What does exposure compensation mean?

Exposure compensation is also a method of exposure control. It is generally around ±2-3EV. If the ambient light source is dark, the exposure value can be increased (for example, adjusted to +1EV, +2EV) to highlight the image. Clarity.

During the shooting process of a digital camera, if you press the shutter halfway, a picture similar to the final rendering will be displayed on the LCD screen, and the focus and exposure will start. The exposure at this time is exactly the exposure of the final image. If the picture is obviously brighter or darker, it means that the accuracy of the camera's automatic metering is greatly deviated, and exposure compensation must be forced. However, sometimes, the brightness displayed during shooting is different from the actual shooting result. Digital cameras can browse the picture immediately after shooting. At this time, you can more accurately see the brightness and darkness of the picture taken, and there will be no more discrepancies. If the shooting result is obviously brighter or darker, you need to reshoot and force exposure compensation.

When the shooting environment is dark and the brightness needs to be increased, but the flash cannot work, the exposure can be compensated and the exposure appropriately increased. When performing exposure compensation, if the photo is too dark, increase the EV value. Each increase of 1.0 in the EV value is equivalent to doubling the amount of light taken in. If the photo is too bright, reduce the EV value. Each decrease in the EV value by 1.0 , which is equivalent to doubling the amount of light taken in. The compensation interval can be adjusted in units of 1/2 (0.5) or 1/3 (0.3) according to different cameras.

When the white object being photographed looks gray or not white enough in the photo, you need to increase the exposure. Simply put, "the whiter, the more". This seems to be in line with the basic principles and habits of exposure. It's the opposite, but it's not. This is because the camera's metering often focuses on the subject in the center. The white subject will make the camera mistakenly think that the environment is very bright, so it will be underexposed. This is also a common mistake that most beginners make.

Since the shutter time or aperture size of the camera is limited, it is not always possible to reach the 2EV adjustment range. Therefore, exposure compensation is not omnipotent. In an environment that is too dark, it may still be underexposed. This You should consider using a flash or increasing the ISO sensitivity of the camera to increase the brightness of the picture.

The exposure compensation range of almost all digital cameras is the same. It can be added or subtracted within plus or minus 2EV. However, the addition and subtraction are not continuous, but are based on 1/2EV or 1/3EV. Interval jump type. Early old-fashioned digital cameras such as Kodak's DC215 are based on 1/2EV intervals, so there are 8 levels -2.0, -1.5, -1, -0.5 and +0.5, +1, +1.5, +2***. The current mainstream digital cameras are divided into more detailed grades, with intervals of 1/3EV, so there are -2.0, -1.7, -1.3, -1.0, -0.7, -0.3 and +0.3, +0.7, + There are 12 levels of compensation values ??such as 1.0, +1.3, +1.7, +2.0, etc.

Generally speaking, the smaller the brightness contrast of the scene, the more accurate the exposure, and vice versa, the deviation will increase. There are high and low grades of cameras. If the camera is of a higher grade, the metering will be more accurate. If the camera is of a lower grade, the metering will be more accurate. If it is a traditional camera, the latitude of the film is relatively large, and exposure deviation will not be a big problem within a certain range. However, the CCD latitude of a digital camera is relatively small, and slight exposure deviation may affect the overall effect.

In short, the adjustment of exposure compensation is determined by experience and sensitivity to color. Users must compare the picture quality, clarity, restoration and noise size under different exposure compensations in order to Take the best pictures possible.

Films with rich gradations can generally be said to be correctly exposed. Most modern cameras have internal light metering functions. In most cases, shooting according to the data provided by the light meter can make most films obtain the correct exposure. Basically correct exposure, this is because the light meter reads 18% gray tone, and 18% gray is the average light value in our daily life scenes, such as our skin color. However, correct exposure does not mean the best exposure. Especially when white or bright objects dominate the picture, simply shooting according to the camera's metering data will cause obvious deviations, that is to say, the white objects in the photo will , bright objects, and dark objects all show 18% gray. Such photos are naturally unsatisfactory. Therefore, in the absence of an incident light meter or gray board, exposure compensation plays an extremely important role. Our common cameras with automatic exposure function generally have exposure compensation function, while manual exposure cameras need to compensate for exposure through shutter and aperture control.