cameras are compact, easy to use, and able to capture a digital
image rivaling film quality, for a price comparable to that of a
standard camera. And you can snap the pictures, load it to your
computer, and have the image on the Web for the world to see in
less than five minutes.
To get the
most from your digital cameras, you need to know the camera's operations
inside and out.
The sensor is the heart of all digital cameras. It's the electronic
chip that takes incoming light and converts it to a digital file.
The density of the sensor determines a camera's overall picture
quality. Most high-quality cameras today use a charge coupled
device (CCD) sensor, while low-cost "entry-level "cameras use
a complementary metal-oxide semiconductor (CMOS) sensor, CMOS
chips are easier and cheaper to make.
Resolution refers to the number of pixels in a picture. Pixel
stands for "pictures elements", and it is the smallest part of
a recorded image. VGA (Video Graphics Array) digital cameras are
typically the least expensive cameras. The small sensor in a VGA
camera captures just 300,000 pixels. These pixels are arranged
in rows and columns. A VGA image 640 rows and 480 columns of pixels,
hence a resolution of 640x480. XGA (Extended Graphics Array) and
1-megapixel cameras capture between 700,000 and 1.3 million pixels.
Settings: Compression is shrinking the file size of a captured
image down to a more manageable size. Some cameras will let you
save in both the JPEG and TIFF format. TIFF photos require more
storage, but they are higher quality. If you have a lot of memory
in your camera or if you plan on having your photos professionally
Digital cameras hold photos in internal memory (generally a few
megabytes of memory) or on removable media (small cards that go
in and out of a slot in the camera and hold many megabytes of
photos). With internal memory, once you've filled it up, you have
to either download your images to a computer to continue shooting,
or delete the images from the camera. With removable media, you
just take out the full card and slide in a new empty one.
Crystal Display (LCD): A liquid crystal display (LCD) is the
color, television-like display on the back of a digital camera
that allows you to see and frame the picture you're about to take.
With an LCD displa, you don't have to read and interpret a light
meter or guess at exposure settings: You see how your shot's going
to come out before you snap the picture.
This is in many ways the most important part of the camera for
one simple reason- any scene or subject that a camera photographs
must first go through the lens.
It is like a curtain over a window. When it is open, light comes
into the lens and hits the camera's internal sensor. A camera
with a fast shutter can capture fast-moving action, such as a
runner in a soccer game or a hummingbird's beating wings. If the
camera's shutter opens and closes too slowly, then your action
scene will be blurred. A camera's shutter speed is measured in
thousandths of a second.
It is shrinking the file size of a captured image down to a more
manageable size. Most digital cameras use some kind of compression.
An uncompressed image can be very large (between 8MB and 16MB),
and since this is not practical (except on very expensive professional
digital cameras), some form of compression needs to be applied
to the image. The most universally accepted compression algorithm
is joint photographic experts group (JPEG). The JPEG algorithm
analyzes an image and throws out data that it thinks is nonessential
to the picture. It doesn't throw away important details like buildings,
people, or landscapes, but it does throw out the data that can't
be perceived by human vision.
It's the fastest and easiest way to connect your camera to a computer
and transfer images to its hard drive. Most, if not all, digital
cameras today ship with a USB port.
Most digital cameras have a built-in flash that has a range of
about eight feet. The flash normally has multiple modes of operation.
These settings include: off, automatic, always on, flash fill
(evens out a scene's lighting), slow sync (illuminates the foreground
while letting the natural background light come through), and
red eye (eliminates the glowing red pupils that sometimes occur
when a flash goes off in someone's face).