3. Megapixels

All things being equal, DSLRs with lots of megapixels produce images of higher resolution that can be enlarged more. However, all things are never equal. For example, as I noted above, if too many pixels are packed too tightly on to a sensor, noise becomes a problem. Noise lowers both effective resolution and enlargement capability. In most situations you’re better off with a larger sensor with fewer pixels than a smaller one with more pixels. For example Nikon’s D2Hs has only 4.1 megapixels on a 23.3 x 15.5 mm sensor. The camera produces excellent images that can be enlarged to poster size. It is designed for very high speed multi-image capture, such as for sports like football, basketball and racing or for scientific imaging.

Well designed six megapixel DSLRs are fine for most amateur and prosumer photographers. Eight and 10 megapixel DSLRs can satisfy the needs of most professionals, though DSLRs with 12 to 16 megapixels make pros feel most at home.

LCD Size And Type

All LCD view displays on the back of DSLRs use Thin Film Transistor (TFT) technology. Some use TFT Polysilicon LCDs. The latter tend to be lighter, slimmer, brighter and more responsive than traditional TFT displays. Olympus DSLRs feature a TFT LCD display technology the company calls "HyperCrystal TFT". No technical details are offered, but claims are made that images on these LCDs are brighter and viewable from a wider angle in any direction than with standard TFT displays. I’ve seen the displays and must admit that the claims are not without foundation.

Historically, unlike point-and-shoot, non-DSLR digital cameras, you could not see a live image of your subject on a DSLR’s LCD. Once a photo has been taken, you can more or less immediately see a preview of that image and you can switch to image-view mode where you can look at images you’ve already taken. But, until recently, using the LCD to view and compose your image was not possible on DSLRs. That has changed with most of the current and all of the coming line of DSLRs from Olympus. These feature what is called "Live View" LCDs that allow you to use your DSLR’s LCD display just like a point-and-shoot’s display. Live LCD viewing seems a bit redundant on a DSLR where you’re already able to view and compose your image while looking through the lens. My limited experience with live viewing indicates that it’s better in situations where you don’t need to work quickly, perhaps in some studio environments.

There is one accessory that helps make all DSLR LCD displays easier to see in bright light, the LCD hood. The best of these are easily removed or collapsed when not needed. This eliminates problems associated with the large rear bulge these products create. For example the rear bulge makes it difficult to rest the camera on its neck strap against your chest.

Lenses Supported

If you already own a particular manufacturer’s lenses, you’ll probably want to make sure your DSLR of choice supports those lenses. Most modern DSLRs support modern lenses from the same or third party manufacturer. There are a few exceptions to watch out for. For example Nikon’s entry level D40 and D40x do not support auto focus with the company’s D and G lenses. This little limitation makes the D40 line unattractive to those who have these lenses and has generated more than a little heat on Nikon DSLR discussion groups. There are similar limitations with Pentax and Samsung DSLRs and their support for a wide variety of Pentax lenses.

Manual Focus

A DSLR should support manual focus, which is helpful in situations where you want to insure correct focus or where you want to deviate from "correct" focus to achieve an artistic effect, for example putting the foreground out of focus and something behind in focus or where you need to focus with a macro lens when taking extreme closeups. All of the DSLRs in this buyer’s guide support manual focus.