Ive posted about getting strange marks before, but this time im getting some that have almost no explanation. The marks are very odd, have somewhat of a pattern, a very defined density, and occur at random intervals that do not line up when the film is spooled on the reel or in the spool or in the camera. The batches of film are different. It will occur one a single roll of film but not others in the same tank. It ONLY occurs on HP5 if it does. Sometimes it leaks into the frame but is localized mostly to the sprocket holes. Definitely does not occur in the camera (Leica MP, very new, and no other film is ever affected, and sometimes the HP5 will be totally clean as well. If I can remember anything else, i've exhausted almost everything I can. The films it will occur on were not shot anywhere near each other. I would like to think its something I'm doing so i can eliminate it. attached are some samples of the problems
