Hi jayavant, thank you very much for your reply. I also suspect it is from the film plane. The distance from the film plane and the front of the lens is about 5cm, or 2 inches. At f2.8 and 0.9m, this 5cm is huge.
I tested three of my rollei 35& 35s at 1m and 1.5m, with the film plane as the start point for the distance, and they all turn out to be near focusing in a silimar way. Therefore I am wondering if it is actually from the film plane.
Originally Posted by jayavant
I suspect it would be from the film plain.
But how accurate do you have to be?