Problems in camera intrinsic parameters setting

[Karltommy]

I've met some problem with the camera intrinsic parameters setting in webots. When I set the focalDistance and focalLength with some value, the image became indistinct. I would like to know if there are some rules in webots to set the camera intrinsic parameters, which can ensure the images transferred from the camera sensor valid for postprocessing. It is obvious in the picture that the upper image is indistinct comparing with the lower one. The camera for the upper image were set in parameters as follows: focalDistance =1200, focalLength = 1200, width = 1920, height = 1080, fiedofView = 1.57.