Results for “Aperture”
64 terms · page 1 of 3
Aperture
The adjustable opening inside a lens that controls how much light passes through to the sensor, and with it the depth of field.
Optics, Lenses & FiltersAperture Blades
The overlapping leaves inside a lens that form the iris, whose number and shape determine the geometry of the opening.
Exposure & MeteringAperture Priority
A semi-automatic mode, marked A or Av, in which the photographer sets aperture and ISO while the camera chooses shutter speed.
Exposure & MeteringEffective Aperture
The working f-number of a lens once it is focused close, which is always darker than the marked aperture because the lens is extended away…
Film, Darkroom & Historic ProcessesCamera Obscura
A darkened room or box in which a small aperture projects an inverted image of the outside world onto an inner surface.
Cameras, Formats & SystemsDepth of Field Preview
A control that stops the lens down to the working aperture so the actual depth of field can be seen before exposure.
Focus & Depth of FieldDepth of Field Scale
Markings on a lens barrel showing the near and far limits of sharpness for each aperture at the set focus distance.
Optics, Lenses & FiltersDiffraction
The spreading of light waves as they pass the edge of an aperture, which softens the image at small f-numbers.
Optics, Lenses & FiltersDiffraction Limit
The aperture beyond which diffraction, rather than lens design or sensor resolution, becomes the factor limiting sharpness.
Optics, Lenses & FiltersEntrance Pupil
The apparent size and position of the aperture as seen from in front of the lens, which is what the f-number is calculated from.
Exposure & MeteringEquivalent Exposure
Any different combination of aperture, shutter speed and ISO that yields identical image brightness.
Optics, Lenses & FiltersExit Pupil
The apparent size and position of the aperture as seen from behind the lens, which governs how light strikes the sensor.
Exposure & MeteringExposure
The total amount of light that reaches the sensor or film, set by the combination of aperture, shutter speed and the scene's brightness.
Exposure & MeteringExposure Triangle
The teaching model that links aperture, shutter speed and ISO as three interdependent controls, where changing one requires compensating…
Exposure & MeteringExposure Value (EV)
A single number describing every combination of aperture and shutter speed that produces the same exposure.
Exposure & MeteringF-number
The ratio of a lens's focal length to the diameter of its entrance pupil, written f/2.8, f/8 and so on, and the standard way of stating…
Lighting & FlashGuide Number
A measure of a flash's power, equal to the product of the correct aperture and the subject distance at a stated ISO.
Focus & Depth of FieldLow-light AF Rating
The dimmest light level at which a camera's autofocus is specified to work, quoted in EV at a stated aperture and ISO.
Exposure & MeteringManual Mode
A mode, marked M, in which the photographer sets aperture and shutter speed directly and the camera only advises.
Cameras, Formats & SystemsPinhole Camera
A lensless camera that forms an image through a tiny aperture, giving infinite depth of field and extremely long exposures.
Exposure & MeteringProgram Mode
An automatic mode, marked P, in which the camera selects both aperture and shutter speed while leaving other controls to the photographer.
Sensors & Digital CaptureSensor Dust
Particles settling on the sensor's cover glass, which appear as dark spots in the image at small apertures.
Exposure & MeteringShutter Priority
A semi-automatic mode, marked S or Tv, in which the photographer sets shutter speed and ISO while the camera chooses aperture.
Exposure & MeteringT-stop
A measured aperture value that accounts for the light a lens actually transmits, rather than the geometric ratio an f-number implies.