Suspected Shutter Problem in 300mm APO-Ronar

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I was wondering if any experienced large format shooters could comment on this. This photo is from a 4x5 shoot I did recently. It appears that my 300mm Rodenstock APO-Ronar (in Copal 1 shutter) is is malfunctioning in some way. There is a very weird light leak in the bottom right quarter of the frame, near the woman's lapel. This happened in multiple photos with the same lens. I don't think the camera body (Horseman 45LE) is leaking light because my other lenses didn't do this -- I used them at the same shoot with the camera in the same position. It's unlikely to be a flare, because it's not shaped like a flare; also, the Ronar is multicoated, and I was shooting under a cloudy sky. My best guess is that the shutter blades aren't closing back up at the same time, even though this is not observable when I test the shutter. (Shutter speeds sound strong and accurate.) Any help on this would be appreciated.

 

[E. von Hoegh]

I was wondering if any experienced large format shooters could comment on this. This photo is from a 4x5 shoot I did recently. It appears that my 300mm Rodenstock APO-Ronar (in Copal 1 shutter) is is malfunctioning in some way. There is a very weird light leak in the bottom right quarter of the frame, near the woman's lapel. This happened in multiple photos with the same lens. I don't think the camera body (Horseman 45LE) is leaking light because my other lenses didn't do this -- I used them at the same shoot with the camera in the same position. It's unlikely to be a flare, because it's not shaped like a flare; also, the Ronar is multicoated, and I was shooting under a cloudy sky. My best guess is that the shutter blades aren't closing back up at the same time, even though this is not observable when I test the shutter. (Shutter speeds sound strong and accurate.) Any help on this would be appreciated.

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Well, that's one thing it most certainly is not.
It looks like a bellows lightleak, or perhaps a leak in the lensboard. Something appears to be focused there, perhaps treelimbs, as though a lightleak somewhere is forming a pinhole-type image.
Check the bellows (and the rest of the camera) carefully, if shorter focal length lenses did not exibit this problem it could be that the bellows were not extended enough to bring the leaky part into play.

 

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Thanks! I'm not an experienced LF shooter, so I'm only figuring out the technical difficulties associated with the equipment. I'll do a thorough check of the camera/bellows for leaks.

 

[E. von Hoegh]

Thanks! I'm not an experienced LF shooter, so I'm only figuring out the technical difficulties associated with the equipment. I'll do a thorough check of the camera/bellows for leaks.

Take the camera into a fairly dark room and remove the back and lens. Put a small lightbulb into the extended bellows, look for pinholes along the edges of the bellows and wherever they fold. Don't be too surprised if it lights up like a planetarium; this is what darkcloths are for.

Edit - Be persistent, move the lightbulb (a Christmas tree light will do, small flashlight, etc.) around, leaks can be hard to find. If they're there, just wrap the darkcloth around the camera. I've been using a Deardorff with a leak in one corner of one pleat of the bellows since the late 1980s, the result of mishandling. I keep saying I'll patch it but never seem to get around to it...