Light Leaks from hell

[RPippin]

I'm having a hell of a time with light leaks from older 8X10 wooden film holders. I've tried traceing them down with a high intensity led light in the dark, found some, used B&S bellows patch liquid and recoated the hinge tape. Took the dark slide covers off, shimmed up the metal strip, cleaned them up, put them togather, re-shot some film and still got leaks. some still from the slots, some from the sides, basicaly all over the place. I've been replacing them with more modern holders as I can afford to, but would still like to solve this if possible before having a bonfire out of shear frustration. Any brilliant ideas would be appreciated, if not send yours to me and I'll add them to the fire and offer them up to the film gods.

[Brian Sims]

If it isn't too windy, I leave my darkcloth over the back of the camera and take the slide out under the cloth. Very few leaks even on sketchy holders.

[Daniel Stone]

check your camera's back as well.

wooden cameras can warp as well. put a film holder in and check the light-fastness of the film holder against the back where they touch.

+1 to Brian's rec of using the darkcloth over the back. Why I decided to give up the 'horse blanket' and tube-style darkcloths in favor of a lightweight rubberized cloth to use as my darkcloth.

-Dan

[RPippin]

Tried the high intensity led from the inside of the camera with a film holder in the back and this time saw light coming through all around where the holder seats to the camera body. What can I use to get a better seal? I've also tried covering the camera with the darkcloth before without success. This is an old Kodak 2D, by the way. I think this leak is pretty substantial with any film over iso 100. Am I doomed?

[mandoman7]

You're not doomed, but its upsetting to go to all that trouble with 8x10 only to have a potentially great shot ruined. You may not have the patience to go forever losing shots like crazy. One must protect their creative energies.
Bad holders must be discarded period. That insulating felt inside where the darkslides go wears out and is not replaceable. The hinge side is not usually the leak source. Holders are cheap when compared to the film that goes through them.
The holders must also seat well as you've discovered. That's pretty easy to check and fix. Not a common problem, though. In most cases you should get a good snap when it gets in position. You can find replacement backs on ebay if it is actually warped. An under appreciated problem that also happens is when the darkslide is removed the holder can get pulled back slightly and leak a little. Pinch the back when pulling slide.
Bellows leaks are bad news. Personally I would immediately replace ones that are suspect. Its not worth the aggravation or risk for loss of good shots. They can be tricky to test from all angles.
I would add that its worth the trouble to do a lot of testing IMO to gain some piece of mind out in the field. If I get new holders or new lens boards or whatever, I do not commit good film until I've shot some test shots around the house, or out in the sun. By notching and numbering the holders I'm able to pinpoint the problem areas before they ruin something important. I've ruined enough shots in 30 yrs. to know its worth taking the time to know you're stuff works.

[ic-racer]

http://www.largeformatphotography.in...l=1#post281854

Perhaps some useful info in this thread around post 74.

[AtlantaTerry]

used B&S bellows patch liquid...

I never heard of that product. Would you mind telling me more about it?

Thanks.

[AtlantaTerry]

Maybe it is time to purchase some new plastic 8x10 sheet film holders.

Donate your old wood ones to a museum.

[Keith Fleming]

I had similar problems with my 4X5 field camera. I sent it to Richard Ritter who not only fixed the ever-so-slightly-warped back but also checked to make sure the ground glass was positioned at the proper distance. No problems since then.

Keith

[RPippin]

I'm wondering if using some light felt or linen tape might act as a seal. I can't see any warpage with the film back and I know registration is an issue and don't want to screw up focusing on the ground glass. Seems like some wood shrinking could be the issue. My studio is pretty dry. There must be others with experience with a bit of loose fit with the film back to the camera body out there.