What does F mean in SLR cameras?

F in SLR cameras stands for aperture size.

Aperture is a device used to control the amount of light entering the photosensitive surface of the fuselage through the lens. Usually in the camera. In order to express the pore size, we use the value of F/.

For the manufactured lens, we can't change the diameter of the lens at will, but we can control the luminous flux of the lens by adding a polygon or circular aperture grating with variable area inside the lens. This device is called an aperture.

Its size determines how much light enters the photosensitive element through the lens. We use f value to represent the aperture size, where F= lens focal length/lens effective aperture diameter. Aperture f value = lens focal length/lens aperture diameter. The larger the f value, the smaller the aperture. Conversely, the smaller the f value, the larger the aperture.

Extended data

The function of aperture

1. It can adjust the amount of light entering the lens. When taking pictures, if the light is strong, you should narrow the aperture, if the light is dark, you should open the aperture. In other words, the smaller the f value, the more favorable it is for night shooting. The adjusting ring on the rotating lens or the knob on the digital camera body is used to adjust the aperture size.

2. Aperture is the most important factor to determine the depth of field. Small aperture (large aperture value), depth of field, large aperture (small aperture value), depth of field! For example, nearsighted friends, if they don't wear glasses, always habitually squint at things, so they can often see things clearly. To use photographic terminology, this is called: narrowing the aperture (pupil) and increasing the depth of field!

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