Exposure compensation of SLR camera

1, yes, only useful in files A, S and P.

2. There is no exposure compensation under M file. You can manually control the aperture and shutter to adjust the exposure. It's not that most cameras can't set exposure compensation under M file, but all cameras can't set exposure compensation under M file.

3. Exposure compensation is actually to adjust the aperture or shutter. And you have set the aperture and shutter manually in manual mode.

So it will not modify the parameters you set.

4. There is no exposure compensation problem in M file.

5. The camera comes with a reflective exposure meter, which determines what combination of aperture and shutter should be used according to the amount of light reflected by the subject to the lens (most cameras now use TTL to measure the light passing through the lens).

But the amount of light reflected into the camera will be affected by the color. For example, in the same environment, white objects will reflect a lot of light. If you measure light on a white object, the camera will think that the ambient light is too bright (which is not the case) and reduce the exposure. The result is that the photos taken are "underexposed". On the other hand, the result of photometry for black objects will be "overexposure".

Therefore, in this environment, it is necessary to adjust the exposure compensation, measure the light of white objects and increase the exposure compensation. Adjust the exposure compensation to+1EV, that is, tell the camera to adjust the aperture or shutter to increase the light input by 1 times to ensure that there will be no underexposure. In the same way, measure light for black objects and reduce exposure compensation.

So is there a color that can truly reflect the amount of ambient light? Yes, it is 18% neutral ash. Therefore, many professional photographers will carry a "grey card" with them and obtain accurate exposure parameters by measuring the light of the grey card. In fact, all exposure meters (including the camera's own exposure meter or hand-held exposure meter) are based on the reflected light of 18% gray scale.

Therefore, the exposure meter is not accurate in all cases. Whether you measure white light or black light, the exposure meter thinks that "this is the reflected light of 18% gray". Therefore, exposure compensation is actually used to make up for the inaccurate function of exposure meter.

6. Pure manual film machine has no exposure compensation.

Supplementary question:

In the film age, photographers can use exposure meters to measure light. If there is no exposure meter in the camera, the photographer will use a hand-held exposure meter to measure light. If there is no exposure meter at hand, you can only adjust the exposure parameters of the camera by the photographer's experience.

The photographer adjusts the combination of aperture and shutter according to the principle of adding white and reducing black, adding more and reducing more. Usually, for all-white scenes, you need to increase the exposure by about 2.5 levels. If the exposure accuracy is very strict, use a gray card to measure light.

If the shutter speed doubles, the exposure will also double. Adding an aperture will also double the exposure. When the aperture and shutter are increased at the same time, the exposure is increased by 2 times.