help diagnosing a light leak

[ndavid813]

Hi,

I'm having an issue with a light leak when I shoot my Nagaoka 4x5. Here are two examples:
http://farm3.static.flickr.com/2595/4127608694_2cb4e41f11_m.jpg
http://farm3.static.flickr.com/2656/4126836743_f4ff0669c2_m.jpg

The center of the pictures show evidence of a light leak somewhere. It is not the film back or holders - I get the same light leak regardless of orientation. It is also not the lens board since it happens with different lenses. I believe the bellows are light tight since I've done flashlight tests and don't see any evidence of pinholes.

I would appreciate anyone's insight on what is causing this leak.
thanks

[Jack Dahlgren]

You have ruled out film back, holders, bellows, lens board...
That pretty much covers it. Maybe your film got exposed when you were loading/unloading it.

Sure it is not a development issue? Looks blotchy to me, but the pictures you posted are too small to tell.

[ndavid813]

Thanks, the sheets were fujii quickloads and I sent them out for developing at different times. I've sent other film shot with another camera out to the same developer and not had the issue. I'm wondering if the camera is holding the lens board securely enough.

[Mike1234]

May I suggest you try a different lab?

[Andrew]

it's a similar camera to the tachihara and I heard people complaining about light leaks with those and sure enough when I got a tachi I had light leaks too !

you'll proably find light coming in between the light trap and the film holder because the recess is a bit "loose"... try taking the back off the camera, putting a film holder in and looking closely with a torch to see if you can spot a specific area of light leak[though in my case it's more like all over]