How to Buy a Digital Camera

The Big Picture

Megapixels still matter a lot to digital camera shoppers, in part because manufacturers and retailers hype that specification above all others. If you're having a hard time figuring out which camera to buy, you may be tempted to make a decision based solely on megapixel count; that's why nearly all manufacturers print the number on the front of their cameras.

But a camera needs more than just a high pixel count to take great pictures, and a high megapixel count matters only if you want to make large prints. You should pay attention to other traits as well. For example, a lethargic camera that takes too much time between shots may miss the action, and a big, heavy camera may spend more time on the shelf than in your carry-on bag. A camera with no manual controls may take fabulous shots in bright sunlight, but lousy ones in more challenging situations.

Key Features

Megapixel count/resolution: If you intend to take pictures only to e-mail them to distant friends or to print at snapshot size, a camera of most any resolution will do. Even so, having more pixels gives you greater flexibility--you can print sharper pictures at larger sizes, or crop and print small sections of pictures. These days most cameras offer a resolution of at least 5 megapixels, which is enough to make a sharp 11-by-14 print.

Size, weight, and design: To some users, how much a camera weighs and whether it fits in a pocket may be more important factors than resolution. PC World has tested cameras that weigh as much as 2.3 pounds and as little as 4.2 ounces. Small cameras are convenient, but they frequently have tiny dials and few buttons, which make changing settings somewhat trying. Smaller cameras usually don't have many manual controls, either.

Zoom lens: Inexpensive cameras often lack a powerful optical zoom lens. If we had to choose between a camera with more optical zoom and one with higher resolution, we'd take the model with the more powerful zoom lens--it means you won't have to magnify your subject and then use software to crop the image (and discard some of the resolution as a result). Cameras now offer zoom ratings of up to 20X. These lenses are great for nature or sports photography, but unless the camera has good image stabilization, you may need a steady hand or a tripod to avoid blurry pictures at extreme telephoto lengths. You should try a camera's autofocus at full zoom: We've tested some models that were slow to focus at full zoom in low light.

Be wary of advertised zoom ratings--many vendors combine the optical zoom (which moves the lens to magnify the subject) with digital zoom, which merely captures fewer pixels and magnifies those. Optical zoom gives you all the benefit of the camera's maximum resolution, combined with the ability to focus in tight on faraway action.

Manual focus: For close-ups and situations in which a camera's autofocus doesn't quite cut it, switching to manual focusing can help you get the shot. Low-end cameras often omit manual focusing or allow only stepped focusing, which forces you to choose from a few preset distances.

Storage: At its highest resolution, a typical 5-megapixel camera can store six to eight images on a 16MB "starter" memory card. The size of the memory card that a camera ships with isn't terribly important, because you'll almost always have to buy another one (unless you're willing to transfer your images after every handful of shots). CompactFlash, SD (Secure Digital) Cards, and SmartMedia cards cost about $6 to $15 for 512MB, or $25 to $40 for 2GB. Beefier SD media is also available: The new SDHC (Secure Digital High Capacity) cards offer storage capacities of 4GB (for around $50) to 32GB (for around $350 to $700), but they're not backward-compatible with standard SD slots. Make sure that the camera you choose supports SDHC cards if you plan on buying one of them.

Batteries: Cameras use one or more of several types of batteries: AAs, either nonrechargeable alkaline ($5 for four) or rechargeable nickel metal hydride (NiMH, about $14 for four); high-capacity disposable CRV3s (around $10 apiece, and some cameras take two); or proprietary rechargeable batteries that can cost $25 to $65 to replace.

Movies and sound: Many cameras can capture video as well as still shots; this option is useful for taking short clips when you don't have a camcorder. Some models also will record an audio caption for still photos. If you're torn between a digital SLR camera and an advanced point-and-shoot model, keep in mind that digital SLRs don't shoot video.

Exposure settings: All digital cameras let you shoot in fully automatic mode--just press the shutter release and you get a picture. Most cameras also offer aperture- and shutter-priority modes, in which you adjust the size of the lens opening or how long the shutter stays open, and the camera automatically controls the other variable to give you the proper exposure.

Typically, you'd use aperture priority to maintain control over an image's depth of field--for example, to blur the background of a shot while keeping the foreground sharp--and shutter-priority mode to capture fast-moving subjects. A camera that relies exclusively on full auto would attempt to keep both the foreground and background in focus in the former example, and it would probably blur the moving subject in the latter.

Usually, cameras that offer priority modes also provide full-manual exposure control, in which you set both variables. These modes make a camera adaptable to almost any situation.

Menus: When evaluating a camera, consider how easily you can reach common settings--resolution, macro mode, flash, and exposure adjustments--and how easily you can play back just-taken images. Too many buttons, and you waste time trying to figure out which button does what; too many menus, and you waste time digging through them.

Scene modes: Some cameras try to entice prospective buyers, particularly beginning photographers, with a large number of scene modes--presets that are designed for a variety of settings and subjects, such as the beach, fireworks, and underwater. However, selecting one of these less common modes usually requires a trip to the menus, and multiple button presses. Some cameras let you assign one of the modes--or a custom mode of your creation--to a position on the control dial, where you can more easily access it. Some single-lens reflex (SLR) cameras offer multiple positions on their control dial for storing customized settings. Some point-and-shoots allow you to store customized settings as a mode within the scene modes menu.

One potentially helpful feature offered by many point-and-shoot cameras is facial recognition. In detecting people's faces, the camera aims to optimize both focus and exposure for the subjects, presumably to better effect than the more traditional portrait mode that almost every camera offers. Some new cameras even have smile recognition, which will automatically take a picture when someone in the frame smiles; this feature is great for baby pictures or for shooting an otherwise moody subject.

White balance: Almost all digital cameras allow you to choose a white-balance setting via presets. This setting tells the camera which elements in a shot should look white, and then by inference which elements should look black and what everything in between should look like. If you're finicky about color accuracy, look for a custom white-balance mode in which you press the shutter button while aiming at a white object.

LCD and viewfinder: All digital cameras have an LCD screen; these vary in size from 1.8 to 3.5 inches. The smaller size limits your ability to review just-taken images on the camera. A good LCD is essential for knowing whether you got the shot you wanted, and can usually give you an indication of whether it was properly exposed. Some new cameras have touch-screen LCDs that allow you to tap on subjects in the frame to focus on, as well as to navigate menus. If you're thinking about getting a camera with a touch-screen LCD, make sure you account for the screen-smudge factor.

LCD quality varies widely: Many wash out in sunlight or become grainy in low light, or the image may change if you tilt the camera slightly. If you can, try a camera outside before you buy it. Some cameras also have a viewfinder, which is a convenient backup for framing your shots (and if you turn off the LCD when not using it, you'll save battery power). Perhaps the best way to ensure an accurate exposure is to view the photograph's histogram on the LCD (if the camera offers this feature). A histogram is a graph that will show you highlights that are overexposed to the point of being pure white, and shadows that are underexposed and show as pure black.

Image stabilization/antishake: Some cameras offer antishake (also called image stabilization) as a shooting mode or as a feature that can be turned on and off. This is helpful when you're shooting photos in situations where it's difficult to get a sharp image, such as in low light. One disadvantage of an antishake shooting mode is that you can't use the feature in conjunction with another scene mode. Most point-and-shoot cameras use software to sharpen the resulting images. More advanced cameras, including SLRs, tend to employ one of two methods: optical image stabilization, in which an element in the lens adjusts to compensate for movement); or sensor movement, in which the camera's sensor moves in order to compensate for the shaking.

Wireless: Using Wi-Fi to transmit images to a PC, a printer, or a photo-sharing site may sound enticingly free of entanglements, but we'd recommend that you try this feature beforehand. In our reviewers' experience, sending Wi-Fi transmissions did not work seamlessly in some cases, and as a result was not worth the extra money this feature added to the camera's cost. You don't have to buy a Wi-Fi-enabled camera to send photos directly from your camera, however. The Eye-Fi card (2GB, $100) enables any camera with an SD Card slot to send photos wirelessly to your computer and to photo-sharing sites.