Vivitar 220/SL focus adjustment
I just grew my old 35mm collection with a Vivitar 220/SL. The camera needs the typical cleaning and going through but was otherwise in excellent condition. I did notice fairly quickly that it would not focus to infinity. As I looked at how this camera is made, the lens mount to film plane is not adjustable. As I was cleaning old foam from the top of the focus screen I noticed ( took a while ) that the focus screen distance is adjustable ( as well as tilt ). It looked like someone did some work before and just tightened the screws that set the screen distance. No big deal, I would have probably done the same thing not knowing this design. Now the issue is getting it set right. I have another 220/SL body I bought for parts, but the focusing seems to be OK ( not previously messed with... I think ). My thought is to use the parts body on a bench and focus on a piece of graph paper fairly close in ( near minimum focus distance ) with the lens wide open. Then focus as critically as I can. Mount the same lens on the good body, set it in the same place with the lens set at the previous focus and use the screen adjustment screws to bring the image into focus. The graph paper should help me make sure the screen is also square with the focal plane. I'm sure I can come up with a way to make sure the bodies are set exactly in the same spot.
Might also tweak the meter to use a 1.55V silver battery while I'm in there. There are some pots, need to try and find a service manual so I can see what the circuit is. Alternately, I can do the diode drop mod which seems to work very well on my OM-1s
Any thoughts on a better way?