|
Thinking of Buying a
Digital Camera?
Digital cameras are fast
displacing film cameras
because of the immediacy, convenience and economy that digital
photography
offers. Although digital images still
fall short of the best film images, they are quite adequate for
everyone except
demanding professionals. In fact, to
most of us there is no discernable difference. However,
not all digital images are equal, and the major
factors that
determine their quality are in the camera you use. The
two
features most touted in ads for cameras are the number of pixels and
the amount
of zoom. Pixels (short for “picture
elements”) are the
individual tiny pieces that make up a digital image.
The more pixels a camera has, the higher the
potential resolution (i.e. sharpness) of the images it produces. And in turn, the higher the resolution, the
bigger you can make the final print without it looking indistinct. Consumer-grade cameras (as distinguished from
professional grade) typically have at least 3 megapixels these days. That’s enough to support enlargements of
8”x10” and sometimes even more. In fact,
if you are sure you’ll never want
anything bigger than a 4”x6” print, or that you will only use the
images in
Email, then even 2 megapixels could be adequate. “Zoom” is the range of
magnification available to
you. A zoom range of, for instance, 3:1
means that if you set the lens at the maximum point of the range, the
scene is
brought 3 times closer than at the minimum point. We’ll
have more to say about zoom below.
The
camera lens
A
poor lens will blur a picture no matter how many pixels the camera has. You’re more likely to get a good lens in a
camera from a well-established firm such as Canon, Nikon, Kodak,
Minolta and a
few others.
Most digital cameras have zoom lenses. There are three zoom numbers that may be
quoted in any given ad: Optical zoom,
digital zoom, and total zoom.
IGNORE
“digital zoom”: So-called digital zoom is
achieved by
internal cropping of the picture. That
is, the camera uses only a part of its sensor and then transmits that
partial
image as the whole picture. The result
looks magnified, but it’s just the result of spreading fewer pixels
over the
same area. It’s not real. “Total
zoom” includes both optical zoom and
digital zoom, so ignore total zoom also.
Optical
zoom is the only figure that represents the real zoom capability of the
camera.
Supporting
software Un
Unless you take the
camera’s memory card (its
reusable “film”) to a photo kiosk or other photoprocessing outlet, you
will be
downloading the images to your computer, which is to say that you’ll be
copying
the images to the hard drive. The
downloading is done via software that comes with the camera. The camera will probably also come with
software that will enable you to make adjustments to the picture. It might let you determine how much to
compress (that is, “squeeze”) the image file in order to save storage
space and
speed transmission through the Email. Good
software will have the capability of adjusting things
including
brightness, contrast, vividness of the color, and possibly other
characteristics, as well as to remove the “red eye” so often seen in
flash
pictures.
If
you’re serious about working on the images,
you can buy image-manipulating software separately, that will have
additional
capabilities. For instance, it could
enable you to remove blemishes from people’s skin. If
you print your own pictures, using
your computer’s printer The
quality of the printer is important. Although
you don’t need a printer designed specifically
for photos, you
do want one with good printing resolution. Look
for at least 2400x1200 dpi (dots per inch). The
paper is also important. You can make
passable prints on ordinary paper, but photographic paper will give
results
like those you would get from a photoprocessing laboratory. Choose glossy paper.
If you
want to keep the prints for a long time, pay attention to the ink
cartridge you
use in the printer: Cheap inks dry
slowly and fade relatively quickly over time.
There are other factors
influencing image quality, but
the ones mentioned above are the most significant ones for everyday
photography.
In
addition to
the features discussed above, there may be others that appeal to you,
such as
the size of the on-camera display or the ability to take several
pictures in
rapid succession. Those are matters for
a much more detailed article, such as the review in the May, 2004 issue
of
Consumer Reports. Two
last bits
of advice: (1)
When
looking at (and trying out) cameras in the store, don’t judge picture
quality
by the little display on the back of the camera: Images
that look fine at a size of 1.8” can
look terrible at 4x6. (2)
Realize
that as the technology continues to advance, progressively better
digital
cameras will become available and prices will continue to drop. Today’s top-of-the-line camera is tomorrow’s
entry level model. That is the way of
all digital technology, so don’t feel bad when you buy a digital camera
only to
see several months later that a more advanced model has appeared,
possibly even
at a lower price. If you were to buy
that one, you would have the same disappointment six months or a year
after
that. So buy one when you’re ready to go
digital, and enjoy it. W. A. Shapiro |
11/5/04-2125