Malcolm_J
Member
I have discovered a problem with my beautiful Zenit 3m. The focusing is not quite correctly set. If I focus on a distant object, the lens ring tells me it is 10m away. If I set the lens to infinite, then the TTL view is out of focus.
I know that the lens is correct relative to the film, because if I set the lens at infinite and take a picture, the focus is perfect. But if I have to use the focusing for something closer to, then I won't get a clear picture, because the mirror and the focusing screen are not quite correctly adjusted.
Now I know that with the Zenit E, there is a mirror adjustment screw that makes this problem a 5 minute job to fix. However, I cannot see any such adjuster in my 3M. Do I have to reshim the focusing screen? Or is there a simpler way of doing this?
Advice gratefully accepted!
I know that the lens is correct relative to the film, because if I set the lens at infinite and take a picture, the focus is perfect. But if I have to use the focusing for something closer to, then I won't get a clear picture, because the mirror and the focusing screen are not quite correctly adjusted.
Now I know that with the Zenit E, there is a mirror adjustment screw that makes this problem a 5 minute job to fix. However, I cannot see any such adjuster in my 3M. Do I have to reshim the focusing screen? Or is there a simpler way of doing this?
Advice gratefully accepted!
ZorkiKat
ЗоркийК&
Malcolm_J said:
Malcolm J,
You've definitely a mirror problem. Adjusting the mirror in a Zenit 3m is different from what is done with the M42 Zenit. To do this, you'd need to take the top plate off. There are two tall screws found in front of the prism. I forget now which does what, but one of the screws would lower the mirror and the other, raise it. Both screws need to be loosened first before any adjustment is done.
Jay
Malcolm_J
Member
Thank you for replying, ZorkiKat. I was afraid it might involve some work under the bonnet. So I shall get myself some jeweller's tools and roll my sleeves up and get stuck in.
This might be a good time to replace the focusing screen with a later one. Does anyone know a reliable supplier? I have read that the screen for the later Z-122 was better and fitted the 3M.
All in all, I can't see it being a fraction so bad as stripping down a Suzuki GT750 motorcycle engine to replace the crankshaft oil seals.
This might be a good time to replace the focusing screen with a later one. Does anyone know a reliable supplier? I have read that the screen for the later Z-122 was better and fitted the 3M.
All in all, I can't see it being a fraction so bad as stripping down a Suzuki GT750 motorcycle engine to replace the crankshaft oil seals.
Malcolm_J
Member
A little further investigation reveals that the actual adjustment required is (literally) the thickness of a piece of paper. Bearing in mind how crude the mechanism is, I am not surprised it is out of adjustment by that amount. There is no way I am pulling the top off just for that. I am going to either glue a shim to the catch that the mirror rests on when the camera is cocked, else do some judicious bending of the notched arm that holds the mirror down. I will hold off until the weekend when I will be able to get out in daylight and see things at infinite.
ZorkiKat
ЗоркийК&
Malcolm_J said:
Malcolm,
How would you determine how much paper to put for the necessary spacing?
Bending would not be a great idea either since it may introduce new issues in the mechanism. I believe that taking the top off is still the wiser move. Many 3M have been found with the same problem as yours has. It appears that mirror /screen displacement is inevitable, as a consequence of movement of the parts as they function.
BTW, I have mistakenly attributed the error to the mirror. With 3M, the part which is adjustable is the screen.
Jay