How to Buy a Digital CameraThere are so many options in the world of digital cameras, its easy to getconfused. Heres how to pick the camera that fits you perfectly.By Tim Moynihan and PCWorld Staff, PCWorld Feb 23, 2011 2:00 amThe Specs Explained Different specs are important to different people, but there are a fewgeneralizations we can make when it comes to cameras.Megapixel CountIf you intend to take pictures only to e-mail them to distant friends or to print at snapshot size, acamera 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. Thesedays most cameras offer a resolution of at least 10 megapixels, which is overkill for mostshooters. 5 megapixels is enough to make a sharp 8-by-10 print. 8 megapixels is enough tomake a sharp 11-by-14 print. A 10-megapixel camera can produce acceptable prints of up to 13by 19 inches, though they may lose some detail. Images from a 13-megapixel camera look goodat 13 by 19 inches and can be pushed to 16 by 24 inches. Many digital single-lens reflex (SLR)cameras today exceed 13 megapixels-all the better to creatively crop your images.Image QualityAll megapixels arent created equally; cameras with larger sensors and lenses normally takebetter shots, regardless of the megapixel count. Bigger sensors normally create better images,as do higher-quality lenses; this is why DSLRs take such stunning photos. If you cant get anyhands-on time with a camera before deciding whether to buy it, check the specs to see how bigits sensor is, and look at the physical size of the glass on the front of the camera. If both are big,it most likely offers good image quality.Shutter Lag and Startup TimeEven if the camera youve decided to buy has some drool-inducing specs, shutter lag may keepyou from capturing the perfect shot. When it comes to shutter lag, a camera can let you down ina handful of ways: a slow shot-to-shot time, a slow startup-to-first-shot time, and a laggyautofocus that has trouble locking in on a crisp shot.You can check for only one of these problems by scanning a cameras spec sheet: To get agrasp on a cameras shot-to-shot time, look for the cameras "burst mode" or "continuousshooting" count in shots per second. This is the number of shots a camera will take in rapid-firesuccession as you hold the shutter button down. If youre interested in shooting a lot of sports oraction photography, look for a camera with a continuous shooting mode of at least 3 shots persecond; keep in mind that the continuous shooting speeds usually refer to situations with theflash turned off, as the time needed to recharge the flash will usually be longer than the shot-to-shot time. Some cameras are built for high-speed shooting with shot rates much higher than that,
but usually they significantly reduce the resolution of each photo in order to speed up imageprocessing and write speeds.The other forms of shutter lag are important reasons to get some hands-on time with any camerabefore you buy it, if possible. Check to see how long the camera takes to power on and snap afirst shot; generally, anything close to a second is considered fast. Another good hands-on, in-store test is to see how long the cameras autofocus system takes to lock in on a shot after youpress the shutter button halfway. If the camera searches in and out for more than a second,youd be better off with another camera for sports or spur-of-the-moment casual shots.Size, Weight, and DesignTo some users, how much a camera weighs and whether it fits in a pocket may be moreimportant factors than resolution. Slim cameras are convenient, but they frequently have tinydials and few buttons, which make changing settings somewhat trying. Smaller cameras usuallydont have many manual controls, relying on automated in-camera settings that pick the right in-camera settings for your shot. These auto modes normally do a great job, but you have lesscontrol over the look and feel of a photo.Zoom Lens and Image StabilizationInexpensive cameras often lack a powerful optical zoom lens, but thats changing. Among thenew breed of $200-range cameras are a few pocket megazooms: compact cameras with opticalzoom lenses as powerful as 10x optical zoom.If we had to choose between a point-and-shoot camera with more optical zoom and one withhigher resolution, wed take the model with the more powerful zoom lens--it means you wonthave to magnify your subject and then use software to crop the image (and discard some of theresolution as a result).If youre buying a DSLR or a compact interchangeable-lens camera, both the zoom range andthe stabilization features depend on the lens youre buying. A few DSLRs and interchangeable-lens compacts have in-body image stabilization, meaning that your images will be stabilized byin-camera mechanics regardless of which lens you attach. If your camera doesnt have in-camera stabilization features, optically stabilized lenses are available, but theyre often a bit moreexpensive.Fixed-lens cameras now offer zoom ratings of up to 36X. These lenses are great for nature orsports photography, but unless the camera has good image stabilization (look for a camera withoptical image stabilization) or a very fast shutter, you may need a steady hand or a tripod toavoid blurry pictures at extreme telephoto lengths. You should try a cameras autofocus at fullzoom: Weve tested some models that were slow to focus at full zoom in low light.Also note that not all high-zoom cameras are created equal. You know how you have to askeveryone in your group shot to gather in close to get in the shot? A wide-angle lens can solvethat problem, so pay attention to the wide-angle end (lowest number) of the optical zoom range,not just the telephoto end (highest number). If you take a lot of group shots or landscape shots,the wide-angle end of the lens is even more important; it lets you capture more of the scenewhen youre zoomed all the way out. A good wide-angle lens starts at about 28mm or less on thewide-angle end; the lower the number, the wider-angle the lens.
Be wary of advertised zoom ratings--many vendors combine the optical zoom (which moves thelens to magnify the subject) with digital zoom, which merely captures fewer pixels and magnifiesthose. Optical zoom gives you all the benefit of the cameras maximum resolution, combined withthe ability to focus in tight on faraway action.RAW ModeAll digital cameras take .JPEG images by default, which compresses your photos andcompromises 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, whichpreserves all the data in your images without compression. Shooting in RAW lets you bring outmore detail in your image during the editing process, but it also means that the file sizes on yourimages will be much higher. If you plan to shoot in RAW, make sure you have a high-capacitystorage card to hold all that extra data.Manual FocusFor close-ups and situations in which a cameras autofocus doesnt quite cut it, switching tomanual focusing can help you get the shot. Low-end cameras often omit manual focusing orallow only stepped focusing, which forces you to choose from a few preset distances. Its also agood idea to test out a cameras autofocus before you buy; some cameras struggle to lock in ona focus point at full telephoto or in macro mode, meaning you may not be able to capture yourperfect shot.StorageIf you have an existing storage card that youd like to use with your new camera, make sure thatits compatible with your new purchase. Most cameras on the market today use SD (SecureDigital) or SDHC (Secure Digital High Capacity) format cards. SDHC (Secure Digital HighCapacity) cards are more expensive, offering storage capacities up to 32GB, but theyre notbackward-compatible with standard SD slots. Theres also a new format on the block: SDXC,which supports storage capacities up to a whopping 2TB; those are even more expensive, andthey arent compatible with all SD/SDHC card slots.In addition to storage capacity, theres also the speed issue to consider. SD and SDHC cardshave a "Decoding Class" rating listed, which refers to the data-writing rate for each card. Thehigher the Class number, the faster the write speed; if youre planning on shooting video or usinga 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 camerassupport MicroSD or MicroSDHC cards, a smaller version of the SD card format that isntcompatible with full-size SD slots. Older Sony cameras take MemoryStick cards, and olderOlympus cameras use the XD card format; both companies new cameras now supportSD/SDHC cards. Whats more, many higher-end DSLRs have a larger-format CompactFlashcard slot.Battery LifeCameras use one or more of several types of batteries: AAs, either nonrechargeable alkaline ($5for four) or rechargeable nickel metal hydride (NiMH, about $14 for four); high-capacitydisposable CRV3s (around $10 apiece, and some cameras take two); or proprietaryrechargeable batteries that can cost $25 to $65 to replace.
Some digital cameras quickly drain batteries--especially alkaline batteries--which can beexpensive and annoying. Battery life and cost often arent related; some inexpensive camerashave great battery life, and some expensive ones use up a charge quickly. Either way, its a goodidea to buy spare batteries.Movies and SoundThe majority of todays cameras can capture video as well as still shots, and some even record1080p high-definition video. If you plan on shooting a lot of video with your camera, here aresome 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 camerasvideo output will work with any video-editing program, but the AVCHD format is still incompatiblewith some software. That said, the AVCHD format will upload directly to YouTube.- Do you have a Class 4 or Class 6 SDHC card? Youll want to pick one up to make sure it canhandle the speed of video capture.If youre torn between a digital SLR camera and an advanced point-and-shoot model, check tosee whether the DSLR youre considering shoots video. A growing number of DSLRs capturehigh-definition video, and the larger sensors and lenses mean that the video quality is usuallyphenomenal.Exposure SettingsAll digital cameras let you shoot in fully automatic mode--just press the shutter release and youget a picture. Some cameras also offer aperture- and shutter-priority modes, in which you adjustthe size of the lens opening or how long the shutter stays open, and the camera automaticallycontrols the other variable to give you the proper exposure.Typically, youd use aperture priority to maintain control over an images depth of field--forexample, 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 wouldattempt to keep both the foreground and background in focus in the former example, and it wouldprobably blur the moving subject in the latter.Usually, cameras that offer priority modes also provide full-manual exposure control, in whichyou set both variables. These modes make a camera adaptable to almost any situation.MenusWhen 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-takenimages. Too many buttons, and you waste time trying to figure out which button does what; toomany menus, and you waste time digging through them.Scene ModesSome cameras try to entice prospective buyers, particularly beginning photographers, with alarge 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 youassign 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 dialfor storing customized settings, and some point-and-shoots allow you to store customizedsettings 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 facialdetection. In detecting peoples faces, the camera aims to optimize both focus and exposure forthe subjects, presumably to better effect than the more traditional portrait mode that almost everycamera offers. Some new cameras even have smile recognition, which will automatically take apicture when someone in the frame smiles; this feature is great for baby pictures or for shootingan otherwise moody subject.Unique Shooting ModesWith the megapixel wars officially over, camera manufacturers are focusing on other ways tomake their offerings stand out from the pack. Some in-camera features are worth the price ofadmission alone, and they vary by vendor. For example, Casio has a high-speed shooting modein many of its cameras that takes up to 60 shots per second. Nikon has a camera with a projectorin it. Sony has a Sweep Panorama mode that lets you press the shutter button once and thenpan across a scene to create an instant panoramic image. Canon and Olympus both have scenemodes that make large objects look like miniature models, and several companies have camerasthat shoot 3D images. Youll also find quite a few cameras available now with built-in GPS andmapping features. When it comes to cameras, dont be afraid to dive into the details; you mightdiscover a cool feature hiding in the spec sheet that makes a camera a top contender formeeting your needs.White BalanceAlmost all digital cameras allow you to choose a white-balance setting via presets. This settingtells the camera which elements in a shot should look white, and then by inference whichelements should look black and what everything in between should look like. If youre finickyabout color accuracy, look for a custom white-balance mode in which you press the shutterbutton while aiming at a white object.LCD and ViewfinderAll digital cameras have an LCD screen; these vary in size from 1.8 to 3.5 inches. The smallersize limits your ability to review just-taken images on the camera. A good LCD is essential forknowing whether you got the shot you wanted, and can usually give you an indication of whetherit was properly exposed. Some new cameras have touch-screen LCDs that allow you to tap onsubjects in the frame to focus on, as well as to navigate menus. If youre thinking about getting acamera with a touch-screen LCD, make sure the screen is responsive--and account for thescreen-smudge factor.LCD quality varies widely: Many wash out in sunlight or become grainy in low light, or the imagemay change if you tilt the camera slightly. If you can, try a camera outside before you buy it.Some cameras also have an eye-level viewfinder, which is a convenient backup for framing yourshots (and if you turn off the LCD when not using it, youll save battery power). Perhaps the bestway to ensure an accurate exposure is to view the photographs histogram on the LCD (if thecamera 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 aspure black.WirelessUsing Wi-Fi to transmit images to a PC, a printer, or a photo-sharing site may sound enticinglyfree of entanglements, but we recommend that you try this feature beforehand. In our reviewersexperience, sending Wi-Fi transmissions did not work seamlessly in some cases, and as a resultthis feature was not worth the extra money it added to the cameras cost. You dont have to buy aWi-Fi-enabled camera to send photos directly from your camera, however. Eye-Fi cards enableany compatible camera to send photos wirelessly to your computer, to photo-sharing sites, andeven directly to a mobile phone. And TransferJet wireless technology lets you transmit photosand video between compatible devices simply by holding them close to one another.