 5 frames-per-second burst rate for the sports shooter, a full-frame sensor for the outdoor scenic shooter. Crucial for them, yes, but none of which applies to your imaging needs in the opertory.

What you do need is a light-weight, simple to operate camera that will produce blazingly sharp, color-accurate images every time you shoot. Fortunately, there's a lot of great ones to choose; from Canon, the Digital Rebels: T3, T2i & T3i, ranging from around $550 to $900 for the body. From Nikon: the D3100, D5100, & D90, in the same price range.  Even though moderately priced, they still have very sophisticated sensors ranging from around 12 to 18 mega-pixels. No slouches these!
So, you can put together a complete system -- camera, macro lens, & ringflash -- for a fraction of what just a high-end pro camera body would cost. Read back on some of my earlier posts here about those components. Remember, a quality lens has much more to do with making a superb image than the number of light-gathering pixels on the sensor!
There are excellent photo retailers and reputable on-line suppliers out there; email me if you'd like to know more about some of them. Need some hands-on guidance to learn how best to use them? Let me  know ~ we'll get together!