The modern, film-based single lens reflex (SLR) camera is a complicated of electronics, mechanics, and ultra high-precision optics. A main element of its operation is concerned with winding-on and rewinding the film - in the camera illustrated right here, a motor performs this function as effectively as controlling the mirror action. As you would expect, autofocus cameras demand a further layer of difficult integration between the electronics, optics, and mechanics.
While a digital camera is no less difficult in its mechanical and optical building, its electronics are far additional powerful than you would come across in a film-based model. A major saving is not getting to transport the film -the style for a static photosensor is far less difficult than that for a moving strip of film. But almost all other film-based camera operations are required.
Image structure
Film
- silver grains or dye clouds of varying size distributed in a random pattern.
Digital
- exact same-sized sensor pixels arranged in a normal grid, or raster array.
Colour recording
Film
- colours in the scene separated by red-, green-, and blue-sensitive layers.
Digital
- colours in the scene separated by Bayer pattern of red, blue, and green filters.
Colour reproduction Image amplification
Film
- dye clouds of cyan, magenta, and yellow. Development by chemical action.
Digital
- interpolated from colour filter array. Electronic and digital processes.
Image good quality
Film
- depends on film speed, grain structure, and processing regime.
Digital
- depends on sensor resolution and interpolation techniques also compression, if applied.
Storage
Film
- image fixed by removing unexposed silver black and white stable, colour less so.
Digital
- image stored temporarily on memory cards or hard-disks.
