Getting The Most From D-SLR Camera Systems
You bought more than just a camera body
When you buy a compact digital camera, you buy a camera. But when you buy a digital SLR, you buy into a whole camera system. That SLR body accepts a wide range of lenses, flash units, viewfinder attachments, optional power sources and other accessories, all of which add tremendous versatility. So to get the most out of your purchase, you should look at the whole system, not just a particular camera model, when deciding which D-SLR to purchase.
The camera body is the heart of any SLR camera system, but especially so with a digital SLR. A film camera is basically a light-tight box that holds the film and lens. A digital camera is the film. The D-SLR's image sensor, A/D converter, image-processing engine and RAW/JPEG algorithms determine the very "look" of the images the camera produces.
When choosing a film-camera body, you're mainly concerned with its shooting-feature set, AF and metering performance, and what lenses and accessories can be attached. With a D-SLR, you must also consider the digital aspects: megapixels and image "look" (or "looks," with some cameras), and how the camera body, accessories and software work together to give you the best possible images and the most control.
There are three basic D-SLR categories. Entry-level models sell for between $500 and $700, yet offer a wide range of features and very good autofocusing and metering performance. They're also generally compact. The entry-level models are ideal for compact-camera users moving up to their first SLR, as well as for photographers on a tight budget.