Shimming lens on Zorki 4
I have a Zorki-4 that I am certain needs to have the lens shim adjusted. I did the procedure described by D_V_D_27 in the repair notes section... I aligned the RF adjustment to the markings on the lens to the actual distance measurements. So, through the rangefinder, and object at infinity aligns at infinity, 1 meter at 1 meter, 2 meters at 2 meters, etc.
But close up pictures (closer than 4-5 meters) are still out of focus with the lens at f8 or wider (and I have tried the same experiment with 3 other 50mm lenses... same result). So I put one of my Olympus focusing screens into the film gate and, voila, objects that are 1.5 meters away (actually measured) focus on the ground glass with the lens distance scale set to 4 meters.
So here is my logic. When the lens is set for 4 meters, it is closer to the film plane than when it is set to 1.5 meters. This means that I need to move the lens closer to the body, which means I need to remove some of the paper lens shims, right?
There are 2 paper lens shims in this Zorki-4 (in fact, there are 2 shims in all 3 Zorki-4s I have opened up...). It is hard to believe that removing 1 or both of these will make a difference... so is there some guideline about the shims? 1 shim = X% of a rotation of the focus helix or something like that? Or is there some other adjustment of the lens-to-body distance that I haven't found?
If anyone has any operational or experiential insight here, please provide some guidance. I'd like to not have to discover it all through Trial & Error, but I can.
Thanks, in advance...