Go get your changing bag (dark bag) and check for light leaks, now. This is prompted by two incidents, one just recently here at Photrio, and another about a year ago at the Large Format Photography Forum. I’ll be posting about this on both sites.
https://www.photrio.com/forum/threads/strange-problem-with-my-developed-film.201108/
https://www.largeformatphotography....the-source-of-this-light-leak-on-my-negatives
In both cases, the changing bag was found to be grossly leaking light, but it took a long time, and considerable cost, to discover the primary issue. Like most people, I never considered changing bags to be a major problem, but in both these cases the changing bags were relatively new, so they were never suspected.
Testing your bag is very easy. You just need a bright flashlight to put inside your bag. With the room lights off at night, put your hands in the changing bag and turn on the flashlight. Move the flashlight around in the bag, and see if you can see any light coming through. Hopefully you don’t see any light coming through anywhere, but if you do, then those are leak points where light could come through to expose your film in unexpected ways.
It looks like changing bags have become very popular now with new film users, since you can develop film in a tank without needing a darkroom. With digital film scanning, this now becomes an attractive option for many people.
Over the decades I’ve collected several changing bags of varying size. I have one in my large format camera pack, to act as some camera padding, but also for emergency use if I need to load film holders in the field.
I decided today that I’d better check all my bags to see if they’re safe to use. The news was not good. The bag that I keep in my camera pack was leaking light at the zipper, and the material used in the sleeve sections was semi translucent. I found two other bags that were full of leaks and should never be used, but they looked fine cosmetically. I found a couple of bags that had a few pinhole leaks that could probably be O.K. in a darkened room, or could possibly be patched. Fortunately, I did find a few good ones, and I’ve put them in plastic zip-lock bags with the date tested. Age is not the primary consideration. Only one bag that I have has a manufacturer’s label. That one was a very large Burke and James bag that was still light tight. That one had to be as old, or older, than me.
One thing that I was shocked to discover is that only one of the layers is light tight. I thought the double layer bag was a safety measure to protect light leaks if one layer goes bad. This is NOT the case. In every single bag I checked, one of the layers is a very thin woven material that provides no light protection at all. I can see the whole flashlight through it. It’s about as effective at blocking light as a one stop neutral density filter. I couldn’t believe it, but that’s they way they’re all made.
Anyhoo, film is too expensive these days to be farting around with, so go check your changing bag.
https://www.photrio.com/forum/threads/strange-problem-with-my-developed-film.201108/
https://www.largeformatphotography....the-source-of-this-light-leak-on-my-negatives
In both cases, the changing bag was found to be grossly leaking light, but it took a long time, and considerable cost, to discover the primary issue. Like most people, I never considered changing bags to be a major problem, but in both these cases the changing bags were relatively new, so they were never suspected.
Testing your bag is very easy. You just need a bright flashlight to put inside your bag. With the room lights off at night, put your hands in the changing bag and turn on the flashlight. Move the flashlight around in the bag, and see if you can see any light coming through. Hopefully you don’t see any light coming through anywhere, but if you do, then those are leak points where light could come through to expose your film in unexpected ways.
It looks like changing bags have become very popular now with new film users, since you can develop film in a tank without needing a darkroom. With digital film scanning, this now becomes an attractive option for many people.
Over the decades I’ve collected several changing bags of varying size. I have one in my large format camera pack, to act as some camera padding, but also for emergency use if I need to load film holders in the field.
I decided today that I’d better check all my bags to see if they’re safe to use. The news was not good. The bag that I keep in my camera pack was leaking light at the zipper, and the material used in the sleeve sections was semi translucent. I found two other bags that were full of leaks and should never be used, but they looked fine cosmetically. I found a couple of bags that had a few pinhole leaks that could probably be O.K. in a darkened room, or could possibly be patched. Fortunately, I did find a few good ones, and I’ve put them in plastic zip-lock bags with the date tested. Age is not the primary consideration. Only one bag that I have has a manufacturer’s label. That one was a very large Burke and James bag that was still light tight. That one had to be as old, or older, than me.
One thing that I was shocked to discover is that only one of the layers is light tight. I thought the double layer bag was a safety measure to protect light leaks if one layer goes bad. This is NOT the case. In every single bag I checked, one of the layers is a very thin woven material that provides no light protection at all. I can see the whole flashlight through it. It’s about as effective at blocking light as a one stop neutral density filter. I couldn’t believe it, but that’s they way they’re all made.
Anyhoo, film is too expensive these days to be farting around with, so go check your changing bag.