Guy Mancuso
Administrator, Instructor
Alpa's HPF rings is not that high resolved so I would guess that there is some small focus placement error that Arca RM3Di does slightly better. It would be interesting to test. On the other hand I think the Arca has entered overkill territory making the focus ring unnecessarily slow/cumbersome to work with. The Alpa/Cambo seems to have a nice tradeoff. I think it should be standard with HPF ring pre-mounted on all lenses though, I think being able to set exact focus distance in the blind is one of the key features of a pancake camera.
The Arca is very nice but I agree with you, first I'm not a math major and reading cheat sheets setting up offsets and all that stuff takes me away from being a shooter. Also Alpa/Cambo are the focusing style we done for years. Bob and Jack love playing with that stuff on the Arca. I find it boring and a PITA but it does work. I'm just not a fan of it. Rather shoot the Alpa, Cambo setups.