Hello arafat,
Regularized model is suitable for the case when the drone flies without turning the camera, i.e. during the shooting to a new route, the camera does not turn and the drone moves in parallel.
When using a Regularized, only two parameters are optimized for each frame: axis shift XY in the plane of the photo. When using the Full model, 6 parameters are optimized for each frame: shift along the XYZ axes and rotation along the XYZ axes.