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→Types of cameras
The era of the hand-held camera didn't last long, though. In the mid-1990s the first digital cameras had appeared. Dispensing of film entirely, these new cameras were convenient, able to be plugged into a computer, and by 2000 were being attached to cell phones. Partially because of this many camera-makers - Polaroid and Kodak among them - have declared bankruptcy.
The era of the hand-held camera didn't last long, though. In the mid-1990s the first digital cameras had appeared. Dispensing of film entirely, these new cameras were convenient, able to be plugged into a computer, and by 2000 were being attached to cell phones. Partially because of this many camera-makers - Polaroid and Kodak among them - have declared bankruptcy.
==Parts of a camera==
===Shutter===
Within the camera is a device called the shutter, which is a light-tight, mechanically movable element which lies in front of the film or electronic sensor. When the photographer takes the picture the shutter opens, allowing light to hit the film or sensor for the duration of the preset shutter speed. After exposure, the shutter closes and protects the film or sensor from unwanted light, and will open again during the photographer's next attempt.
Compact, medium format and large format cameras usually have a central, or leaf, shutter with resilient curved slats that open radially for the duration of the exposure. The central shutter can be located in the camera body or inside the lens between the front and rear lens groups. In film-based cameras such as SLRs the focal plane shutter is located in the camera immediately in front of the film plane in the housing. For exposure, it opens similar to a double-curtain in some models or creates a slot in others; both have variable width which is determined by the exposure time. The longer the exposure time, the wider the slot. Some single-lens medium-format SLRs with central shutter lenses also have an additional focal plane shutter which is not meant for image exposure, but only as an aid or auxiliary closure to protect the film from light when focusing or changing a lens.
In the early days of photography exposure times of several minutes, but at least several seconds were required, with the "shutter" simply being the lens cap removed and replaced by the photographer during the exposure time. Prior to the advent of digital cameras, film SLRs have mechanically controlled shutter speeds up to 1/1000 second for focal plane shutters, and up to 1/500 second for the central shutter. The shortest purely mechanical shutter speed is 1/4000 second for the Nikon FM2 of 1982-2001. Longer shutter speeds in the low second range can be found in older cameras with the self-timer mechanism. With electronic shutter control by means of electromagnets and control electronics, modern 35 mm cameras achieve the shortest shutter speeds of 1/12,000 second (Minolta Dynax 9xi and Dynax 9) and system cameras (Olympus OM-D E-M1 Mark II) even of 1/32000, but also automatically controlled times up to 30 seconds and longer are feasible.
===Lens===
The image-forming device that is the main portion of a camera is the lens, and depending on the camera consists of one to as many as 12 elements. The first cameras were fitted with a single lens consisting of one convex and one concave surface, called a ''meniscus'' lens; as camera design improved, so did the lens, and the single lens element was placed within inexpensive pocket cameras where it did produce satisfactory results for amateur photographers.
The three basic types of lenses which evolved beginning in the early-20th century were wide-angle, normal, and telephoto.
====Wide-angle====
Wide-angle lenses are used to present as wide as possible the image being taken, such as getting a famous bridge in one shot for illustrative purposes, or to photograph the interior of a house for sale. Such lenses are also categorized into three types: "fisheye", ultra-wide and simple wide-angle. "Fisheye" photographic lenses cover an angle of 180° and greater, while the deformation they create is excessive. The ultra-wide-angle photographic lenses have a viewing angle of from about 100° to about 85°, the deformation they cause is easier to control than "fisheye". Wide-angle photographic lenses have a viewing angle of approximately 90° to 60°, their distortion being small, approaching the perspective found in normal lenses.
====Normal====
Normal lenses have a viewing angle of approximately 55° to 35°. These lenses are the most common and are particularly useful for generic photos and photos under low light as they have a large aperture.
====Telephoto====
Telephoto lenses are used primarily to bring into focus an object which is otherwise unobtainable due to distance, such as a faraway building or wildlife. They have a viewing angle of 40° to 1°.
==Types of cameras==
==Types of cameras==
The best-selling camera of any type, fixed-focus cameras have been made to shoot celluloid roll film of differing sizes, the disk film of the late 1970's to 1980's, and instant film. The size of the cameras allowed them to easily slip into pockets when not in use, and the added convenience of digital format beginning in the late 1990's allowed the user to upload finished images to a computer, dispensing with the development process of celluloid film.
The best-selling camera of any type, fixed-focus cameras have been made to shoot celluloid roll film of differing sizes, the disk film of the late 1970's to 1980's, and instant film. The size of the cameras allowed them to easily slip into pockets when not in use, and the added convenience of digital format beginning in the late 1990's allowed the user to upload finished images to a computer, dispensing with the development process of celluloid film.
Fixed-focus cameras have seen a sales decline from 52 to 44 percent in recent years,<ref>http://gigaom.com/2011/12/22/smartphones-killing-point-and-shoots-now-take-almost-13-of-photos/</ref> ironically from another, more convenient device with a point-and-shoot camera built in: the cell phone. Like the fixed-focus camera, the cell phone camera can be aimed at the subject and a picture taken at the touch of a button; however, the screen of the cell phone is the viewfinder, allowing the user to hold the phone comfortably away from him while aligning the phone for a good image. And since it is a cell phone, the image (or video, as cell phones have that capability) can be immediately sent to anyone worldwide, and advantage that fixed-focus cameras lack.
Fixed-focus cameras have seen a sales decline from 52 to 44 percent in recent years,<ref>http://gigaom.com/2011/12/22/smartphones-killing-point-and-shoots-now-take-almost-13-of-photos/</ref> ironically from another, more convenient device with a point-and-shoot camera built in: the cell phone. Like the fixed-focus camera, the cell phone camera can be aimed at the subject and a picture taken at the touch of a button; however, the screen of the cell phone is the viewfinder, allowing the user to hold the phone comfortably away from him while aligning the phone for a good image. And since it is a cell phone, the image (or video, as cell phones have that capability) can be immediately sent to anyone worldwide, an advantage that fixed-focus cameras lack.
== See also ==
== See also ==