Setup guide

DIGITAL CAMERAS
THE BASICS
DIGITAL CAMERAS
10
For Any Inquiries Regarding Your Order, Call Our Customer Service:
[phone] • [phone] • FAX: [phone] • [phone]
Pixels = Resolution
One of today’s hottest buzzwords when buying a digital camera is
“megapixel”— and for a very good reason. Let us explain. At the
heart of every digital camera is the electronic sensor (usually CCD)
that records the image. The sensor is composed of thousands of
microscopic dots called picture elements, or “pixels” for short (“pix”
for picture, “el” for elements). And yes, you guessed it — the more
pixels an image has the better its resolution, and the more detail it
will have.
Simply put a “megapixel” is a million pixels. A one-megapixel
digital camera, at its maximum quality setting, produces images
composed of approximately 1,000,000 individual pixels. This is
also described by an equation showing the amount of pixels laid out
horizontally and vertically on the CCD. For example a camera with
1152 x 864 pixels means it has 995,328 pixels. Similarly, a
two-megapixel camera will usually have a spec of 1600 x 1200
(1,920,000 pixels), and so on.
So what is the point of this exercise? Well, resolution is important
because to get large images that equal conventional photo print
quality you need a certain amount of pixels. Otherwise, you’re
pictures will become jaggedy and pixelated. So in determining how
many pixels you need, you first have to decide what size prints you
want to make. The rule of thumb for printing digital images is that
you need 300 dpi (dots per inch) for top image quality. So for exam-
ple, you want to print 5 x 7’s you would need something in the area
of a 3.3 megapixel camera. Why? Divide for example the 3.2 megapix-
el (2048 x 1536) resolution of the Canon PowerShot SD100 Digital
Elph by 300 (dpi) and you get 7.13 x 5.2. Now of course this is only a
rule of thumb. You can easily get away with 240 dpi and a photo-
quality inkjet printer. And if you’re careful about how you save the
image (using TIFF, RAW or low compression JPEG files) you can actu-
ally print larger images by increasing the size of the files through
software. So depending on your personal standards—what one view-
er considers fine, another might find unacceptable.— a good 8 x 10˝
print can come from a two-, three- or four-megapixel file.
Now the other side of this, maybe you just want to take pictures for
posting on the web, to put on CDs, or e-mail to friends. There your
requirements would be much lower. For the web you only need 72
dpi—a full 75% less resolution than high quality print. So obviously,
you’d be able to get away almost exclusively with a 2-megapixel
camera. (However you will get much better quality with a camera
that offers better optics—even at 72 dpi). And if you want all the
options (shoot high and low quality), you should look for a camera
that offers several different shooting resolutions. This way you won’t
lock yourself into shooting 5MB files when all you need is 1MB.
The Lens
When you are in the upper deck of a ballgame, nothing comes
in more handy than a good zoom lens. Nine out of ten cameras
today come with a zoom, and the only reason not to get a cam-
era with a zoom lens would be cost. So when you look for a
camera with a zoom, the only thing you have make sure, is,
that the lens is an optical zoom and not a digital zoom. Optical
zooms let you change the focal length just like conventional
35mm zoom lenses. A digital zoom though, takes a smaller
image captured on the CCD, crops it and then enlarges it (basi-
cally by duplicating every pixel). Better digital systems use
interpolation, an algorithm that averages two adjoining pixels
to create the new extra pixel
Changing Focal Lengths
When looking at a lens’ focal length, you should remember that
the CCDs in digital cameras are much smaller than a 35mm film
frame. 35mm cameras capture light in a frame measuring 24 x
36mm or roughly 1 x 1.5-inches. But CCD chips are much small-
er (in some cases 1/3 or 1/2 an inch.) So focal lengths will be
much smaller. To help you determine what kind of zoom lens
the camera has, most manufacturers (and we have also in this
catalog) provide you with the focal length in “35mm equiva-
lent”, and that is the length you should go by.
On the flip side of this, putting a 35mm lens on a digital SLR-
type camera will also skew the focal length—but this time by
multiplying the focal length, usually by a factor of 1.6x. That
means a 100mm lens on your 35mm SLR will be 160mm on a
Canon EOS 10D.
Getting back to point and shoot type digital cameras, 2x and 3x
are the most common optical zoom lenses. A 3X means three
times from the widest to the longest lens setting (for example,
35mm to 105mm). Some cameras come with longer lenses, a
10X for example. However, be aware that as the lens gets
longer, it gets harder to hold the lens steady enough while the
picture is being taken. The camera will have to feature an
image stabilization system or you will need a tripod.
The last thing you’ll want in a lens is macro (close-up) capabili-
ty. This is the ability to focus on objects that are very close to
the lens. Even with a zoom lens, if you want to take a close-up
of an object, and the lens won't focus closer than four feet, you
won't be able to fill the frame with a postage stamp. With good
macro ability you can literally get within inches of an object—
so you can fill the frame with that stamp, coin, bug, etc.
Choosing a Digital Camera—What You Need to Know
Choosing a digital camera doesn’t have to be difficult. You just need to understand what you'll be using the camera for and
then learn the basics about what makes these incredible image making tools “click”. After spending a few minutes on these
pages you should be able to wade through the maze of choices and make an informed decision. Of course if you still need
more help, feel free to call us and speak to one of our experienced digital camera experts.