What is the aperture in photography?

Aperture is a device used to control the amount of light entering the photosensitive surface of the fuselage through the lens, usually in the lens. For the manufactured lens, the diameter of the lens cannot be changed at will, but the luminous flux of the lens can be controlled by adding a polygon or circular aperture grating with variable area inside the lens. This device is called an aperture.

2. Calculation method

The aperture size is expressed by f value.

Aperture f value = lens focal length/lens aperture diameter

As can be seen from the above formula, to achieve the same aperture f value, the aperture of a long focal length lens is larger than that of a short focal length lens.

3. Aperture function

(1) 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. That is to say, the smaller the F value (other parameters remain unchanged), the more favorable it is for shooting at night. 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, with large aperture (small aperture value), small depth of field, small aperture (large aperture value) and large depth of field!