Beginners take pictures with M files, some are darker and some are brighter. It doesn't matter if you look at it alone, but it is obviously flashing when the video is formed.

There are two factors that may lead to the above problems.

1 Different shooting time or weather affects photos.

2 metering mode, general cameras include: evaluation metering, average metering, partial metering and spot metering. Depending on your focus, the camera will measure light in different places, and so will exposure value. However, if the appropriate exposure method is selected, this problem will not occur. It is suggested that you use average metering or evaluation metering (because you are a beginner, other metering modes are relatively difficult to master), so the above problems should not occur.

3 When shooting, the light source is different. For example, if you shoot in front of a light, you turn around and it becomes a backlight. So some photos are very dark and some are very bright.

4 Aperture, white balance and sensitivity are not fixed.

There is something wrong with the camera lens itself.