Why SLR ???

SLR stands for “single-lens reflex.” The term refers to a type of viewfinder on a camera. A
standard viewfinder is placed beside or above the camera lens and focuses separately from
the lens. The image you see in the viewfinder is never precisely what the camera sees or
what will appear in your photo, although with a well-designed viewfinder it can come very
close.

A typical single-lens reflex camera
A single-lens reflex camera has no viewfinder technically so called. Instead, it uses a
mirror to bend and redirect some of the light from the lens through an eyepiece so that the
photographer is looking right through the lens itself. What you see is exactly what you get.
There are enormous advantages to SLR photography.

The biggest advantage is that an SLR allows you to change lenses in the camera. You can
use a close-up lens, a telephoto lens, and various lenses with different aperture settings to
capture just the image you want. With a viewfinder, this isn’t easy to do, because the
viewfinder is made to match a particular lens and will present a much more distorted
image if you change the lens. With an SLR camera, because the image you see is always
coming from the lens, it’s always true to the lens, no matter which lens you’re using.
SLR cameras are always equipped with a removable lens that can be replaced with other
lenses at will. Sensors are normally built into the viewing display in an SLR camera, too.
They tell you whether there’s enough light at the present aperture setting and shutter
speed, and how well the image is focused. Focusing is much easier with an SLR than with
a viewfinder, as you can see the image as it’s presented by the camera lens and see
whether it’s in focus or not.

All of these are reasons why single-lens reflex cameras have become the standard for
serious photography. That was true long before digital photography became practical (the
first SLR cameras were analog). But today, many of the famous names in manufacturers
of analog SLR cameras have come out with excellent digital SLR cameras, too. These
include Nikon, Canon, Pentax, and others. The advantage of craftsmanship in a digital
camera doesn’t go to the “digital” part (the electronic sensor array and storage routines),
but to the part of the camera that remains analog, with the lens being the single most
important feature.

A single-lens reflex camera of top quality costs more than most other digital cameras.
(That was also true about analog cameras; the SLR cameras were usually more expensive
than the viewfinder versions.) You can expect to pay $400 - $1,000 for a decent DSLR
camera, with the priciest, such as Nikon’s D3X, running as high as $8,000.