How to adjust the aperture?

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. The aperture size is expressed by the value of f, the larger the value, the smaller the aperture, and the smaller the value, the larger the aperture. The smaller the f value of the aperture, the more light enters per unit time (because the aperture of the aperture is large), and the amount of light entering at the upper level is exactly twice that of the lower level. For example, if the aperture is adjusted from f8 to f5.6, the amount of light entering will double. We also say that the aperture is enlarged by one level.

Apertures are like faucets. If you turn it up, a lot of light will enter; If you turn it down, you will only get less light. From the upper left to the lower right of the figure, the aperture size is in different states of closed aperture, f 1 1, f8 and f4 respectively. From this, we can also understand that the larger the aperture, the stronger the light projected on the CCD photoreceptor of the digital camera. When we buy lenses, the size of the aperture is a very important factor, which directly affects the price. A large aperture lens is much more expensive than a small aperture lens. Large aperture can perform better in dark environment, get more light without changing the shutter speed, and let the photos be exposed normally. At present, the aperture of professional zoom lenses can generally be opened to F2.8, and fixed-focus lenses such as Canon 50MM can be opened to 1.4! Large aperture can not only get more light, but also get the effect of shallow depth of field (the so-called depth of field means that when the focal length is aimed at a certain point, the front and back can still be clear). The larger the aperture, the shallower the depth of field, which is vulgar, that is, the subject is clear, the background is blurred, and the theme is highlighted. It is often used for portrait shooting. The smaller the aperture, the greater the depth of field, that is, the foreground background is clear and suitable for taking landscape photos. Controlling the depth of field is not only related to the aperture size, but also related to the focal length and shooting distance of the lens. Today, I mainly talk about different combinations of aperture, shutter and ISO to take photos with different effects.