All digital cameras take .JPEG images by default, which compresses your photos and compromises the details in each shot. Many DSLRs and compact interchangeable-lens cameras, and some advanced point-and-shoot cameras also allow you to shoot in RAW mode, which preserves all the data in your images without compression. Shooting in RAW lets you bring out more detail in your image during the editing process, but it also means that the file sizes on your images will be much higher. If you plan to shoot in RAW, make sure you have a high-capacity storage card to hold all that extra data.
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. It's also a good idea to test out a camera's autofocus before you buy; some cameras struggle to lock in on a focus point at full telephoto or in macro mode, meaning you may not be able to capture your perfect shot.
If you have an existing storage card that you'd like to use with your new camera, make sure that it's compatible with your new purchase. Most cameras on the market today use SD (Secure Digital) or SDHC (Secure Digital High Capacity) format cards. SDHC (Secure Digital High Capacity) cards are more expensive, offering storage capacities up to 32GB, but they're not backward-compatible with standard SD slots. There's also a new format on the block: SDXC, which supports storage capacities up to a whopping 2TB; those are even more expensive, and they aren't compatible with all SD/SDHC card slots.
In addition to storage capacity, there's also the speed issue to consider. SD and SDHC cards have a "Decoding Class" rating listed, which refers to the data-writing rate for each card. The higher the Class number, the faster the write speed; if you're planning on shooting video or using a high-speed burst mode, look for a Class 4 or Class 6 card at the very least.
To complicate matters further, there are a couple of other formats out there. Some cameras support MicroSD or MicroSDHC cards, a smaller version of the SD card format that isn't compatible with full-size SD slots. Older Sony cameras take MemoryStick cards, and older Olympus cameras use the XD card format; both companies' new cameras now support SD/SDHC cards. What's more, many higher-end DSLRs have a larger-format CompactFlash card slot.
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.
Some digital cameras quickly drain batteries--especially alkaline batteries--which can be expensive and annoying. Battery life and cost often aren't related; some inexpensive cameras have great battery life, and some expensive ones use up a charge quickly. Either way, it's a good idea to buy spare batteries.
Movies and Sound
The majority of today's cameras can capture video as well as still shots, and some even record 1080p high-definition video. If you plan on shooting a lot of video with your camera, here are some things to consider:
- Can the camera zoom in and out optically while filming video?
- Can you use autofocus while shooting video?
- Does your video-editing software support the format your camera records? Most cameras' video output will work with any video-editing program, but the AVCHD format is still incompatible with some software. That said, the AVCHD format will upload directly to YouTube.
- Do you have a Class 4 or Class 6 SDHC card? You'll want to pick one up to make sure it can handle the speed of video capture.
If you're torn between a digital SLR camera and an advanced point-and-shoot model, check to see whether the DSLR you're considering shoots video. A growing number of DSLRs capture high-definition video, and the larger sensors and lenses mean that the video quality is usually phenomenal.
All digital cameras let you shoot in fully automatic mode--just press the shutter release and you get a picture. Some 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.
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.
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 DSLRs offer multiple positions on their control dial for storing customized settings, and some point-and-shoots allow you to store customized settings as a mode within the scene modes menu or via the control dial.
One potentially helpful feature offered by almost every point-and-shoot camera is facial detection. 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.
Sign up for Computerworld eNewsletters.