I am now using the openCv function's to do the Camera calibration. But all the distortion coefficient parameters are incorrect especially the radius distortion. k2 and k3 often be the value greater than1 while the focal length and principal point seem correct. I cannot explain the reason and Does anyone know the reason and help me to solve this problem?
The parameters below is my intrinsic parameters in one experiment under the windows size is (640*480),using 8-by-8 chessboard, the square size is 2 centimeter and all the chessboard corners can be found correctly.
k1=0.0796868 , k2=1.64119 , k3= -38.8437, p1=-0.00536427 , p2=-0.00200758
principal point: 231.794 , 252.236
focal length: 1062.22, 1055.18