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How to buy a digital camera
1. How to Buy a Digital Camera
There are so many options in the world of digital cameras, it's easy to get
confused. Here's how to pick the camera that fits you perfectly.
By Tim Moynihan and PCWorld Staff, PCWorld Feb 23, 2011 2:00 am
The Specs Explained
Different specs are important to different people, but there are a few
generalizations we can make when it comes to cameras.
Megapixel Count
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 10 megapixels, which is overkill for most
shooters. 5 megapixels is enough to make a sharp 8-by-10 print. 8 megapixels is enough to
make a sharp 11-by-14 print. A 10-megapixel camera can produce acceptable prints of up to 13
by 19 inches, though they may lose some detail. Images from a 13-megapixel camera look good
at 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 Quality
All megapixels aren't created equally; cameras with larger sensors and lenses normally take
better 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 can't get any
hands-on time with a camera before deciding whether to buy it, check the specs to see how big
its 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 Time
Even if the camera you've decided to buy has some drool-inducing specs, shutter lag may keep
you from capturing the perfect shot. When it comes to shutter lag, a camera can let you down in
a handful of ways: a slow shot-to-shot time, a slow startup-to-first-shot time, and a laggy
autofocus that has trouble locking in on a crisp shot.
You can check for only one of these problems by scanning a camera's spec sheet: To get a
grasp on a camera's shot-to-shot time, look for the camera's "burst mode" or "continuous
shooting" count in shots per second. This is the number of shots a camera will take in rapid-fire
succession as you hold the shutter button down. If you're interested in shooting a lot of sports or
action photography, look for a camera with a continuous shooting mode of at least 3 shots per
second; keep in mind that the continuous shooting speeds usually refer to situations with the
flash 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,
2. but usually they significantly reduce the resolution of each photo in order to speed up image
processing and write speeds.
The other forms of shutter lag are important reasons to get some hands-on time with any camera
before you buy it, if possible. Check to see how long the camera takes to power on and snap a
first shot; generally, anything close to a second is considered fast. Another good hands-on, in-
store test is to see how long the camera's autofocus system takes to lock in on a shot after you
press the shutter button halfway. If the camera searches in and out for more than a second,
you'd be better off with another camera for sports or spur-of-the-moment casual shots.
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. Slim 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, 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 less
control over the look and feel of a photo.
Zoom Lens and Image Stabilization
Inexpensive cameras often lack a powerful optical zoom lens, but that's changing. Among the
new breed of $200-range cameras are a few pocket megazooms: compact cameras with optical
zoom lenses as powerful as 10x optical zoom.
If we had to choose between a point-and-shoot 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).
If you're buying a DSLR or a compact interchangeable-lens camera, both the zoom range and
the stabilization features depend on the lens you're buying. A few DSLRs and interchangeable-
lens compacts have in-body image stabilization, meaning that your images will be stabilized by
in-camera mechanics regardless of which lens you attach. If your camera doesn't have in-
camera stabilization features, optically stabilized lenses are available, but they're often a bit more
expensive.
Fixed-lens cameras now offer zoom ratings of up to 36X. These lenses are great for nature or
sports photography, but unless the camera has good image stabilization (look for a camera with
optical image stabilization) or a very fast shutter, 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.
Also note that not all high-zoom cameras are created equal. You know how you have to ask
everyone in your group shot to gather in close to get in the shot? A wide-angle lens can solve
that 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 scene
when you're zoomed all the way out. A good wide-angle lens starts at about 28mm or less on the
wide-angle end; the lower the number, the wider-angle the lens.
3. 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.
RAW Mode
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.
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. 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.
Storage
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.
Battery Life
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.
4. 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.
Exposure Settings
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.
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
5. 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.
Unique Shooting Modes
With the megapixel wars officially over, camera manufacturers are focusing on other ways to
make their offerings stand out from the pack. Some in-camera features are worth the price of
admission alone, and they vary by vendor. For example, Casio has a high-speed shooting mode
in many of its cameras that takes up to 60 shots per second. Nikon has a camera with a projector
in it. Sony has a Sweep Panorama mode that lets you press the shutter button once and then
pan across a scene to create an instant panoramic image. Canon and Olympus both have scene
modes that make large objects look like miniature models, and several companies have cameras
that shoot 3D images. You'll also find quite a few cameras available now with built-in GPS and
mapping features. When it comes to cameras, don't be afraid to dive into the details; you might
discover a cool feature hiding in the spec sheet that makes a camera a top contender for
meeting your needs.
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 the screen is responsive--and 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 an eye-level 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
6. overexposed to the point of being pure white, and shadows that are underexposed and show as
pure black.
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 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
this feature was not worth the extra money it 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. Eye-Fi cards enable
any compatible camera to send photos wirelessly to your computer, to photo-sharing sites, and
even directly to a mobile phone. And TransferJet wireless technology lets you transmit photos
and video between compatible devices simply by holding them close to one another.