A very short post about solving (at least hoping to have solved it) a front focus problem I had with my newly bought 1987 (probably) Nikon FA (here shown side by side with an Olympus OM30):
There is a lot of nice attention to details in the construction of the Nikon FA. With age, however, some of the settings will change. I was unhappy to see that none of my lenses seemed to focus correctly to infinity (the lens barrel would show 6 m when the split prism viewfinder would indicate infinity focus). Thus, a front focusing problem. What to do ?
Since there was also a slight misalignment of the mirror angle itself (image in focus in the center but out of focus in the upper part of the focusing screen was one good diagnostics), I tried to move the only screw that looked like the ‘eccentric pin’ for mirror adjustment mentioned in the FA manual. Turning clockwise for maybe 15° seems to have solved the problem.
Both the focusing and the lack of parallelism with the film plane of the viewfinder are gone. I took me several hours to dig some information on this matter (without actually founding a lot) and 5 minutes to actually solve it by using a kitchen knife. There was a risk of damaging the camera, so don’t follow this advice if you don’t feel at ease with fine mechanics. It is important that you first diagnose the problem correctly. Good luck.