ve factors that affect exposure are: the combination of aperture value and shutter value and sensitivity. The size of the exposure is determined by the product of the amount of light irradiated on the imaging carrier and the exposure time. EV (Exposure Value) represents the exposure value, which is determined by the brightness of the scene and the set sensitivity, and represents the combined value of the aperture and shutter based on the set sensitivity.
Note that exposure and EV value are two different concepts. Exposure is related to level of detail, and level of detail is related to image success or failure.
- How to achieve exposure control? The so-called exposure control is the process of controlling the amount of exposure by adjusting the light source illuminance, the brightness of the scene, the sensitivity of the film or photoreceptor, the shutter time of the camera, the size of the aperture, etc. The first purpose of exposure control is to match the exposure combination with the brightness of the scene to perform correct exposure, thereby reproducing the original appearance of the scene. The key to exposure control is to match the dynamic range of sensitivity, the light ratio of the film and the light ratio of the subject. Specifically, when the brightness of the scene is high, use a small aperture and high speed to reduce the exposure; when the brightness of the scene is low, use a large aperture and low speed to increase the exposure. The correct exposure can also be achieved by controlling the camera sensitivity and the light ratio of the shooting environment. For example, when shooting people, the light reflected by the reflector can be used to increase the exposure on the people’s face.
- In theory, there is only one most accurate exposure under the same light conditions. But from the perspective of artistic personality, under the same light conditions, there are as many suitable exposures as there are photographers.