What is the EV value?

EV = exposure value, that is, exposure value, an expression of exposure. It expresses the reciprocal calculation method of aperture and shutter. For example: EV= 13, representing 1/30sec, f/16; 1/ 15，f/22； 1125, f/8 ... and a series of aperture/shutter combinations with the same exposure. The smaller the EV value, the greater the exposure. EV= 12, equivalent to 1/30, F/ 1 1, and so on. Generally speaking, the EV value can be calculated by combining the photometric value with the film sensitivity, the same EV and the same exposure, but different aperture/shutter combinations have different effects. A small aperture can get a large depth of field, and a large aperture can choose focus and theme. By changing EV, the subject can be placed in different brightness areas. Photometric EV range and exposure EV range are two different performance parameters of a camera, but many people don't know enough about their differences. Automatic metering camera, as well as metering EV value and exposure EV value. The range of photometric EV value is a parameter related to the performance of camera exposure meter, such as EV2- 16(F2.8, ISO 21100), which means that when the maximum aperture of exposure meter is 2.8, the film sensitivity is ISO 211. The EV value that can be exposed by the exposure meter on the camera refers to the range from the longest exposure time of the camera shutter with the largest aperture (except the B door) to the shutter with the shortest exposure time. For cameras with interchangeable lenses, because the maximum and minimum apertures of different lenses are uncertain, it mainly refers to the range of shutter time. Now shoot at home, don't think so much. The camera will automatically adjust, and the digital camera can see the shooting result immediately. Professional photography needs to master exposure value. For professional knowledge in this field, you can consult relevant materials.