What is an aperture?

Aperture is a photographic term.

Aperture is the lens of a camera, which is composed of several extremely thin pieces of metal, through which light can pass. The amount of light entering the lens is controlled by changing the size of the hole. The larger the aperture, the more light enters through the lens. The value of aperture is usually expressed by f/1 and f/2. The larger the number, the smaller the aperture, and vice versa. When the shutter speed is constant, the appropriate aperture size can bring normal exposure.

if the aperture is too large, it will lead to overexposure, and if it is too small, it will lead to underexposure. Aperture is not only used to adjust the exposure, but also to control the depth of field of the picture. The relationship between depth of field and aperture is that the larger the aperture, the shallower the depth of field, and the smaller the aperture, the deeper the depth of field. The smaller the aperture, the larger the corresponding value of f. For example, the aperture of f/22 is smaller than that of f/16.

the function of aperture

generally speaking, the exposure of a camera at the same sensitivity is determined by the aperture size (aperture f value) and shutter speed. In the previous article, we know that the F value of the aperture = the focal length of the lens/the diameter of the lens aperture, that is to say, the smaller the F value of the aperture, the larger the aperture, and the greater the light input. So we can increase the aperture to increase the shutter speed, or decrease the aperture to decrease the shutter speed.

large aperture lenses usually perform well in poor light. A series of lenses known as "night mirrors" in the field of SLR cameras, such as Nikon's Noct 58mm/F1.2 and Leica's NOCTILUX-M5mm/F.95aph night lenses, all have large apertures. Aperture can not only change the shutter speed, but also change the depth of field.