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Re: What to do?....or Can I do this?

Phil Davis

19:26 1 Jul 04

Scratches on tube-developed film

David B. Mark

20:41 29 May 04

Today I returned to my darkroom for the first time in nine months (after changing jobs and houses, and adopting a child from China). The first order of business was to develop five negatives that I had exposed last year. I used BTZS tubes, which has been my preferred method of developing sheet film for several years now. Until today, I had never damaged film that I developed this way. Today, four of the five negatives had significant longitudinal scratches on the backs. One negative actually had three roughly parallel scratches of different lengths in the middle of the back. On another, the scratch was more diagonal and towards the middle top of the film.

The only part of the process where I was aware of having difficulty was in getting the developed and stopped film out of the tubes. Several of the films were reluctant to pull free even after I twisted a corner of the film away from the tube wall. My current hypothesis is that I pulled too hard on the wet film when it was adhering to the tube wall. However, I have had difficulty getting film out of the tubes in the past, and I have never seen scratches like these before.

Can anyone confirm that pulling too hard on the wet film when removing it from the tubes can cause scratches on the film backs? If this is the cause of the damage I am seeing what is the cure? The only trick I know is the one I used: pulling a corner of the film away from the tube wall. Finally, I learned on the large format forum that some people are putting pieces of nylon screen between the tube wall and the film. Does this help in removing the film from the tubes?