Fixing Zenit light leak

Huss · Mar 11, 2017

I got my test roll back from my brand new Zenit 12SD.
Exposures great, film spacing great, lens is sweet.
But.. there is a light leak. Same spot on every frame - top right corner.
This seems to match up with the placement of the camera strap lug, which goes all the way through. Pics attached.
So how do I fix this in a 'professional' looking manner? I really like the camera.

Thanks.

shutterfinger · Mar 11, 2017

1. Paint the area with Golden Heavy Body Acrylic Artist paint #1040 Carbon black. It can be diluted 1:1 with water and applied in thin coats to achieve the desired density.
https://www.goldenpaints.com/products/colors/heavy-body/carbon-black
2. Black RTV sealant spread thinly over the area.
3. Remove the lug, make a thin rubber or fiber washer to fit under the lug then reinstall.

Huss · Mar 11, 2017

Thanks, I think I will go w the black RTV sealant. It will be pretty hard to apply it on the inside as there is very little room, and it tends to cause threads of the stuff.
The lugs are a little loose as I can rotate them slightly by hand. But they look like rivet fit, no screw in so I don't want to remove it to find I cannot put it back in properly.

Does the location of the leak make sense that it is from the lug? The image will be upside down when projected onto the film through the lens. Which suggests the leak from the lug would be at the bottom of the final image, not the top.

Huss · Mar 11, 2017

Don't bogart that joint my friend, pass it on over to me.

shutterfinger · Mar 11, 2017

That top right in the photo is the bottom left on the camera with the film in place.
Post pictures of the rear of the camera with the back open if you need more help. There's not much available on line in terms of good back open pictures or owners manual.
A bright pin light with the lens removed in total darkness may be needed to find the leak/reflection.

Patrick Robert James · Mar 11, 2017

If it is on the exact same spot that points to a shutter curtain issue. You might have a hole in one of the shutter curtains if it is fabric. My guess would be it is the first curtain. I really doubt it is the lug.

Huss · Mar 12, 2017

Patrick Robert James said:
If it is on the exact same spot that points to a shutter curtain issue. You might have a hole in one of the shutter curtains if it is fabric. My guess would be it is the first curtain. I really doubt it is the lug.

It is. Guess moths must have got to this NOS camera... I'll see if I can locate the spot on the shutter and then do one of those rubber cement fixes.

Huss · Mar 12, 2017

Looking at the curtains, they really look brand new. As they should. But while I get the shutter curtains could be the issue with an RF camera, this is an SLR that has the mirror blocking the majority of the light coming through until the shutter button is pushed and the mirror flips up.
Either way, how do I check the curtains? With an RF I'd just go into a dark room and shine a light into the lens mount. But this SLR does not have a way to flip up the mirror w/o operating the shutter, so how do I check it?

shutterfinger · Mar 12, 2017

You should check it the same way as you would check a RF camera. Take the lens off and in total darkness shine a bright light in through the lens opening being sure to check the edges of the mirror not just the center while observing the film plane with the back open. Next shine the light onto the first curtain, shutter cocked, while looking into the lens opening then release the shutter and check the second curtain. Next lock the shutter open on B with a cable release, shine the light in through the viewfinder eyepiece and observe the film plane. Close the camera back, shine the light around the back edges while observing through the lens opening. If nothing shows up then slowly cock the shutter and check the mating of the two curtains.
Cloth focal plane shutter curtains are made from silk or nylon coated with a thin coat of black rubber. Occasional pin holes do occur in the manufacturing process as do thin areas. The artist paint listed in post 2 is better than RTV for curtain coating repair. Dilute and paint 2 or 3 thin coats on the cloth side for best results.

AgX · Mar 12, 2017

As seen in that picture that lug is riveted to the body. It is very hard to imagine light passing even if the rivet should have a fracture, what it has not.

Huss · Mar 12, 2017

AgX said:
As seen in that picture that lug is riveted to the body. It is very hard to imagine light passing even if the rivet should have a fracture, what it has not.

Yeah it makes sense it is on the curtain at it is in the identical spot on each frame.

trythis · Mar 12, 2017

You are using a Zenit, the leak is a feature. If you repair the shutter leak, it will strip a gear or the shutter currain will come lose! Maybe a knob will fall off, but these things are part of the joy of Zenit.

Huss · Mar 12, 2017

trythis said:
You are using a Zenit, the leak is a feature. If you repair the shutter leak, it will strip a gear or the shutter currain will come lose! Maybe a knob will fall off, but these things are part of the joy of Zenit.

Your tag line suggests you are a Zenit owner? Welcome komrad!

trythis · Mar 13, 2017

Huss said:
Your tag line suggests you are a Zenit owner? Welcome komrad!

I did own three 12XP's and two of them worked for a while and then quit after less than the entire first roll of film . I wanted to use the third one but decided that I could sell all three as a lot if the one still worked. Not using it worked pretty well for that. I am sure the buyer was able to at least load it with a roll of film before it broke and they had two more 12xp parts cameras even though none of the three cameras had interchangeable parts. (All of this was fully disclosed in the auction, by the way.)

I actually do like Zenit SLR's because when I find them while visiting my wife's family in Denmark, they often come with East German Ziess glass that I can sell when I get back home. It was really fun selling a couple of the lenses on ebay for a significant profit and selling the pile of bodies for what I pay for one of them at flea markets. Very useful.

Huss · Mar 13, 2017

Thank you for your valuable efforts komrad in insuring the spread of our glorious Soviet kameras.

Huss · May 11, 2017

I followed the advice of painting the shutter curtains. And success! No more light leak.

Thank you apugers!

blockend · May 11, 2017

There's very little wrong with Zenit cameras from a design perspective, it's just that by the time the 12 emerged production line workers didn't give a hoot. The UK importer used to test every camera before sale, and export cameras were made to higher production standards anyway, so Lord knows what the domestic issue gear was like! Apparently Kiev sold the same model rangefinder to local and export standards, but the domestic models were so bad it cost the owner the same price as one destined for the west in repairs. At one point they were so poor officials insisted the whole production quota went straight to landfill.

As a guide the earlier the better with Russian cameras, and some were very good indeed.

Huss · May 11, 2017

My 12SD is nicer made and featured than my TTL. But the TTL has a softer shutter release.

Fixing Zenit light leak

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