by: Roy Barker
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.
One major factor determining the choice of
camera is weight. Typically the SLTD camera is half the weight
of it’s SLRF counterpart. The point and shoot is fully
automatic, but like their counterpart the idiot proof they do
not give the photographer much creative control. They have
earned their stripes, on the occasions when a photographic
opportunity would have been missed with SLRF. The middle of the
range family of digital cameras represent the fastest growing
demand for new cameras as they represent the ease of digital
with a higher level of creative control. You can also make
larger prints, as well as use the function of through the lens
focusing. The higher resolution top of the range digital cameras
offer the same wider exposure controls and the ability to use
different lens, in other words they offer the best of the
features of analog photography to digital photography. The most
recent development in digital cameras has been the development
of a standard image sensor in the ratio of 4:3. As the image
sensor has a standard size and shape, the mount for the lenses
can be identical. That means that they will fit more than one
type of camera, and will ultimately be cheaper to produce, as
they can be produced in higher volume. Canon lenses for SLR film
only fit Canon cameras, but they will now disappear. In future
to add to the growing confusion, there will be a plethora of
lenses from multiple manufacturers, to fit your camera,
competition between the lens manufacturers should mean cheaper
and better quality lenses. One factor not to be forgotten in
deciding whether or not to go digital, is that the quality of
the lens is still of paramount importance, it is still better to
have a cheaper body and higher grade lens.
Another major element is that digital image
sensors are smaller than frames of film, which means that the
lens can be correspondingly smaller and lighter. Until the
development of the 4:3 ratio systems, digital cameras used
conventional lenses. Getting the most from your camera? - click
here
The type of digital camera to choose is as
complex as buying a car, it is a matter of personal choice,
dictated by what it is used for, and the available amount of
money to spend. Fortunately there is a large amount of help in
this respect already available on the Internet for you to
research. At imaging resources you will find a large database
dealing with individual camera models, the reviews also cover
the scanners and printers as well. It includes member’s forums
to assess individual comments as opposed to manufacturer’s
claims. To review the cameras by make and price there are Canon,
Fuji, Kodak, Minolta, Nikon, Olympus and Sony. One of the major
drawbacks of using digital film, was that the quality of prints
produced on a personal computer’s printer was less than
satisfactory. This obstacle has been overcome by the development
of online printing centers. You upload the film to them via e-
mail and they print the images and they are returned by post,
with a professional standard. Kodak gallery offers you the
opportunity to have your images improved and printed, and then
to share your album via your computer, which means that your
personal scanner is not necessary. Luminous Landscape has an
excellent article on color to improve the final color of images. |