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.