There are several different types of digital cameras, if you understand
the methods used in the camera's design it will help you chose the right one
for your particular use.
The camera system can also have several parts that are important.
Aperture range
Focal lengths
Illumination alternatives
Tilt and swing alternatives
Shutter speeds
Portability
Battery life
All of these qualities must be considered when choosing a digital camera.
A digital camera captures an image through a sensor called a CCD. This
sensor has light sensing dots called pixels. The actual resolution of a
camera is the total number of pixels that are located on the CCD sensor.
Resolutions of digital cameras range from (0.3 megapixels to 5+
megapixels). A megapixel is just a way of expressing how many pixels are on
the CCD sensor, in millions. Thus, a 2-megapixel camera has 2 million pixels
on the cameras CCD sensor.
Maximum size an image may be (measured by height x width) for the three
most popular types of digital cameras on the market today.
2-megapixel digital cameras - 1600x1200
3-megapixel digital cameras - 2048x1536
4-megapixel digital cameras - 2272 x 1704
But remember, a 2-megapixel camera might produce the same quality
photos as a 4-megapixel, but the 4-megapixel
will produce a larger image.
However mostly the higher the megapixel rating on the camera, the
better it has been constructed, and therefore produce better quality photos.
Memory
A digital camera stores all of the photos it takes on a memory card.
Compact flash card
Smart Media cards
By far the most popular and least expensive is the Compact flash. Memory
cards come in different sizes, generally the larger they are the more photos
they will hold. However the amount a particular cameras memory card will
hold will depend of the size of the photos and compression.
Compression
Compression is how much the digital camera compresses an image. When a
digital camera takes a picture, a very large file is created . In order to
fit more images on a memory card, digital cameras compress these image
files.
The camera might have different settings like Small, Good, Fine or best
all will produce a photo that has a different quality, and different photo
size. The cameras resolution setting will also influence the quality of the
final picture.
The more expensive digital cameras will have their own LCD display, which
you can preview the picture on, or view what you are about to take a photo
of, but be aware that these displays also take more power, and the cameras
battery wont last as long as it would without previewing.
Lens
Another important part of the digital camera is the lens, no matter how
good the rest of the camera is, if it has a poor lens it wont take good
pictures. Modern digital cameras might come with zoom lenses, which allows
you to adjust the length of the lens to either move closer to the object or
further away.
Digital cameras usually come with two types of zoom on them.
The first is the optical zoom which is identical to that found on
traditional cameras. When using optical zoom, you can get closer to a
particular object without any sacrifice in image quality.
Digital zoom, however, is a new type of zoom that is found only in
digital cameras. When using digital zoom, the camera itself modifies the
image electronically to bring the object you are photographing closer to
you.
Flash
Make sure the digital camera has one, else it wont be able to take good
photos in dark conditions. Numerous flash modes are available on digital
cameras. The four important flash modes are
Automatic, The digital camera sense when to use the flash according
to the lighting conditions.
On, The digital camera will use the flash for every picture.
Off, The digital camera will never use the flash.
Red Eye Reduction, This is needed if you plan on taking pictures of
people, pets or wildlife.
Connecting the digital camera to a pc
Although its not necessary to have a computer to use with your camera, it
makes a big difference. You could take the memory card along to a
photographic shop to have the photos printed. If you have a Personal
Computer you can upload your photos to it, then are able to edit them, make
up a disk with your best ones, and even print your own photos.
USB
When choosing a digital camera, its best to get one that has a USB
interface, older cameras use to use the old RS232 or printer port, there is
much less trouble using the computers USB port make sure your PC has one,
most modern PC's have 3 or more USB ports.
Batteries
Always check how long the batteries will last, there are digital cameras
that produce very high quality pictures, come with a LCD view screen but the
batteries give up after taking 30 photos, I guess that's not bad considering
the old film produced about the same amount. However digital cameras can
take 300 pictures and more, so check the specification on battery life.
