Sunday, 7 July 2013

Digital camera buying guide


Digital camera buying guide


For many people, buying a camera isn't an easy thing to do. It's not really a one-model-fits-all kind of product, so there's not just a single camera you can point to and say, "Buy this!"
In fact, it's the opposite; with such a range of types, sizes, features, and prices, unless you know your exact needs, you could very well end up disappointed with your purchase. And that's what this guide is all about: Helping you make the best camera purchase for your needs and budget.

The most important stuff

  1. There is no spec that tells you which camera is best. A higher resolution (i.e., more megapixels) or bigger zoom range doesn't make the camera better. I'll repeat: you're never looking for the camera with the most megapixels or longest zoom.
  2. Don't get hung up on making sure you've got the "best" in a particular class. The truth is, one camera rarely bests the rest on all four major criteria -- photo quality, performance, features, and design. (You may have noticed how few Editors' Choice Awards we give for cameras. That's partly why.) At least not at a friendly price. You want something best for you. And that may mean, for example, that it doesn't produce stellar photo quality, or at least photos that pixel peepers think are stellar quality.
  3. Try before you buy. Make sure it fits comfortably in your hand and that it's not so big or heavy that you'll leave it at home. It should provide quick access to the most commonly used functions, and menus should be simply structured, logical, and easy to learn. Touch-screen models can allow for greater functionality, but can also be frustrating if the controls and menus are poorly organized or the screen can't be calibrated to your touch.
  4. Point and shoot (budget)

    Less than $200.
    Who it's forKey characteristicsImage quality and performance
    Anyone who wants something that's a step up from a camera phone.Pocketable; lens fixed to body; zoom range usually less than 15x; small sensor; designed for mostly automatic operationGood enough for snapshots and social media, short vacation and kids video clips, and fast enough for food and the occasional good shot of kids and pets in action.

    Compact megazoom

    $200 - $350
    Who it's forKey characteristicsImage quality and performance
    Those who want a step up from a camera phone but frequently can't get close enough to get the photograph that's wanted.Pocketable; lens fixed to body; zoom range usually more than 20x; small sensor; designed for automatic and some manual operationBetter quality than a point-and-shoot; fast enough for kids and pets, short vacation, and kids video clips.

    Megazoom

    $350 - $500
    Who it's forKey characteristicsImage quality and performance
    People who want one camera that can shoot both close-ups and players' faces from the nosebleed seats.Big, with a small sensor; lens fixed to body; zoom range usually more than 26x; designed for automatic and some manual operation. The less-expensive models lack an EVF.

    These are sometimes misleadingly referred to asbridge cameras, as in bridging the gap between a compact and a dSLR. But despite their size and appearance, they have nothing in common with dSLRs; on the inside, they're pure point-and-shoot.
    Equivalent photo and video quality to a point-and-shoot, fast enough for the accidental action shot but mostly slow-moving subjects.

    Enthusiast compact

    $400 - $2,800
    Who it's forKey characteristicsImage quality and performance
    People who enjoy photography and like to play with settings but want something unobtrusive.Fits in a jacket pocket; lens fixed to body; small zoom range; medium-to-large sensor; some models have reverse Galilean optical viewfinders; designed for manual with some automatic operation.Photo quality good enough for those who want to get artsy and/or possibly sell their photos; short video clips; fast enough for shooting food but usually not action.

    Entry-level interchangeable-lens camera (ILC)

    $400 - $600
    Who it's forKey characteristicsImage quality and performance
    People who want something better and faster than a compact, but still want it as small as possible.Small enough to fit into a pocketbook; interchangeable lens; sensor sizes range from compact-camera-equivalent to those you find in dSLRs; designed for automatic and some manual operation. Usually no EVF or EVF optional.Comparable photo quality to an entry-level dSLR, better video quality than most compacts and point-and-shoots; fast enough for photographing kids and pets in motion.

    Entry-level dSLR $500 - $1,000 (with lens)

    Who it's forKey characteristicsImage quality and performance
    Anyone who wants better speed and quality than a compact and prefers shooting using an optical viewfinder.Big, with a relatively large APS-C sensor; interchangeable lenses; TTL optical viewfinder; designed for either manual or automatic operation.Comparable photo quality to an entry-level ILC; video quality varies significantly across brands; fast enough for photographing active kids and pets.

    Prosumer ILC $700+ (with lens)

    Who it's forKey characteristicsImage quality and performance
    People who enjoy photography and videography and like to play with settings and lenses but want something unobtrusive.Small enough to fit into a pocketbook; interchangeable lens; sensor sizes range from compact-camera-equivalent to those you find in dSLRs; designed for manual and some automatic operation; has EVF.Comparable photo quality to a prosumer dSLR; suitable for people who want to get artsy and/or possibly sell their photos; video quality varies significantly across brands, but can be good enough for indie videographers; fast enough for photographing active kids and pets.

    Prosumer dSLR $1,000+ (body only)

    Who it's forKey characteristicsImage quality and performance
    Advanced photographers who need speed and quality, as well as professionals with a tight a budget or who need secondary bodies.Big, with a relatively large APS-C or full-frame sensor; interchangeable lens; designed for manual operation; has TTL optical viewfinder.Comparable photo quality to a prosumer dSLR; suitable for those who want to get artsy and/or possibly sell their photos; video quality varies but can be good enough for indie videographers; fast enough for photographing sports-fast action.

    Pro dSLR $1,200+ (body only)

    Who it's forKey characteristicsImage quality and performance
    For people who need a reliable, durable, fully configurable and consistent camera that delivers best- quality images and perhaps fast action-shooting level performance.Big, with a large APS-C or full-frame (or bigger) sensor; interchangeable lenses; optical viewfinder; designed for fully manual operation.Photo and video quality that's good enough to sell to a knowledgeable buyer; performance fast enough to shoot sports or a bride fleeing the altar.

    How much zoom?

    A longer focal length lens lets you get closer without moving; for example, at 250mm you can see the observation deck of the Empire State Building, while at 1,000mm you can start to make out tiny people. In order to accommodate both wide-angle shots of an entire scene as well as long-distance close-ups, manufacturers have been making lenses with bigger and bigger zoom ranges. There are tradeoffs for this convenience, though. For one, it's hard to keep a subject in the frame when you're shooting at extreme telephoto. And a lens that has to be a jack-of-all focal lengths is generally a master of none of them. Generally, you probably don't need more than 20x.
    10x zoom, 25 to 250mm
    42x zoom, 24 to 1,000mm

    Key specs

    Resolution
    Generally referred to in megapixels. This number tells you how many pixels the camera uses to produce an image. Every modern camera has more than enough for any need. That's why it's not important as a spec. In fact, watch out for cheap cameras with high resolutions -- they usually lack the processing power to deal with the large images, which can slow them down.
    Lens
    There are two important specs related to all lenses: aperture and focal length(s). The lens' focal length, measured in millimeters, conveys the magnification of the image and the amount of scene covered by the lens (called the angle of view). As focal length increases, things look bigger and take up more of the frame. A lens that covers multiple focal lengths is a zoom lens, and the zoom spec is the ratio of the longest to the shortest focal length: a 20-100mm lens, therefore, has a 5x zoom. A lens of a single focal length is called a prime lens, and very flat ones are usually referred to as pancake primes. Note that the focal lengths as imprinted on the lenses of compact cameras will not be the same as the reported focal lengths; they don't reflect a multiplier that normalizes the length based on a frame of 35mm film, a reference point that adjusts for the multitude of sensor sizes in cameras. Sometimes called the crop factor, you really only need to think about it when looking at lenses for interchangeable-lens cameras.
    • Ultra wide angle (less than 18mm) is good for very large scenes where lens distortion adds rather than detracts from the appeal.
    • Wide-angle (around 18mm to 30mm) is good for group shots, landscapes, and street photography
    • Normal (about 30mm to 70mm) is good for portraits and snapshots
    • Telephoto (about 70mm to 300mm) is good for portraits and sports
    • Super telephoto (greater than 300mm) is good for sports, wildlife and stalking
    The aperture is the size of the opening that lets in light, alternatively referred to as an f-stop or f number. The lower the number the larger the aperture. The largest aperture usually varies over the zoom range; lens specs generally list the maximum aperture at the shortest and longest focal lengths. Thus, when the spec is listed as 18-55mm f3.5-5.6, that means the widest aperture is f3.5 at 18mm and f5.6 at 55mm. As aperture size increases, the area of sharpness in front of and behind the subject increases; area of sharpness is called depth of field. Since wider apertures let in more light and give you more control over depth of field, wider is better.
    A lens with a wide aperture is referred to as fast or bright and one with a narrow aperture isslow. Fast lenses are considered better than slow lenses; confusingly "fast" and "slow" have nothing to do with focusing performance. Also, watch out for lenses that start wide but get narrow very quickly. For instance, with a 24-120mm f2-5.9 lens you don't want the maximum aperture to jump from f2 at 24mm to f5.9 at 28mm.
    Sensor size and type
    Sensor size is the dimensions of the array of photoreceptors that create the pixels that become an image. Bigger sensors generally produce better photo quality, but the bigger the sensor the bigger the camera -- a larger sensor also requires a larger lens, more space for supporting electronics, and if the camera uses sensor-shift image stabilization, has an even larger footprint. Larger sensors are also more expensive to make, so the cameras are pricier.
    Sensor sizes are usually indicated in one of two ways: actual dimensions in millimeters or with labels such as "1/1.7-inch." The latter is an old convention from the early days of digital video, and don't represent actual sizes; 1/1.7 inch isn't equal to 0.59 inch, for example. However, they are accurate in a relative sense -- i.e., 1/1.7 inch is smaller than 2/3 inch. The sensors in point-and-shoot cameras are small at 1/2.3-inch, and those in camera phones even smaller, typically 1/3- or 1/3.2-inch.
    The most commonly used CFA, the Bayer pattern.
    There are a few primary sensor technologies. CMOS is the most popular. A variant, BSI CMOS (backside illuminated) is popular for compact cameras because it allows for greater low-light sensitivity on a relatively small sensor. However, the image quality in good light usually doesn't quite match that of traditional CMOS sensors. There are some manufacturer-specific variations of these as well, usually with different arrangements of the on-chip color filter array (CFA), which separates the incoming light into red, green and blue primaries that later get recombined to form the colors in the image. The most common CFA is the Bayer array; some CFAs have extra green-capturing sites, because green carries the most detail information (it's a human eye thing), such as Fujifilm's X-Trans, and Sigma's Foveon-based technology stacks the filters so that each pixel processes each color primary.
    Cheaper point-and-shoots still use CCD (charge-coupled device) sensor technology. Inexpensive CCDs don't deliver photo quality as nice as pricier CMOS sensors, but conversely, expensive CCDs like those used in medium-format cameras produce better photos. In general, CCDs are slow and poor for video.
    Light sensitivity
    A camera's sensitivity to light is specified as ISO sensitivity; the higher the number, the better the camera's ability to shoot in low light. However, as sensitivity rises so does the amount of noise -- those colored speckles you see in night shots. Cameras perform noise suppression to try to eliminate it, but that can result in smeary-looking artifacts. As a result, few cameras perform usably at the top of their rated ISO sensitivity ranges, making an unreliable spec. If you take it with a big grain of salt you can usually guess at the maximum usable sensitivity; for instance, a camera rated up to ISO 6400 will probably produce decent images up to ISO 800.
    Viewfinder
    While most consumer cameras these days have eliminated a viewfinder altogether, more-advanced models still have them. They're useful when it's hard to read an LCD in sunlight, and holding the camera up to your eye forces you into a more stable body position for shooting. There are basically three types of viewfinders: the type that used to be found on film point-and-shoots which gives you a direct view of the scene rather than a through-the-lens (TTL) view called a reverse Galilean; an electronic viewfinder or EVF; and the TTL optical viewfinder found on dSLRs. EVFs have an advantage when shooting video, as you can't simultaneously view and record video using a TTL viewfinder, plus they can simulate what the photo will look like. On the other hand, optical viewfinders are better for shooting action, though they have a tiny blackout period between shots, an EVF can only show you the action once it's already happened, not while it's in progress. Some EVFs are better than others for this, however. Important viewfinder specs are percentage coverage, or how much of the scene they can display -- 100 percent is best, obviously -- and effective magnification, which tells you how big the image looks in the viewfinder. A good viewfinder will also have a diopter adjustment, to fine tune the viewfinder focus for your vision or for glasses wearers.
    Image stabilization (IS)
    This is what keeps your photos from displaying camera shake. There are two physical types: in-camera sensor shift and in-lens optical. While they perform similarly, optical IS seems to work a little better while shooting video, but sensor-shift means that for interchangeable-lens models you don't have to wait for the manufacturer to put IS in the lens and the lenses will likely cost less and be a little smaller. Cheaper cameras may have electronic IS, which uses a combination of fast shutter speed and higher ISO sensitivities to help with motion blur. Unfortunately, this increases image noise and is less effective in low lighting.
    Battery life and type
    Most cameras use lithium ion rechargeable battery packs. While they offer greater battery life than readily available AA -- size batteries, they are generally designed for a specific make or model of camera. There are models using AA batteries, but they're usually lower-end compacts and larger megazoom cameras. When buying a camera, check out how many shots its battery has been rated for, a specification that has been standardized by CIPA.
    Burst/continuous shooting rate
    A measure of the number of frames per second a camera can capture, this spec can get quite confusing. Optimally, you want a high frame rate, at full resolution, with autofocus and autoexposure, for a reasonable number of frames. In order to report a high frame rate, the most common spec, companies play fast and loose with the other variables; so, for example, they'll say the camera does 10 frames per second (fps) -- but that's for 10 frames (i.e., 1 second), with exposure and autofocus fixed at the first frame, while the usable burst rate will be closer to 5fps.
    Video
    For typical vacation videos or videos of the kids, you want 1080/30p -- "1080" refers to 1,920x1,080-pixel resolution, also referred to as Full HD, whereas "30p" stands for 30fps progressive video. These days, you should stay away from 60i -- 60fps interlaced -- as it has more visible artifacts than even 24p. If a camera offers a frame rate greater than 60fps, that lets you create slow-motion videos. As for codecs, the algorithms that compress and decompress the video, look for a real codec like H.264 or AVCHD, which are subsets of MPEG-4, rather than Motion JPEG. The actual video files have formats like MOV (QuickTime), AVI (Microsoft Audio/Video Interleave), MP4, and MTS (AVCHD). Video recording also has a bit rate, the amount of data it encodes per second of video; for this, higher is generally better. Because AVCHD is really a playback specification, it's a lot less flexible with respect to available bit rates than H.264 MPEG-4. 

    Other features

    GPS
    If you love knowing exactly where you were when you took a photo, you'll want a camera with a built-in GPS (global positioning system) receiver. Typically found in rugged or higher-end cameras (add-on receivers are also available for some ILC and dSLR cameras), the GPS receiver uses satellite positioning to tag your pictures with location data. This location data can be read by software such as Google Earth or Picasa as well as photo-sharing sites to map where the photos were taken.
    Depending on the camera's capabilities, the GPS may also be used to tag photos with landmark information, set the camera's clock to local time, track your path on a map as you shoot, or even help with basic navigation on foot.
    The biggest downside is that it will drain your battery faster as it has to be left on so it can continue to update your location. It also won't work indoors or, in rugged cameras, underwater. It will add to the cost of the camera, too.
    One last note: Though some models state that they tag video with location information, the data is attached to the video as a separate file instead of being embedded as it is with photos. Generally this means the location information can only be viewed if the videos are played directly from the camera or with bundled software.
    Wi-Fi
    A few years ago, digital cameras with built-in Wi-Fi didn't make much sense. It was basically no better than using a USB cable, and a really slow one at that. Now, with more people using smartphones and mobile hot spots, a camera with Wi-Fi offers more than just slow wireless backup.
    The main function is still to wirelessly transfer photos and videos off the camera, but new models can back up straight to cloud services or networked computers as well as connect directly to a mobile device, so you can view, transfer, and edit shots, and then upload to sharing sites over your devices mobile broadband. Some models use Wi-Fi to remotely control the camera, too, using your mobile device's display as a viewfinder. It can also be used to piggyback on your smartphone's GPS receiver for tagging photos with location data.
    Samsung's WB850F is one of several Wi-Fi-enabled cameras available from the manufacturer.
    What this means is you can get things your smartphone's camera can't offer (e.g. better photo and video quality, a zoom lens, and more control) and still share on the go. Unfortunately, manufacturers currently use Wi-Fi as an upsell or add-on, so you many not be able to find the model you want with an option for Wi-Fi. In these cases, consider an Eye-Fi wireless SD card. These work like regular SD memory cards for storage, but also have a built-in Wi-Fi radio for wireless backups and transfers to Web sites, mobile devices, and computers.





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