dark area at top of Polaroid print

I've just dusted off my big camera and 545 holder after a "slight" 30 year pause and have been trying some Polaroid film which I just purchased.

Before using the holder I was careful to open it up and clean it carefully and rollers look and feel really clean and smooth.

I used the 545 in a 4X5 back mounted in the Linhof 5x7 --> 4x5 reducing back.

I've noticed a darker area at the bottom (long side) of the prints. It seems to be a dark band about .25 to .375 inch wide running the complete length of the print. It isn't featureless or foggy or washed out, and just looks sort of like the area got an extra stop or so of exposure.

It's consistent across several prints using a brand new box of type 57.

Area is not at all blotchy as I'd suspect if it was a problem with the developer not being spread cleanly. It isn't quite straight, but a bit wavy along the bondary with the rest of the print.

I can't find any apparent problem with the rollers. Do you think this is a problem with the holder? Any other ideas, such as speed of pull? Any suggestions appreciated.

Do you store the film flat? If you store the box on end, the chemicals can flow to one side of the pack and cause uneven results, but usually that would produce an undeveloped area.

Jim, Call Customer Service at Polaroid, I'd like to see thoes prints.

Darker, but not black? That strongly suggests something is shadowing the film along that edge (dark on the print is less exposure, or more development, backward from negatives). With a reducing back, the bellows is probably not a major candidate for vignetting -- have you checked that there isn't a loose felt/velvet light seal in the reducing back, or something sticking up from the *bottom* (remember, inverted image) of the camera further forward, partially shadowing the film? If the edge is fuzzy, a completely opaque blockage close to the lens could do this; if the edge is sharp, you have something close to the film that's blocking a percentage of light, like a filter.

Alternately, could you have a compendium shade getting into your field of view (top side, once you're forward of the lens), or the edge of the dark cloth? You're probably using a small aperture, with ISO 3000 film, so partial vignetting is tricky (the object would have to cross the aperture close enough that some light still gets past it).

Or -- could you have a light leak that's affecting the whole frame *except* that darker strip? Try (in the same light you usually shoot in) loading a sheet, pulling the envelope, and leaving the shutter closed for, say, five minutes, then process normally as for exposed film. If you see any part of the print that's lighter than max black, you've got a leak, and the bellows or part of the reducing back frame is shadowing some of the film from the leaking light.

Thanks for the suggestions

One thought I had was to rotate the 4x5 back (leaving the reducing back as is) and see if the dark band stays in the same place relative to the film or relative to the camera.

I don't think there are any cloth light traps - just the recesses in the metal backs.

Camera is a 5x7 Linhof Kardan Bi that I bought new in around 1970.

If the band stays in the same place relative to the film then it's a 4x5 back issue or film issue.

Could also try a couple of positions of the reducing back to see.

I'm not using either a compendium bellows or focusing hood. I couldn't see any apparent brightness variations on the ground glass, but who knows? I'll also try aiming a strong light at the bellows and see if I find any light leaks.

I'll check it out when I get back from this business trip on Wednesday or Thursday.