Types of Photo Cameras
The primitive cameras were merely pinhole or box cameras. They featured only a very tiny hole in front where light could enter and a sheet placed on the opposite end with light-sensitive coating, which formed the image after application of some type of chemical. Soon afterwards, crude lenses were devised and installed on the front hole for better control of the entering light. Today, there are still some international circles or clubs producing images with these cameras as an art form.
Take a Picture
Later, view cameras were invented to photograph not only personal and family portraits but also landscapes and seascapes. This kind of camera allowed the photographer to achieve very sharp focus. It used a lens at one end of bellows or extendible chamber on a movable rack, and at the other end it had a chamber to receive interchangeable film plates of varying sizes. The advantage of this camera was that, when necessary, the photographer could alter the angles of the lens and the film plate relative to each other—that is, not at parallel angles. Using nonparallel lens and film angles was found to correct distortion of the vertical and horizontal parts of buildings and structures in photographs. Today, this concept is still being used, especially in expensive digital view cameras for architectural purposes.
Soon, the convenience of multiple-exposure roll film became popular, replacing sheet film. A little further along, Kodak Instamatic cameras were introduced and became well-liked for their ease of use, which was the result of using convenient film cartridges instead of cumbersome rolls of film. Next, the demand for instant results led to the development of Polaroid cameras. This kind of camera used no film but only photo paper that needed no developing. The final image was formed on the paper in only a matter of minutes while inside the camera right after the shot is taken. Fixed-focus lenses were used and people didn’t need to bother about focusing since all pictures were reasonably sharp.
More serious photographers soon used more and more sophisticated cameras using multi-element, multi-coated and colour-corrected lenses. They used new film technology, featuring improvements such as finer grain for sharper pictures and higher speed or sensitivity for better-exposed images. These cameras ranged from compacts and twin-lens reflex cameras, which used two separate lenses for viewing and photographing a scene, to more costly single-lens reflex cameras (SLRs) that used the same lens both for viewing/composing and photographing the scene. The SLRs made it practical to use interchangeable lenses, from wide-angle to telephoto lenses and zooms, which allowed photographers to use the same lens for shooting wide-angle panoramic images as well as for bringing distant subjects closer (as though using a telephoto lens). Many professional photographers still use these kinds of film cameras because current film technology allows blowing up images to movie-theatre-screen sizes without losing detail or sharpness.
Olympus Camera
The current generation of cameras uses digital technology, and this has made photography more accessible and hugely popular. Instead of using film, these cameras use a sensor, which is either a charge-coupled device (CCD) or complementary metal oxide semiconductor (CMOS) to receive the image that is viewed through the lens. Each picture is recorded as millions of pixels (picture elements) in either the camera’s built-in digital memory or on a removable memory card. A whole lot more pictures are possible on a memory card than with a roll of film, and because it is possible to view a picture on the built-in LCD (liquid crystal display) screen or viewfinder, one can delete unwanted pictures at one’s convenience. Selected images can then be copied easily onto a computer or cellular phone memory for later printing or sharing with others as e-mail attachments or multimedia messages via cellular phone. In practically all cases, automatic focusing is featured, which enables composing and focusing even in low-light situations. In addition, some cameras allow infrared focusing and photography, such that one can shoot even in total darkness.
Digital camera technology has now spilled over into other product applications such as video cameras, cellular phones, desktop and laptop computers equipped with webcams, spy and surveillance cameras, and special cameras used in medical endoscopy and submarine or underwater exploration. Of course, this is the same digital technology used in U.S. and Russian spacecraft that transmit images of the planets they have been sent to orbit or land on.