Testing 4x5 holders

[red_jenny]

SO what would be the most efficient way to test 9 used 4x5 film

holders (of various makes) for light leaks? I'd hate to have to find

out that one or more leaks after I spent the time and effort in

taking photos. On the other hand I don't want to waste film

needlessly either... I guess I can cut one sheet into several pieces

and insert them into several holders, but will that be sufficient to

check light leaks?

[scott_kathe1]

Load the film holders with the appropriate size black and white photographic paper. Expose the loaded film holders with the dark slides in place to light. Develop prints and see what you've got.

[red_jenny]

Aha! load it with PAPER not film! Brilliant!

[donald_hutton]

I'd take a single sheet of highish speed film - move it from holder to holder and place the holder in a very bright light (and move it around at every angle) for a couple of seconds with the film in place. Do this for each holder on both sides. When you finish and develop the film, you will know if there are any leaks and will have to test further (maybe with the paper method) to find out which holder is causing it. I would start with the presumption that your holders are all OK (unless there is a good reason to presume otherwise) and go from there. Remember, these things are designed to be light tight and I think I've only ever had one or two 8X10 holders which had very slight leaks (they were still usuable) - I've never had a 4X5 holder with a leak. A piece of high speed film will likely show every little issue - paper is very slow in comparison.

[danny_liao]

save your paper and film. simply take the dark slide out. point the slot into a light and look up into it. if you see little dots of light coming through, than the holder is bad.

[david_senesac]

Remove your lens from the front standard. Get a good bright flashlight preferably one with a narrow beam. Go into a dark room. Shove the holder into your rear standard slot. Get your eyes right into the lens slot and move the flashlight not only into the film slot of the holder but also all around the edges of the back checking for any sign of light leakaage. Jostle the holder around a bit in its slot too.

[tito sobrinho]

Red, I would agree with Scott. Load the film holders with photographic paper and expose all of them with their dark slides in the sunlight, shuffling them around. Mark the holders with numbers and a cuts on paper i.e. #1, one cut, #2, 2 cuts and so on. Develop them and you will know which holder is leaking light.

 

I did these tests in the '80s for my used 4x5, and 8x10 film holders.

 

Regards, Tito.