 |
in
a digital camera |
|
|
|
|
| Basic camera components |
| |
 |
 |
Lens |
 |
Many digital cameras are equipped with a 3X optical
zoom lens, and some provide as much as a 6X or 10X zoom. Don't put too much stock
in digital zoom, which is a software feature that has nothing to do with the lens.
It merely enlarges a small portion of the image at the expense of picture detail.
If you'll be doing a lot of low-light shooting, look for a fast lens--that is,
a lens with a maximum aperture setting of f-1.8 or f-2.8. The lower the f-stop,
the faster the lens and the more you'll be able to capture in low light. Most
consumer digital-camera lenses are permanently attached to the camera body, but
many are compatible with wide-angle, close-up, telephoto, or even fish-eye attachments.
If you want to use a lens shade or a filter, make sure that the camera lens is
threaded so that you can attach it. Some advanced digital cameras are compatible
with 35mm film-camera lens systems, letting you choose the lens that's most appropriate
for your subject. |
 |
| Sensor |
 |
Once light passes through the lens of a digital camera,
it's captured by a CCD or a CMOS sensor. The sensor is covered with photosensitive
pixels (short for picture elements); the more pixels on the sensor,
the higher the sensor resolution. And, of course, the higher the sensor resolution,
the higher the resolution of the images captured by that sensor. Higher-resolution
images are sharper and show more detail, but they also require more storage space
and can quickly fill a camera's media. Casual snapshots look fine at 640x480 pixels
when displayed onscreen. But if you want to print your photos or crop them to
highlight particular areas, you'll need more than 1 megapixel to get adequate
image quality. The resolution you need in an image increases with the size at
which you want to print it. If you want to enlarge your photos to sizes greater
than 5x7 inches, you probably won't be satisfied with the results from a sub-2-megapixel
camera. |
 |
| Media |
 |
Unless you're purchasing an inexpensive digicam that
has internal memory only, you should expect to find some type of removable image
storage medium when you open the box. When you press the shutter-release button
to take a shot with your digital camera, the image that the sensor captures is
saved on the storage medium. There are many types of media for digital cameras,
but most models are compatible with only one. The most common are CompactFlash
and SmartMedia. Many Sony cameras use Memory Stick and some use mini-CDs or floppy
disks. MultiMedia Cards (MMC), IBM Microdrives, and some proprietary media types
are also used. Make sure you get a camera that is compatible with the type of
media that offers enough storage space to meet your needs. Most types of media
are available with a range of capacities--and prices--and you'll probably want
to purchase extra media with a greater capacity than what's included with your
camera. Check out our feature on
media options to get a handle on which type is best for you. |
 |
| Viewfinder and LCD |
 |
Most digital cameras have an optical viewfinder that
works just like the ones on film cameras: hold it up to your eye, frame the scene
you want, and shoot. If you wear glasses, look for an optical viewfinder with
a diopter so that you can adjust the viewfinder focus. If you're buying a camera
that costs more than a couple hundred dollars, you should expect it to have an
LCD screen too. This usually serves as a viewfinder, an image-playback screen,
and a display that gives you access to camera features and functions through a
menu system. Look for a sharp LCD that shows a clear image in both bright and
dim light. Some cameras let you adjust the brightness and backlighting of the
LCD, which is helpful. An LCD is usually located on the back of the camera, and
some can be folded out and swiveled, much like the ones on video cameras. Another
similarity to video cameras can be found in digicams that use electronic viewfinders
(EVFs) instead of optical ones. You hold the camera up to your eye and look through
an eyepiece to use an EVF, but the image you see is just like the LCD image. If
you buy this kind of camera, give the EVF a look first to make sure that the display
isn't jumpy when you zoom and pan. |
 |
| Batteries |
 |
Every digital camera should ship with alkaline, lithium-ion,
or nickel-metal-hydride batteries. Alkaline batteries are convenient because you
can buy them anywhere, but they don't have as long a life as other power sources.
Cameras that use longer-lasting, rechargeable lithium-ion or nickel-metal-hydride
batteries should also come with a charging module. Some cameras can use more than
one battery type, which gives you both the convenience of alkalines and the longer
life of rechargeables. Most cameras also come with an AC adapter so that you can
save some battery life while shooting indoors or downloading photos to your computer.
If an adapter isn't included with the model you want, it's a good idea to buy
one separately. Whatever battery you end up with, be sure to have enough spares
when you take your camera on the road. |
 |
| Flash |
 |
Shooting under low-light conditions can be tricky,
so you'll need a reliable built-in automatic flash. Look for a camera that offers
red-eye-reduction flash for shooting people and animals. Other helpful features
are forced (fill) flash, slow-sync flash, and adjustable illumination levels.
Twilight-scene modes generally use a slow-sync flash to illuminate a subject in
the foreground of a dimly lit scene while capturing adequate detail in the background.
If you need more power and flexibility from your flash than the built-in unit
gives you, you may want to purchase an external flash unit. Only cameras equipped
with a hotshoe or contact are compatible with off-camera flashes. Some manufacturers
offer dedicated units that are designed to work with particular camera models,
but if there's no recommended flash unit for your digicam, you can find a wide
range of flash units available from better photo-equipment retailers. |
 |
| Popular
camera features |
 |
 |
Exposure modes |
 |
Every digital camera has a fully automatic mode that
lets you simply point and shoot. Program auto-exposure modes keep the basic exposure
settings automatic while giving you manual access to other camera settings. If
you want more control over exposure, look for a model that offers aperture- and
shutter-priority modes, which let you set the f-stop or shutter speed, then automatically
calculate the other settings needed to expose your image correctly. For total
control, look for a full manual exposure mode.
Many digital cameras offer exposure compensation. This feature allows
you to make adjustments to the automatic exposure setting in situations where
the camera's light meter might have trouble. For example, if you're shooting a
person against a bright background, the person might come out looking very dark
in the picture. That's because most of the area that the camera's metering system
read to calculate the exposure was much brighter than the person. By using exposure
compensation, you can correct the settings so that your subject gets enough light.
Some advanced cameras offer automatic exposure bracketing. This feature
shoots several frames when you release the shutter, each at a different exposure
setting. You can then choose the one with the exposure you like best. |
 |
| Macro mode |
 |
If you like taking close-up shots or photographing
small subjects, such as wildflowers or insects, you'll need a camera with a macro
mode. Look for one with a minimum focus distance of less than five inches if you
really like to get in close. |
 |
| Continuous-shooting or
burst mode |
 |
Attaining fast enough shooting speed has been one
of the biggest hurdles for digital camera makers. Early digicam users can attest
to the frustration of waiting around for their cameras to save one shot to the
memory before they could shoot the next one. Recently, shot-to-shot times have
gotten faster, and shutter lags--the pauses between the time when you
hit the shutter-release button and the moment the shot is captured--have decreased.
But capturing fast action can still be tricky with a digital camera. One way manufacturers
have dealt with the problem is by offering burst or continuous-shooting
modes. Like a motor drive on a film camera, continuous-shooting mode lets you
capture several photos in very quick succession. When it's done shooting, the
camera usually takes a long pause to save all those images to the memory, but
continuous shooting is still a useful tool for photographing subjects in motion. |
 |
| Scene modes |
 |
Many digital cameras offer special modes that optimize
the camera settings for specific types of scenes. Landscape, portrait, twilight,
and pan-focus are among the most common scene modes. Scene modes can affect both
exposure and focus settings, and a panorama mode lets you shoot a scene in several
frames, then "stitch" them together to make one big picture. Look for
a camera that offers scene modes that correspond to your favorite photo subjects.
If you think you'll use this feature a lot, make sure that the camera you buy
gives you easy access to it through a button or dial, instead of making you hunt
through the LCD menu to find it. |
 |
| White balance |
 |
All digital cameras offer an automatic white-balance
setting that allows the camera to calculate the right color balance for your shot.
Many models also let you select among white-balance presets that are calibrated
for particular types of lighting, such as sunny, cloudy, incandescent, or fluorescent.
If you're going to be doing a lot of shooting under fluorescent light, look for
a camera with presets for all three types--or at least make sure that the fluorescent
setting on the camera you choose matches the type of fluorescent light you'll
be using. Manual or custom white-balance controls let you take a reading from
an area that you want to appear as pure white in your picture, then use that reading
to calculate the color balance. Some advanced cameras also offer white-balance
bracketing or let you adjust the red, green, and blue color channels separately.
If you're using studio lighting, you might want a semipro camera that provides
white-balance presets labeled by color temperature instead of lighting type. |
 |
| Video and audio modes |
 |
If you're serious about shooting videos, stop reading
right here and go look for a dedicated
video camera. The resolution and features available for video capture on digital
still cameras just can't compete with what you get from a camcorder. That said,
if you're not planning on sending your next clip to Sundance and just want to
have some fun, there are lots of digital cameras that are ready to accommodate
you. Some cameras record silent video only or save only short clips. If you want
to get the most motion-picture power out of a still camera, look for one that
captures sound with the video and offers an extended video mode. Extended modes
let you shoot as much video as your media will hold. Some cameras offer audio
modes that let you annotate still shots with brief recordings or use the camera
as a voice recorder. |
 |
| Service
and support |
 |
 |
Warranty |
 |
A one-year warranty on parts and labor is standard.
Many retailers offer three- and five-year extended warranties from Mack Camera
and Video Service. Although most problems with digital cameras will become apparent
before the standard warranty runs out, if you're risk-averse or are purchasing
a pricey model, you might want to consider purchasing an extension. But make sure
you understand the terms before handing over your credit card; some parts of the
camera--such as the lens and LCD--aren't covered by Mack warranties. You can take
a look at the fine print yourself on
Mack's Web site. |
|