How
does a digital camera work?
by Digital Darrel tell
a friend about this article
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WHAT
ABOUT THE ZOOM RANGE OF THE LENS?
Most digital cameras allow you to zoom in
or out to change the perspective of the image. Be careful
of digital cameras that do not have the word "optical"
in the sentence discussing the zoom range.
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| Nikon
8 Megapixel Coolpix 8700 and the 6 Megapixel D100
DSLR |
If your camera
only has a digital zoom, it is not really a zoom. An optical
zoom actually allows you to change the "field-of-view"
of the image, so that you can widen out for a landscape shot,
or zoom in for a portrait. It does this by moving lens elements
to change the focal length of the camera's lens. Some of the
best optical zooms can be as much as 10-to-1 (10x). Most medium
priced digital cameras will have a zoom in the 6-to-1 (6x)
or 3-to-1 (3x) range. Just BE SURE that you're buying an optical
zoom.
In cheaper digital cameras there may be an
attractive "digital" (not optical) zoom range mentioned.
Usually it will be about 3-to-1 or 4-to-1. The problem with
a digital zoom is that it is not a real zoom. The image is
simply being magnified and a section of the image taken out
of the middle. It is the same thing as if you took a film
picture and cropped out everything except a person in the
image, then made a big enlargement. You would then only be
using a small section of the negative, so grain will increase
and sharpness will degrade very quickly. With "digital"
zooms, the image is magnified or cropped electronically and
the image simply has larger pixels. You are not really zooming
in on the subject. Instead, the subject is being electronically
magnified, with image degradation as a result. Stay with an
optical zoom for best results.
Many
cameras come with a combination of optical and digital zooms.
That's okay, since the digital zoom is not used until you
have maxed out the optical zoom. If you really need that much
zoom, though, you might just want to use the old fashioned
"sneaker-zoom" whereby you walk toward the subject
to make it bigger, or away to make it smaller. Or, you could
buy a digital SLR (DSLR) camera and one of those huge long
lenses you see at football games.
WHAT STORAGE MEDIA SHOULD I USE?
(Digital Film)
This varies with the camera manufacturer,
so you are only limited by the specific camera you buy. Many
cameras allow the use of the very common Compact Flash or
CF card. This is a little card about 1/2 the size, and a little
thicker, than a business card. It can hold up to hundreds
or even thousands of images. Other memory types are Microdrives
(MD), Smart Media, Secure Disk (SD), Memory Stick, or even
a floppy disk, or CD.
You
will need to find out for sure just what type of memory card
your camera uses to store pictures. I suggest owning at least
two cards. Most will come with an 8 or 16-megabyte "starter
card," which will hold only a few pictures unless you
set the camera to its lowest resolution. In my opinion, an
absolute minimum for today's cameras is a 128-megabyte card.
You should really try to get a 256-megabyte card, or even
larger if you do more than make an occasional snapshot. The
common sizes are: 8, 16, 32, 64, 128, 256, and 512 megabyte.
Also, you will find 1, 2, or 4 gigabyte cards and microdrives.
The cost for storage cards vary from around $25.00 USD to
over $1,000.00 USD.
The
really inexpensive digital cameras do not provide an external
storage card. They store the pictures in internal memory.
Unfortunately, this memory usually won't hold many pictures,
so you are very limited. Personally, I would not consider
using a digital camera with only internal memory, unless it
was all I could afford.
I
use a couple of IBM® Microdrives with their one-gigabyte
capacity. One of them is equal to eight 128-megabyte cards.
The IBM© Microdrive is a tiny hard drive like the big
one in your computer, but fits into your camera. Only a few
higher-end digital cameras will use the Microdrives though.
The bigger the storage -- the greater the cost. Try to get
a 128-megabyte or even a 256-megabyte card for your camera,
since you will have the freedom to really use your camera
with that much storage. If I set my camera to a lower resolution
setting using JPEG mode, I can put over 1,200 images on a
1-gigabyte Microdrive.
Compact
flash seems to be the most common type of memory card
in use these days, so your costs should be a bit less for
them due to competition.
WHAT CAMERA SHOULD I BUY?
As newer and denser sensor chips are developed
the megapixel rating of cameras will increase, until eventually
we'll have gigapixel, and maybe even terapixel cameras. This
is a lot like computers. Remember back when your home computer
was rated in mere megabytes. Right now the latest computers
are rated in gigabytes, and it won't be long until we have
terabyte computers. Digital camera models change like computers.
They are doomed to obsolescence as the newer and faster cameras
come out. Such is a market society! As this article is being
written several 11 to 14 megapixel cameras are on the market.
The
more expensive digital cameras offer robust camera construction,
"burst mode" shooting that allows you to take a
whole bunch of images in quick succession, and an interchangeable
series of lenses. Many professional photographers use this
DSLR type.
Today,
we have basic "consumer" digital cameras that run
from $200.00 USD to about $900.00 USD. Then, we enter the
arena of the "prosumer" models, which cost from
$900.00 USD to about $2,000.00 USD. Finally, there are the
"professional" cameras, which start at about $3,500.00
USD and run all the way up to about $8,000.00 USD. So, there
is a price range in the digital camera market for about everyone.
As more and more people buy and use digital cameras, the cost
will decrease. Digital seems to cost about 50% more to buy
the camera, compared to film. But, if you shoot a reasonable
amount of images, the less costly image processing will help
pay for the additional cost of the camera.
In
conclusion, buy as many megapixels as you can afford -- two-megapixel
minimum. Check to see that it has an optical zoom. Make sure
that the buffer will hold at least five or six pictures before
transfer to memory card, and get a memory card type that you
can afford.
Keep
on shooting digital pictures!

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