Fixing Light Leak in Graphic Roll Film Back

[Kevin Crisp]

I finally got one of these, in apparently fine shape, and took a test roll with it today. All but one shot has evidence of a ruinous light leak. The one that didn't was taken in the shade, with me blocking the sun from reaching the camera. I was thinking I'd just tape around the edges when I load it up, but that would interfere with the slides locking it on the graflok back. Any other cures? Some really thin velvet like adhesive backed material would fit in the grooves and not interfere with the back but I don't know where to get something like that.

Thanks!

[Gary Beasley]

You might try moleskin. Is a cotton material used for blisters and such, can be found adhesive backed. You might want to blacken it with a sharpie after installing it.

[LabRat]

First, check the slide light trap for leaking by removing insert, take back housing assy into a dark room, and take a small bright flashlight to shine into where the slide enters the film gate area, and look carefully into the outer slide slot... Look near the ends especially for traces of light... Sometimes if the slide was in for a long time, it squashes the light trap felt inside... This will not come apart to fix, but there is something that has worked for a few backs that did this... If you rinse the slot with running water and a little dish detergent and let it dry for a couple of days, the felt fibers can bounce back up, and seal again, but on some worn traps, it might not work...

I noticed one back I am working on had some shifting around that could affect framing, so I measured the gap when it was shifted to one side and measured .040" gap, so I ran around the shop looking for some strips .020" black thick paper card stock and glued them to the outer edges of the back to center it, but also fill the gap to stop light from possibly leaking from the outer edges...

The hinge area looked a little sloppy with the gap, so I black photo taped a little flap over that...

Since the film gate is smaller than the back opening, I cut a thin foam rubber rectangle slightly smaller than the back opening to glue on the film back mounting inside to provide an extra baffle step and maybe help control internal reflections...

I've currently started shooting a Graflex 22 2 1/4 square knob wind back on a Super D RB 4X5, but currently have no processing facility, but shooting film, and worried about leaks, so I'm trying to minimize disaster when I get around to process the film...

But these things have worked on other backs in the past...

Good luck!!!

Steve K

[Kevin Crisp]

Thanks for your suggestions. I feel kind of dumb for not thinking of taking out the insert and checking it with a light in the camera. Duh. From the pattern it is definitely a leak on the long sides, not the dark slide felt.

[LabRat]

Don't feel dumb, as I have been adding light proofing now, and realize I could have been checking the mating areas I have been working on with light, instead of just shotgunning it, so I just learned something too...

But also check a thread from a couple of weeks ago about Horseman vs Graflex roll backs, where I posted some film path upgrades, as there can be odd random scratching of film sometimes, but can be stopped...

Have fun!!!

Steve K