Possible 4"x5" film holder light leak?

[Tom Kershaw]

I've just started using my 4x5 camera again and came across this problem which I'm approaching as a light leak issue but perhaps I should be looking at something else...

Any ideas? - Toyo film holder. TMY-2 film / XTOL 1+1 - Jobo 3010 tank.

 

[shutterfinger]

1. ensure that a film holder sits flush to the back on all sides. small amounts of debris in the corners and light trap of the back will prevent the film holder from seating properly.
2. install the suspected faulty film holder, remove the lens board, and take the camera into total darkness.
3. shine a very bright light inside the camera and observe the exterior.
4. pull the darkslide on the camera side of the film holder.
5. anything other than totally black is a leak.
6. old school was a 40 watt appliance bulb in a small lamp. cfl's and led bulbs work. hot bulbs will burn the bellows if touched.

 

[Tom Kershaw]

Thanks. I'll investigate and report back.

 

[Dennis S]

When I started back shooting and developing 4x5 I was getting those annoying little light leaks on my film. Tried all the things suggested to me by members here with no success. Turns out what is was was when I got the developing tank and was using the 'taco" method of developing, the post inside the tank was the wrong size and light was getting in between the lid and the post. Using the MOD54 method now with a new tank with no light leaks. So the point being check your whole system from shooting to developing to eliminate this problem. Good luck.

 

[shutterfinger]

Jobo 3010 does not use a center column. https://www.jobo.com/analog/3010-jobo-expert-drum-10-
Not that it can't weal and leak but its highly unlikely.
Mod 54 only wishes it was this good.

 

[Tom Kershaw]

Some FP4 Plus I shot of the same composition also shows this artefact so somewhat suspicious of user error on my part.