Most serious photographers and professionals use a Single Lens Reflex camera (SLR),
the definition of an SLR camera is that the image is captured exactly as you see it
in the viewfinder. However there are now two types of SLR the single lens reflex film
(SLRF) and the single lens digital (SLRD). They are both single lens camera, but
digital does not use film and the resulting image can be processed at home with the
aid of a photographic editor such as Photoshop.
The chemical component in a traditional camera is film. When film is exposed to a real
image, it makes a chemical record of the pattern of light, coming through the lens.
Film has a collection of light sensitive frames, suspended on a strip of plastic.
Colour film has three different layers of light sensitive material, which respond to
red, green and blue (known as the (RBG) values. When the film is developed, it is
exposed to chemicals, which dye the separate layers of film, into a colour negative.
All modern film is made up of silver halide crystals.
The digital revolution is the conversion of analog information, which is represented
by a gradually fluctuating wave, to digital information represented by bits. This
shift in technology has revolutionized both visual and audio information, in the form
of cameras, televisions, and MP3 players. Whilst SLRF cameras relied on a chemical
process to transmit an image onto film, all digital cameras have their own inbuilt
computers, which records images electronically.
Essentially the digital camera represents a form the computer can understand, the
information is collected in bits and bytes. Each part of the image is broken down
into "pixels", which is a contraction of picture element. When monitors display
colors they are arranged in rows and columns, separated into thousands of little
squares of colour. They are so minute that they appear to be connected, but if you
zoom into this the squares are quite separate. All these squares are the smallest
dot that can be displayed by a monitor, and combined together they display the completed image.
Because of the enormous difference in the way the two types of camera work, there
has been in many people's mind a huge confusion as to what type of camera to buy.
Added to that there are three types of SLRD cameras. SLRF cameras had conventional
shapes, because it was necessary to have room for the film, and the light path,
SLRD cameras do not have these constraints.
At the lower end of the market for the digital cameras are the "Point And Shoot",
their SLRF equivalent is known as "idiot Proof". They have low resolutions of
between 3,000.000 and 4,000,000 million pixels. The next level is the proconsumer
camera typically with a resolution of 4-5 million pixels. At the top end of the
market the resolution is between 6-12 million pixels. The greater the number of
pixel resolution the better the quality of the resultant image.
As with any new technology there are 'pros and cons' with both types of cameras,
and it will be decades before digital cameras replace SLRF, if indeed they ever do,
more likely the SLRF cameras will be retained for use in a specialist market. It
is also fair to say that the quality of digital cameras has improved enormously
in the last ten years, and the price has also reduced dramatically.