Buyer's Guide 2008: Digital SLRs
Regardless of your budget or skill level, there’s a D-SLR that’s right for you
Olympus introduced a third format back in 2003, called Four Thirds (in part after its 4:3 aspect ratio), since taken up by Leica and Panasonic. Four Thirds System cameras employ even smaller sensors, with a 2x focal-length factor, and the entire system—camera bodies, lenses and accessories—was designed specifically for this sensor size, rather than adapted from 35mm gear. One advantage is that any Four Thirds System lens can be used with any Four Thirds System body, regardless of manufacturer.
Resolution. The glamour spec for digital cameras has always been pixel count, although the imaging engine, A/D converter and other features are equally if not more important to image quality. But pixel count does determine how big you can blow up your images. For most purposes, 6 to 8 megapixels is plenty; today, most entry-level D-SLRs provide 10 megapixels. Bear in mind that the higher the pixel count, the more space an image takes up on your memory card.
Stabilization. Canon introduced the first Image Stabilizer lens back in 1995, and Minolta introduced the first D-SLR with in-body sensor-shift stabilization in 2004. Today, there are quite a few stabilized lenses and camera bodies on the market. Stabilization is a very good thing if you shoot handheld and definitely is something to consider when choosing a camera (or lens).
Lens-shift stabilization has the advantage of providing a stabilized image in the viewfinder, as well as on the image sensor, and the stabilizer can be optimized for the specific focal length in question. In-camera sensor-shift stabilization has the advantage of working with all lenses that can be mounted on the camera; the drawback is that only the image on the sensor is stabilized—the finder image is not.
Dust Reduction. One big problem with interchangeable-lens D-SLRs is that dust can enter the camera and settle on the image sensor's protective filter every time you change lenses. Dust specks on the sensor then will appear in every shot you take. It's a large (and costly) inconvenience to take or send your camera to a repair shop to have the sensor cleaned on a regular basis, and it's easy to damage the filter if you try cleaning it yourself.
Olympus introduced the Supersonic Wave Filter in its first D-SLR back in 2003. This feature, vibrating 35,000 times a second, literally shakes dust off the image sensor assembly every time you switch the camera on, and it's very effective. Many of the latest models from all the major manufacturers now incorporate this feature, and it's definitely one to weigh heavily in your purchase decision.