Hello...
I just got my film back from development and it all (16 frames, mix of E-6 and B&W) had major issues. Nearly all my shots had large washed-out streaks across most or all of the frame. There is no discernible pattern to it that would jump out and say "this is a holder problem" or "this is a film problem". I am tempted to send in some unused film out of the box and see if it is that. Perhaps the light tight box has a leak or opened at some point.

Does anyone know of a good way to test film holders for light tightness? I kept a notebook of shots compared with my numbered holders at one point, and found a bad holder that way, but it seems unlikely to me that ALL (or nearly all) of my holders would go bad at once. I have also been using a changing bag instead of a darkroom, though I usually change film in a darkened room with it.

Another possibility is time and motion. I carry my camera gear in my vehicle (it is always good to be prepared), and go hiking with it. I take care of my gear, but is it possible that slight pressure on the darkslide would open a light leak that would expose across a major fraction of the frame?

Some of the film sat in the holders for quite awhile, so if they are leaking, it would have had ample opportunity to fail.

It was a major disappointment to see all these ruined frames. I had some really good shots that are toast. Does anyone have suggestions for what to do?