You probably mean the lens will not focus to infinity on the groundglass. And probably it had proper infinity focus on the film. SO it's better that you could not adjust the lens distance. Now, the groundglass mis-focus can have two causes: (a) the groundglass position; (b) the reflex mirror position. Better make sure you adjust the one that is mis-aligned; although in principle you can compensate one with the other, except for side effects on frame alignment.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.
From my experience, the best (most accurate) method has been described by Rick Oleson:
- Open the back of the camera to let some light in
- place a known good reflex camera (preferably with a split-prism at the center of the ground glass) close in front, staring into the lens of the camera under test.
- With both cameras focused at infinity, the ground glass of the camera under test should apear to be in focus. This checks for infinity focus on the ground glass.
- Similar method can be used to check proper infinity focus in the film plane; just place a plane object (a piece of ground glass, or a piece of "magic" adhesive tape) precisely in the film plane (reference: film guides), open the shutter of the camera under test (B setting, cable release lock), and check whether you see in the known good camera the film plane (of the camera under test) to be in focus.