10 x 8 camera light leak? help

[leeb]

yep me again, looking for answers....

we have a 10 x 8 toyo field camera, when taking shots outside, we appear to have a light leak which starts about 5mm into the right hand side of the image (left of the neg) this is the far side of the film holder. i have had the camera in the dark room, and had a otrch on every possible source of light leak. it has been on a lot of the negs, so isnt a problem with just one holder. the far 5mm seem to be exposed correctly so that would suggest it is being shadowed from the leak, but i can just not find aby source of light entering the camera where it shouldnt be. have tried it with a neg in, without a neg in no dam joy. the only way light comes in is via the open lens when it is meant to be. i have even put the slide in, taken out the sheeth so as to expose a neg, and shone a torch into the side, front, back and there is no light whatsoever getting through the sides etc. but wee keep having the problem!!!!

anybody out there had a similar problem, i would very much appreciate some suggestions as its driving me mad trying to second guess what it could be.

Thanks a lot.

Lee

[sdws]

Can't quite picture what you are describing but does it look like fogging or is it sharper? Pinhole in bellows, the bellows nor being seated properly or the dark slide not locating properly in the standard have to be favourites. Do you leave the sheath in the end of the ds when exposing it is not unknown for light to leak past the dust traps. Don't forget that film will likely register light you cannot see.

Edited by sdws on Monday 16th April 16:30

[tog]

leeb said:

i have even put the slide in, taken out the sheeth so as to expose a neg, and shone a torch into the side, front, back and there is no light whatsoever getting through the sides etc. but wee keep having the problem!!!!

Try that in bright daylight, remember a torch is not very bright in the big scheme of things. Leave the sheath removed but shutter closed for several minutes and develop to see what you get. Repeat with all your darkslides.

[Bacardi]

Difficult without seeing a sample, can you post one? Here's a few more thoughts.

Does the shape/size/position/amount of the fogging change from pic to pic? Does it do it every time? If it happens using different DDS that kinda rules them out, although if they are old, the fabric on the hinge can get worn, although, like the slide/lighttrap side this would be very rare. The bellows would be most likely. Have you put the camera in a black room with the bellows extended as far as possible then shine the touch inside the bellows? Make sure the inside of the bellows are clean.

Double check the mounting of the back and lens panels. If the bellows are interchangeable, check the mounting of them as well. Does it happen with different lenses? Apeture/shutter blades all OK?Have you tried loading film, pulling out the DS, putting back in and process without making an exposure with the lens?, Could the film get fogged in the loading room? Is this all with the same batch (as in batch number on the side of the box), of film?

What make of DDS? No problem with loading the film? i.e. if it doesn't go all the way in properly the hinged flap will be slightly raised on it and won't sit quite flush with the body of the slide. Makes the DS stiffer to locate into the groove at the end so you should know if you done that.

[S. Gonzales Esq.]

Not sure it's relevant in this case (not many components inside a 10x8) but I've experienced flare issues with a Hasselblad. One part that was supposed to be matt wasn't, resulting in consistent flare on the film.

I spent ages looking for a light leak before I worked it out.