Aperture is a round partition, consisting of petals, which is located inside the lens. It adjusts the diameter of the hole in the lens through which light passes. It is also used in https://www.artlook.us/service/wedding-proposal-photography/.
The f-number is denoted by F/x, where the number x is the ratio of the AF to the hole diameter. For example, F / 5.6, F / 8, etc., the larger this number, the more the aperture is closed.
The aperture affects the exposure and the depth of field of the depicted space. The wider it is open, the more light enters the matrix. Aperture and shutter speed are related.
The wider the aperture, the slower the shutter speed required. The wider it is open, the shallower the depth of field. Covering the aperture makes the depth of field greater.
Aperture is set in priority mode or in full manual mode of the camera. On older lenses, it was adjusted with the aperture control ring on the lens itself.
To increase the exposure by 1 stop, you need to divide the aperture value by 1.4 and set it to the number that turned out. For example, we now have an aperture of F / 8. To increase the exposure by 1 stop, divide 8 by 1.4 and get 5.7.
We round up to the nearest number that can be set in the lens, in our case it is F / 5.6. Opening the aperture from F/8 to F/5.6 increases the exposure by 1 stop. To reduce the exposure by 1 stop, you need to multiply 8 by 1.4 to get F / 11.
In the characteristics of the lens indicate how much the maximum aperture can be opened in it. This is an important characteristic, the aperture ratio of the lens depends on it. There are fast lenses for which it opens up to F / 2.8-F / 1.2. These lenses tend to be expensive.
The price of a lens depends on its aperture ratio, or rather on how much the aperture can be opened in it.
On my Nikon 18-55 lens, different aperture ratios are different at different FRs, on FR 18 mm the aperture can be opened up to F / 3.5, on FR 55 mm you can open up to F / 5.6. And on my 50 mm fix, the aperture opens to F / 1.8.
It also affects the sharpness of the image, the maximum open sharpness at the edges of the frame is reduced. In order for the image to be as sharp as possible across the entire field of the frame, it must be covered by 2-3 stops, in different lenses in different ways. You can check it by experiment: take a picture of a brick wall at different apertures and see the results.