I think I found a bug.
If I set up my camera with a camera shift of .3 and go to the preview render view, the view does not look the same as blender 3d viewport. If I want the preview render to look the same, I have to double the value to .6. However, when the final render is done, this looks correctly the same as the 3d view in blender viewport.
Any queries, please reply.
Regards,
Rob.