Good question Ted. Set everything up on the tripod. Made the first image with the lens rotated about 3 degrees counter-clockwise, loosened the tripod collar, rotated it about 1/12 degrees clock-wise, then level and then two more going 1 1/2 degrees clockwise. As always with blurs, I took a lot. And as often happens, the first one was the winner. Don’t ask me how I got the point of rotation offset….