Buyer's Guide 2008: Digital SLRs
Regardless of your budget or skill level, there’s a D-SLR that’s right for you
While there are advantages to truly compact digital cameras, the compacts are no match for digital SLRs in terms of image quality and performance. D-SLRs have larger image sensors, better autofocusing and metering systems and will accept a wide range of interchangeable lenses and accessories. There's a D-SLR for every photographer, from beginners to working pros, and they're all well outfitted with features and good performance. Even the lowest-priced entry-level models can be used successfully for "serious" photography.
Entry-level models are those designed for photographers moving up from a compact digital camera. These models are the least complicated and easiest to use and carry the lowest prices. But they offer lots of features and good performance, so more serious shooters on a budget can be quite happy with entry-level D-SLRs.
Pro models are designed for the demands of professional photographers. These models offer the most features, the best performance and the most durable construction. They also are the largest, heaviest, most complicated and priciest D-SLRs-definitely not for everybody.
Mid-range models offer lots of features and excellent performance at far less cost in terms of bulk and weight as well as money. They're not quite so rugged as the pro models, but budget-disadvantaged pros use them as backup or even primary cameras.
Sensor Format. D-SLRs come in several formats, determined by the size of their image sensors. Full-frame models (currently only the Canon EOS 5 and EOS-1Ds models and the new Nikon D3) have sensors the same size as a 35mm film frame, so any lens designed for 35mm film will provide the same magnification and angle of view that you've come to expect when used with these full-frame sensors.
Most D-SLRs use APS-C sensors, so-called because they're about the size of a Classic-format Advanced Photo System image frame. These smaller sensors crop in on the image formed by any lens and frame like a lens about 1.5x longer on a 35mm SLR: A 100mm lens used on an APS-C format D-SLR frames like a 150mm lens used on a 35mm SLR. This is great for telephoto fans, not so great for wide-angle fans. Fortunately, lens makers offer very short focal-length lenses designed specifically for the APS-C image sensor: Zoom lenses starting at 18mm can be obtained for all APS-C format D-SLRs at a low cost, and even shorter focal lengths are available.