Identifying source of light leaks

I'm rather dense and I plod along, however, a suggestion or two by fellow forum members may "enlighten" me. I'm dealing with a old LF Scovill field camera and fabricated custom cut Rochester holders 6 1/2 X 8 1/2) to accommodate to the camera back---and the deal is "light leaks". I'm trying to identify whether: 1. the bellows leaking light on film, 2. the holders leak light on the film---(film in this case is 5x7) and or both. I'm in the testing stage now and film is being "exposed" at this time.

Presently, the testing done at this point shows "light damage" to the negative on processed film, approx 8 sheets of film---be it bellows or film holder. Presently, I have a test---a film holder, with film, in camera with its "slide" pulled out, bellows extended, and lens cap on rear & front on. Need to process this one sheet of film when the "soup" will be available.

Based on the limited info above, what suggestions would you have re: the identification of light leaks--be it bellows or film holders?

Raymond

Begin by placing the camera in a dark room. Extend the bellows and remove the back. Turn off the light and wait 5 minutes for your eyes to adjust to the darkness. Then cover the rear of the camera and your head with the dark cloth. Hold a small light bulb and move it around the camera, and in front of it. Any light leaks will show up.
I also remove the lens, replace the back and insert a film holder then put a small bulb in the bellows from the front. This will enable you to see leaks around the holder.
Scanning a negative or two and putting them on this forum can also help find the leak.

The test for the holders is a no-brainer... Put old film or paper in them and bring outside for a few minutes, then develop...

That should answer that question...

Steve K

oops sorry jim. i see you got this already.

also.... put the bright light inside the camerathrough the lens board hole, leaving the back on in a dark room n look around the bellows, especially the corners of the folds and at every edge of the body. put a film holder in and check to see any leaks there.

good luck.