Still cameras {camera}| can expose film to light to record images.
lens
Cameras can move lens forward or backward {focus, camera}, to make picture clear. Close-ups use lens far forward. Cameras can have bellows or extension rings to allow lens to go far forward. Special lenses {zoom lens} can keep focus at different magnifications. Special lenses {telescopic lens} can magnify. Special lenses {fish-eye lens} can be wide field.
diaphragm
Cameras can make smaller or larger openings {diaphragm, camera} {iris diaphragm} {f-stop}, so picture is not too dark or light. Diaphragms usually have an iris of overlapping metal leaves. Diaphragms have positions 2 for wide open, 2.8, 4, 5.6, 8, 11, 16, 22, and 32 for almost closed. Larger numbers reduce area by half.
shutter
Cameras can open for periods {shutter, camera}. Shutters are fast, so motions are not blurs. Shutters open long enough to receive enough light. Shutter irises can be set near lens {between-the-lens shutter}, which have speeds from 1/2000 second to several seconds. Shutters used in small cameras can be rectangles, which pass across opening near film at fixed speed but which have adjustable size.
Camera shutter speeds are usually 1/25, 1/50, 1/100, and 1/200 second. Times of 1/50 second or faster prevent unsteady-hand blur.
accessories
Camera accessories include three-legged stand {tripod}, colored plastic disc {filter, camera}, and electronic flash {flashgun}.
Cameras {movie camera}| can have a shutter that repeatedly opens for 1/30 second. Cameras use holes in film sides {sprocket, film} to position new film frame behind lens, 16 or more times a second. Cameras hold film frames for 1/30 second. Cameras repeat the process. Film moves by gears pulling film at film sprockets. Take-up reel turns as main reel turns.
Mirrors reflect image onto ground glass screen {reflex camera}|.
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Date Modified: 2022.0225