Great, Michal. I know your method is simple and easy to use but I'd rather not tie up both U1 and U2 for HDR. By using just one of the U positions I can leave it at a base exposure of 0EV so I can use it for standard bracketing purposes also. When I want to get 6 shots for HDR I will change the EV spacing from 1.0 to 2.0 and I'm ready to go. Both methods will work but consider the ways in which you may want to use your U positions with the amount of HDR you are shooting as this is certainly a user preference.