OT: Zenit SLR focus defective

[PeterL]

Hi,

I'm sorry to post this off-topic question, but I wouldn't know where else to ask.

My girlfriend's Zenit (TTL, made in Russia, KMZ logo, ser.no., no extra markings) has given her all out-of-focus pictures. I took a look at it and foud that the focussing matte screen isn't straight in its place. Would it be possible for somebody with very little experience with fine mechanics to fix this ? The problem is that it needs to be pushed down from the top, which I of course cannot reach from the mirror box. Any good repair guides that tell me how to take off the top ?


Peter.

 

[Jocko]

I think you'll probably find all you need here, Peter - http://www.xs4all.nl/~tomtiger

I sincerely wish you luck; Being hopelessly incompetant I murdered my Zenit whilst attempting repairs!

For real expert advice, visit the Zenit Camera Group - The above site has a direct link!

All the best, Ian

 

[ZorkiKat]

Peter,

You need not go farther than the mirror box of the Zenit TTL to adjust its focus. The screen is usually hard to displace. The root of the problem is likely elsewhere.

Before you even try to work on the mirror, check if the lens mount is correctly positioned- you can do this by placing a groundglass on the film rails, setting the shutter to B, setting the lens to infinity (at full aperture) and focusing on a very distant object. If the groundglass shows an infinity object correctly focused, you can conclude that both lens and camera mount are in order.

With this established, you can now assume that the camera's reflex mirror is off. Lift the mirror up (GENTLY!) and you'll find a rather thin, tall screw behind it. It should be found at the right side. This screw is the mirror position adjuster.

You might find that the screw is 'fixed' with lacquer. If you see plenty of this, you'd need to take some of it off with a cotton wad filled with acetone or alcohol. You don't need to take all the lacquer off, moistening it with alcohol is enough to soften its seal to allow tweaking the screw.

Give the screw a turn- to the right or to the left- one little turn is enough, and replace the lens back. Focus through the finder a very distant object. Usually, at this point, you'd still see focus errors. Take the lens off again and see which direction the screw should be turned to set the mirror correctly so that the viewfinder image coincides with the lens' focus.

If the lens focuses too close (infinity focus is achieved with the lens distance scale showing a shorter value), the reflex mirror needs to be lowered a bit. On the other hand, if the lens focuses too short (the lens is already at infinity, and the finder shows a close object in focus instead), the reflex mirror needs to be hoisted a bit. How much or how far will be determined by trial and error- turn the screw slightly in either direction until you see a "correct" image focused in the viewfinder.

Hope these will help.
Jay