f2.8 means that the aperture size on the lens is 2.8; the size of the aperture will affect the amount of light and depth of field. The smaller the aperture F value, the larger the aperture; under the same ISO and shutter conditions, the aperture The larger the screen, the brighter it will be.
#The operating environment of this article: Windows 7 system, Dell G3 computer.
What does f2.8 mean?
The F2.8 on the lens means that the aperture size of the lens is 2.8.
Aperture F value = lens focal length/lens effective aperture diameter. To achieve the same aperture F-number, a long focal length lens has a larger diameter than a short focal length lens.
The size of the aperture will affect the amount of light entering and the depth of field. The smaller the aperture F value, the larger the aperture. Under the same ISO and shutter conditions, the larger the aperture, the brighter the picture will be. The relationship between aperture and depth of field: The large aperture of F2.8 is easy to create a shallow depth of field with a blurred background; using the small aperture of F16, the subject and background will be clearer.
The complete aperture value series is as follows: f/1.0, f/1.4, f/2.0, f/2.8, f/4.0, f/5.6, f/8.0, f/11, f/16, f /22, f/32, f/44, f/6.
Extended information
The smaller the aperture F value, the larger the clear aperture, and the more light will enter in the same unit of time, and the previous The amount of light entering one level is exactly twice that of the next level. For example, if the aperture is adjusted from F8 to F5.6, the amount of light entering will double, and the aperture will be opened one step wider. The amount of light transmitted by F5.6 is twice that of F8. In the same way, F2 is 16 times the luminous flux of F8. When adjusting from F8 to F2, the aperture is opened four steps wider.
The function of aperture is to determine the amount of light entering the lens. The smaller the number after F, the larger the aperture and the more light entering; conversely, the smaller the number. When the shutter speed (exposure speed) remains unchanged, the smaller the aperture F value, the larger the aperture will be, the more light will enter, and the picture will be brighter; the larger the aperture F value, the smaller the aperture will be, and the picture will be darker.
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