Strange Wiggle -- What is IT??

[fraley]

One of my Zorki's displays a wiggle on the top of the picture, especially when it's a bright background such as a sky or light wall. I checked past rolls and it appears consistently regardless of lens.

Since it appears as a whiter wiggle, rather than a yellow flare, I'm guessing it's striking the front of the film not the back. What could be causing it?? Have you ever seen anything like this?

I had another Zorki with a vertical white stripe -- which I eventually determined was caused by a gap in the shutter curtains that allowed light in when winding on. But this one is a wiggle worm and is horizontal.. what can it be?

 

[fidget]

Does the line (is this the pattern that looks like a jet trail?) extend outside the frame?

Dave

 

[mcgrattan]

I had exactly the same thing on an Agfa Optima I had. However, that had a vertical travel metal shutter so I always assumed it was a tiny gap in the shutter curtains.

Is it possible there's a tiny light leak around the lens mount? At the base?

 

[payasam]

Had something similar with a Leica IIIc, with only those frames being affected which were in the gate when I changed lenses. The lower light shield was the culprit. Easily fixed.

 

[fraley]

Thanks everyone,

the 'jet trail' doesn't appear between frames.. I will look again at the lens mount and lower light shield -- if I can figure out what that is ! 🙂

 

[fidget]

Thanks everyone,

the 'jet trail' doesn't appear between frames.. I will look again at the lens mount and lower light shield -- if I can figure out what that is ! 🙂

It seems to be entirely within the frame, but fairly even along it.
I would suspect as Payasam has suggested, the lower light shield.

You didn't tell us which model this is.

 

[fraley]

Sorry! This is an early Zorki 4, the kind that has the 5/10/25/50/100 shutter speeds, and a "window frame" around the front viewfinder window. Cryllic engraved camera model name on the front.
There's a piece of metal on the lower front side, then the curtain, then the back housing where the film travels. In this channel that the curtain travels, there's some felt or some kind of cloth. It has an irregular top edge that more or less looks like the 'jet trail' on my negatives -- a wavy line. Would I try to add more material there?

 

[payasam]

I'd say you've found the problem, fraley. Whatever you add should not (a) obstruct the shutter curtains or (b) shed fibres, as the feline in your "avatar" probably does.

 

[fidget]

I'm not sure if the material is a standard fit on the older Zorkis (I've only seen this on much later FEDS).
Sounds as if someone may have tried to cure this problem.

That gap must be wide enough for the overlapping curtain laths to pass along it.
If there is more gap than this, you could try to close it a little, trying to cock the shutter each time.

Try "looking" at the back of the cocked/uncocked curtains whilst shining a torch into the empty lens mount (in a dark room). If you are able to see some light ingress, you will at least be able to check your fix.

Dave

 

[wolves3012]

I just had a look amongst my collection and there is a foam of some sort fitted to the back of the lower light-shield on my FED 5C but not on any other FSU I own.

As fidget suggests, try moving the lower light-shield a little closer to the curtains before adding foam or felt. I've never seen this fitted to a Zorki and I suspect that it will wear away quickly and possibly drag on the curtains or laths, interfering with shutter action.

 

[fraley]

Thanks again, I moved the lower light shield closer to the curtains. I'll take a test roll next.... I've got two Zorki 4's that look identical in this area, although the good one did appear to be a closer fit. So maybe this will be a simple fix.. fingers crossed.