Are my negs bowing?

[jonathan_lipkin]

On quite a few of my negs, the image appears 'bowed' on the side away from the notches. In other words, instead of a perfectly straight line where the image ends and the film base plus fog line appears, it is slightly curved, with the center bowed out away from the rest of the image.

It's not on every image, maybe 20%

I'm not quite organized enough to say that this happens with a particular holder, but it does occur on multiple images from the same shoot, so not just one holder.

Does this mean that the film is curved during exposure? And if so, is this a problem? I usually shoot at very small apertures - f/45-f/64 - so would depth of field take care of any difference in the film plane depth?

[Jack Dahlgren]

On quite a few of my negs, the image appears 'bowed' on the side away from the notches. In other words, instead of a perfectly straight line where the image ends and the film base plus fog line appears, it is slightly curved, with the center bowed out away from the rest of the image.

It's not on every image, maybe 20%

I'm not quite organized enough to say that this happens with a particular holder, but it does occur on multiple images from the same shoot, so not just one holder.

Does this mean that the film is curved during exposure? And if so, is this a problem? I usually shoot at very small apertures - f/45-f/64 - so would depth of field take care of any difference in the film plane depth?

I've seen this too, but I think it is because the opening of the film holder is curved at the end. The curvature is to extreme to be caused by buckled film. Check your film holders. Mine are full of film right now so I can't confirm.

[Vaughn]

Is the curved line sharp? Might be a slight shadow caused by sagging bellows.

[jonathan_lipkin]

Yes, they are sharp. And too symetrical to be caused by bellows, I think. Plus they are on the side (shot horizontally) so gravity would not be pulling sideways. I'm not at home now but I'll check my holders when I get back.

[Vaughn]

It was a long shot. I think I have holders that have given me that curve, now that I think of it. It has been a long time since I have shot tiny little 4x5's. (just about to develop a couple 7x17 negs I shot this afternoon in the redwoods).