The camera or camera obscura is the image-forming device, and photographic film or a silicon electronic image sensor is the sensing medium. The respective recording medium can be the film itself, or a digital electronic or magnetic memory.
Photographers control the camera and lens to “expose” the light recording material (such as film) to the required amount of light to form a “latent image” (on film) or “raw file” (in digital cameras) which, after appropriate processing, is converted to a usable image. Digital cameras use an electronic image sensor based on light-sensitive electronics such as charge-coupled device (CCD) or complementary metal-oxide-semiconductor (CMOS) technology. The resulting digital image is stored electronically, but can be reproduced on paper or film.
The movie camera is a type of photographic camera which takes a rapid sequence of photographs on strips of film. In contrast to a still camera, which captures a single snapshot at a time, the movie camera takes a series of images, each called a “frame”. This is accomplished through an intermittent mechanism. The frames are later played back in a movie projector at a specific speed, called the “frame rate” (number of frames per second). While viewing, a person’s eyes and brain merge the separate pictures together to create the illusion of motion.
In all but certain specialized cameras, the process of obtaining a usable exposure must involve the use, manually or automatically, of a few controls to ensure the photograph is clear, sharp and well illuminated.
Many other elements of the imaging device itself may have a pronounced effect on the quality and/or aesthetic effect of a given photograph; among them are:
* Focal length and type of lens (telephoto or “long” lens, macro, wide angle, fisheye, or zoom)
* Filters placed between the subject and the light recording material, either in front of or behind the lens
* Inherent sensitivity of the medium to light intensity and color/wavelengths.
* The nature of the light recording material, for example its resolution as measured in pixels or grains of silver halide.