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.
Mid-level D-SLRs ($1,000-$1,700) offer even better performance, more features and more rugged construction. They're good choices for photographers who can't afford (or don't want to lug around) a heavy-duty pro model. Some pros use a midlevel D-SLR as a backup to their pro models.
Naturally, top-of-the-line pro D-SLRs offer the best performance, the most features and the most rugged build. They're also relatively heavy, and most cost more than $3,000. No question, they're the most capable D-SLRs—the dream cameras of many—but they're not the best choices for everyone. They're designed specifically for working pros, and casual photographers will find them too complicated.
Each D-SLR manufacturer offers a wide range of interchangeable lenses for its bodies. Additionally, independent lens manufacturers offer a variety of optics for film and digital SLRs in two basic categories: lower-priced alternatives to lenses in the camera manufacturers' lines and lenses not available from the camera manufacturers. While the camera manufacturers' lenses can be used only on their cameras, the independent lensmakers' wares generally are available in mounts to fit most popular SLRs. The question is, how well do they integrate with your particular D-SLR and its digital features...