I posted this on the large format photography forum and they suggested that I post it here as somebody from Ilford visits here.
I have a problem that I thought was me at first but now I am thinking it is something wrong with Ilford film. I shoot HP5 across all formats, and recently in the last few rolls of 120 I have gotten wavy lines that run across the non emulsion side of the film. At first I thought it might have been the camera that I was using, but then I developed another roll that I had put through a different camera. The lines looked the same. Then I thought it might have been from me squeegeeing the film so I stopped doing it and the lines were still there. So I figured it was something with the medium format film I had. But then I just developed 2 sheets of 4x5 HP5 and the same lines were there. The lines ran straight across the whole sheet on the non emulsion side. With my sheet film nothing touched the film at all except for liquid and its time in the film holder. I didn't squeegee the film nor did I touch it with anything and the lines are almost the same. I have attached three photos that you can see the lines in on a sheet of film as well as from a roll of 120. Has anyone ever seen anything like this and what could be causing it? For the record both films were stand developed in Rodinal for 1 hour with minimal inversions at the beginning and 2 inversions at the half way point. Dilution was 1:100.
http://www.flickr.com/photos/alex1345/9522582212/
http://www.flickr.com/photos/alex1345/9522582882/
http://www.flickr.com/photos/alex1345/9522582806/