Focusing problem, Nikkormat FTN

[GeorgeX]

Nikkormat FTN, otherwise perfect, doesn't focus correctly with f shorter than 50 mm. With increasing f it gets better. I assume there is a misalignement along the way through the screen and prisma. Does anyone have more specific suggestions? How to allocate/repair the problem? Thanks/George

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[Sito]

What lens are you using? Does this problem occur with all lenses?

 

[GeorgeX]

Have tried with f=24/2,8, 85/1,8 and 35-135 zoom.

 

[volkerm]

To check mirror alignment: is the viewfinder focus plane tilted?
Does the focus agree between viewfinder and film level?
Perhaps the focusing screen was removed and later inserted upside down?

 

[Sig]

I tend to agree with Tante Erna, the most likely cause would be the mirror to be misaligned. The focusing screen is not interchangeable on this model so this will probably not be the reason. Just checked on my Nikkormat: the mirror sits in a metal tray, suspended by two arms left and right. Maybe it is not pushed right home or something is bent.

Very sturdy camera otherwise, nothing much is likely to fail, apart from the ring resistor in the meter.

regards
Sig

 

[GeorgeX]

Dear All,

thanks for your advice. I started focusing on the mirror. It rests on a spring-loaded arm, which can be adjusted with an excenter screw. What you need is a 90-degree bent screwdriver to get at it. I made one (killing another). At the second trial I got rather good agreement with my FM2, both through the 24/2.8-lens and the 35-135 manual zoom. It remains to see whether the mirror will pick the arm away from the correct position. Time to load the camera for a real test!