What does the f of the lens mean?

In the field of film and photography, f is often used to refer to the value of aperture. Aperture value is a parameter that controls the amount of light entering the lens. The bigger it is, the more light it enters, and vice versa. In a camera, the value of f is usually a regular sequence, such as 4, 2, 8, 4, 5.6, 8, etc. In fact, these values represent the size of the lens aperture. Therefore, when we say "what is the F value of the lens", we are actually asking the aperture size.

F not only refers to the aperture value, but also refers to other meaning. In film production, f is often used to refer to the focal length. The focal length is the distance from the lens to the focal point, such as 50mm, 100mm, etc. Different focal lengths can present different picture effects. When shooting a movie, the director and photographer will choose different focal lengths according to the needs of the plot to achieve better shooting results.

F also has certain significance in the field of audio. In music production, f is often used to refer to the numerical value of frequency. Frequency refers to the number of cycles contained in sound waves per second, usually in hertz (Hz). For example, the number of sound wave cycles of 100Hz is 100 per second, while the number of sound wave cycles of 1000Hz is 1000 per second. In music production, we can change the properties of sound, such as volume, loudness and timbre, by adjusting the value of frequency.