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stop number

stop number

1 8.4
A number that shows how wide a camera lens opens to let light in
  • noun
  • Specialized
: número f-stop
  • A lower stop number means a wider aperture and more exposure.

Examples

  • The photographer adjusted the stop number to control the amount of light entering the camera.

  • Many beginners confuse the stop number with shutter speed when learning about camera settings.

  • The stop number determines how much light enters the camera.

  • Many photographers consider the stop number essential for exposure.

  • A lower stop number means a wider aperture and more exposure.

  • The photographer adjusted the stop number to control the amount of light entering the camera.

  • Many beginners confuse the stop number with shutter speed when learning about camera settings.

Synonyms

speed
vsstop number
  • Specialized
1 8.5

How much light a camera lens lets in

names the same ratio but highlights aperture setting instead
f number
vsstop number
  • Specialized
1 7.5

A value that shows how wide a camera lens opens to let light in

is the same ratio specifically used to indicate aperture
focal ratio
vsstop number
  • Specialized
1 7.8

A number showing how bright an image is, found by dividing focal length by lens diameter

focuses on aperture indication rather than brightness or speed

Surface Forms

stop number singular
stop numbers plural

Morphology

stop + number

The photographic sense of 'stop number' (an optical ratio indicating aperture) is a specialized technical term whose meaning is not derivable from 'stop' as a device that prevents movement or 'number' as a count. A B1 learner who knows the constituent words would not predict this optical ratio from the literal meanings, so the expression is idiomatic/technical and therefore opaque.

Etymology

Stop number comes from the idea of a stop, a hole that controls light, and a number that measures how much light passes. A low stop number means a wide hole and more light, a high one means a small hole and less light, so photographers use it to show the lens 'aperture' and control how much light reaches the camera.