Many consumers are much more familiar with compact digital cameras, since these models have flooded the marketplace. Digital SLR (single lens reflex) cameras are far less common, and up until 2005 were really only used by professionals. Digital cameras have always offered outstanding value, and now that the imaging technology has caught up digital cameras have the capacity to take crystal clear, brilliant photographs on par with those from film cameras. The SLR format is popular with professional and serious photography enthusiasts because it is the most versatile and convenient – the viewing lens is conveniently the same as the picture-taking lens, and lenses can be changed quickly and easily.
Digital SLR cameras offer significant advantages over film cameras. Images are immediately available for review – there's no need to wait to develop them to find out what you have shot. Digital removes film from the expense equation, which is a huge savings in both money and time. Digital also offers greater flexibility and convenience in changing white balance, ISO settings, and other technical settings from one shot to the next. With a digital SLR, you have complete control over every photo you take, and don't have to rely on the camera to make choices for you.
Digital SLR cameras also provide many benefits when compared against standard digital cameras. They have greater versatility among lenses, and invariably offer enhanced picture quality at comparable resolutions. Digital SLR cameras are made with photography enthusiasts in mind, and offer a range of professional-level features that non-SLRs do not have. They are built for speed. There's never a delay when you want to capture that photo of a lifetime when you're using a Digital SLR camera.
Resolution – Digital SLRs capture each image on a sensor, and record it onto a memory card. The more megapixels a camera has, the greater the information it can collect on the sensor. With more information stored, you can print your pictures at larger sizes, without losing image quality. For magazines and large print sizes (16x20 inches and greater), especially where you'll crop for detail, 8 megapixels is a proper starting point. Fine art landscape photographers and others seeking maximum detail should consider 10-megapixel-plus digital SLRs.
Frame Rate – 2-3 frames per second is appropriate for most consumers. If this is too slow, upgrade to the 6-8fps range. 8-10fps is necessary for some professional applications that require high-speed photography.
Autofocus Speed/Tracking – Most digital SLR cameras offer autofocus that is quick enough to handle everyday applications. If you notice a need for more speed, then consider a model that is optimized to compensate for fast-moving subjects. The top-end sports and news pro cameras definitely outperform the rest.
Image Stablilization – Optical stabilization has the advantage of letting you see the stabilized version while you're looking through the viewfinder, which can be crucial when framing at long focal lengths, but putting the technology in the lens generally results in more expensive lenses. On the other hand, mechanical (sensor-shift) stabilization will make the correction of camera shake happens inside the camera, not the lens. As a result, photographers can have various choices of lenses and always benefit from anti-blur technology.
Sturdiness – If you travel a lot, or are taking pictures in areas that are rugged in terms of terrain or weather, look for a model with metal construction, heavy-duty lenses, and water resistant and all-weather capabilities.
Additional Features – Which of these you need depends on what you are using your camera for, but improved digital SLR camera models feature an image histogram, comprehensive flash control, additional output and software capabilities, added battery life, and more.
Mirrorless Interchageable Lens Camera – If you'd like the higher image quality of a digital SLR but don't want a huge heavy camera, then consider a mirrorless interchangeable lens camera (MILC), or electronic viewfinder interchangeable lens (EVIL) - they're more the size of compacts but capture DSLR-like photos (and you can change lenses).
Nikon, Canon, and Olympus are names that everyone is familiar with, regardless of the type of camera. Each of these manufacturers has a long and storied history of delivering popular cameras at competitive prices, and their range of digital SLR cameras is no exception. Their cameras often lead the market in performance and advanced accessories, but they make digital SLRs for every level of price and performance. Pentax and Panasonic have specialized in offering affordable models – though they may lack some of the more advanced features of high-end models, they provide solid performance and outstanding value. Sony is a more recent entrant, and has won fans with its complete line of cameras, from bargain-priced entry models to high-end performers with all the bells and whistles, and everything in between.