There are dark blue shadows in the corners of the video recorded by Sony 1500c. Please help me solve the problem.

This phenomenon is called vignetting in photography. There are many ways in which this happens. For example, the mismatch between the lens and the body causes vignetting, or the lens cover blocks it, causing vignetting. Vignetting, or there is a problem with your lens itself. Another possibility that is more troublesome is that the sensor element of your photography camera has vignetting. However, if you shoot when the light is better, you will not notice it at all. However, when the light is better, you will not notice it at all. When it's darker, I hate how it will appear tomorrow.