Search results
Results from the WOW.Com Content Network
The lens aperture is usually specified as an f-number, the ratio of focal length to effective aperture diameter (the diameter of the entrance pupil). A lens typically has a set of marked "f-stops" that the f-number can be set to. A lower f-number denotes a greater aperture which allows more light to reach the film or image sensor.
A Canon 7 mounted with a 50 mm lens capable of f /0.95 A 35 mm lens set to f /11, as indicated by the white dot above the f-stop scale on the aperture ring. This lens has an aperture range of f /2 to f /22. The word stop is sometimes confusing due to its multiple meanings. A stop can be a physical object: an opaque part of an optical system ...
A Nikon-style mode dial showing aperture priority mode.. Aperture priority, often abbreviated A or Av (for aperture value) on a camera mode dial, is a mode on some cameras that allows the user to set a specific aperture value while the camera selects a shutter speed to match it that will result in proper exposure based on the lighting conditions as measured by the camera's light meter.
Many PC and TS lenses incorporated a feature known as a "preset" aperture, which lets the photographer set the lens to working aperture, and then quickly switch between working aperture and full aperture without looking at the aperture control. Though slightly easier than stopped-down metering, operation is less convenient than automatic operation.
The two lenses are typically linked to ensure that they remain focused at the same distance. TTL: Through the lens. Through the lens metering measures the luminance after it has passed through the camera lens, thus providing readings or settings that allow for aperture and focus changes, filters, etc. [11] UV: Ultraviolet. The electromagnetic ...
Photographers can use the lens scales to work backwards from the desired depth of field to find the necessary focus distance and aperture. [38] For the 35 mm lens shown, if it were desired for the DOF to extend from 1 m to 2 m, focus would be set so that index mark was centered between the marks for those distances, and the aperture would be ...
Aperture settings are usually not continuously variable; instead, the diaphragm has typically 5–10 discrete settings. The normal "full-stop" f-number scale for modern lenses is as follows: 1, 1.4, 2, 2.8, 4, 5.6, 8, 11, 16, 22, 32, but many lenses also allow setting it to half-stop or third-stop increments.
Lens speed is the maximum aperture diameter, or minimum f-number, of a photographic lens. A lens with a larger than average maximum aperture (that is, a smaller minimum f-number) is called a "fast lens" because it can achieve the same exposure as an average lens with a faster shutter speed. Conversely, a smaller maximum aperture (larger minimum ...