Basic knowledge of cameras
The main parameters of film refer to the sensitivity of film, which is denoted by ISO value (short for International Standards Organization). The higher the ISO value, the higher the sensitivity of film/sensor, the easier the exposure.
There is a group of overlapping metal blades in the camera lens. The aperture size and opening time of the overlapping metal blades determine the amount of exposure in a single phase, and also produce the aperture and speed of the camera.
When the exposure time is fixed, the larger the aperture, the greater the exposure of the film. Represented in f/values. The aperture values of general cameras are f/1.4, f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16, f/22. The exposure will be doubled or halved when the aperture values jump up or down one grid.
Of course, it mainly refers to shutter speed. As mentioned above, the opening time of metal blades is determined. Nowadays, the shutter speed of many cameras is controlled by the computer film of the camera itself. In traditional cameras or some semi-professional or higher-level cameras, the shutter speed of the camera still needs to be manual, mainly including the following, from slow and fast, 1, 1/2, 1/4, 1/8, 1/15, 1/30, 1/60, 1/125, 1/250, 1/500, 1/1000 seconds, and in some more professional cameras, there are longer or shorter shutter speed settings than these. Similarly, every time the shutter speed jumps up or down, the amount of exposure doubles or halves.