Vertical banding on IIIc negatives so....

[eli griggs]

let's trouble shoot and run down common Barnack light leak sources.

I know from other threads this is a light leak but I'm not sure what is the most likely source. The leak is about in the middle of the frame, but slightly to the right when view on a print, and seems to be only on the frames which were left for a few days between exposures.

In other words, frames that were shot together in fairly short order were not affected by the leak. I'll add that at first I thought it was from bracketing shutter speeds toward the low end but that doesn't seem to be logical, however, not knowing I could be wrong...

All five screws are in front, two in back and one on the right side and I can't see any areas on the top or bottom plate where it is pulled away from the body. There is no self-timer. Before I had this, it was CLAed by Youxin Ye and has given me no trouble at all.

Is it more that the problem is from the shutter dial or rewind lever or perhaps the slow speed dial... what's your idea and how do I fix it?

Cheers

 

[CameraQuest]

bad curtains.
replace them.

Stephen

 

[eli griggs]

Stephen, could you elaborate on that a bit?

Eli

 

[john neal]

Eli,

Need more info to provide a proper dignosis, I wouldn't automatically assume it is the curtains - if you wait longer between winding on, is the leak worse? If you always apply the lens cap between shots and especially when you wind on, do you still get a leak? Do you have a case you can use to block off the lower body for some shots?

More info is good, some samle pix migh help too 🙂

 

[John Shriver]

Look at both shutter curtain edges. If they are shaggy or uneven, you will get problems with uneven exposure at high shutter speeds.

Also, watch through the lens opening while you wind the shutter/film. See that the two shutter curtains remain overlapped by the full 3mm all the way across the frame.

 

[payasam]

"... and seems to be only on the frames which were left for a few days between exposures.

"In other words, frames that were shot together in fairly short order were not affected by the leak beyond the occasional."

Confusing.

 

[eli griggs]

"Confusing."

You're right Payasam and I'll edit out that part.

I forgot as well that the seller of this camera informed me that Youxin Ye had installed new curtains when it was CLAed and as I have no doubt that is a fact, I am resistant to the notion that they have failed materially.

Other than having the camera sit, without case, I haven't gotten one yet, it looks to me like a lower shutter speed might be the problem, if it's not an actual leak.

IIRC, I might have bracketed these few shots from a low shutter speed upward, something below 1/30th. I've a roll of Tri-X in it now, pushing to 1250, so I'll run through from a 1/10th up and see what happens, as well as shoot a marker for the frame that's resting in the camera now, and then take it out in bright sunlight for a few minutes and see what happens.

I'll also watch as I next advance the film to see if the curtains remain closed, to eliminate that possibility.

I'll post pics as soon as I can find the power cable to the $&#**^% scanner, if I can find it.

Thanks for the input and keep it coming. I think we should put together a sticky of the most common light leaks for these cameras, with pics, to make it easier to trouble-shoot; what do you think?

Eli