light leak in holder or reflections?

[pellicle]

Hi

looking at this scan of one of my sheets you can see some evidence of fogging in the corner (where the bottom trap door is and the film dent is).

the sharp of eye will also notice a halo around the edge of the film, about as far in as the border is deep (which is along the top, where the darkslide inserts).

The funny thing is that I can leave it closed on a desk all day long and develop a sheet and never see a trace of it on the blank sheet. so this makes me think that its coming in only when the darkslide is removed ... I have tried also keeping my dark cloth over the back of the camera (meaning light is coming in mainly via the lens) and still get it.

The holder is a Lisco Regal which is old enough to have an alloy top on the darkslide (and I bought it on eBay some little while ago).

if its reflections how can I minimise this?

Paint seems so ... crude

 

[Robert Hall]

I have a couple of older film holders that have a similar leak near the bottom. If it were more than just the couple, I would probably blame my ability to seat the film holder correctly.

while it could be light getting around the film holder while in the camera back, I wonder what kind of camera you are using and how old or what shape the camera back and bellows is in currently? I would also wonder if the bellows may be poorly attached to the cameras front and/or rear standards?

Images of the camera as well as the camera back might help in getting a better idea of what is happening.

Regards,

 

[Bruce Watson]

Since you don't see this problem if you don't pull the darkslide, we can more or less safely eliminate the film holder as the problem, yes? That is, you don't have light leaks through the hinge tape, etc.

So... An easy test to run -- put the filmholder in the camera, close the lens iris, and pull the darkslide. Give it as long as you want, reinsert the darkslide, flip the holder, and make an exposure with the other sheet.

Now, if you see your fogging on the unexposed sheet, it's more likely to be something about the camera, or the way the film holder seats in the camera.

If you don't see your fogging on the unexposed sheet, but you do see it on the exposed sheet, it's probably a reflection inside the camera. I've seen something similar to this from film holders -- light reflecting off the smooth edges of the film hold down rails. A little light sanding to take the luster off fixed it right up.

Could be a lot of things unfortunately. But maybe this kind of testing will help narrow it down some.

 

[Robert Hall]

And try it with Paper, instead of film. It's easier and perhaps cheaper.

 

[pellicle]

Bruce

So... An easy test to run -- put the filmholder in the camera, close the lens iris, and pull the darkslide. Give it as long as you want, reinsert the darkslide, flip the holder, and make an exposure with the other sheet.

Now, if you see your fogging on the unexposed sheet, it's more likely to be something about the camera, or the way the film holder seats in the camera.

If you don't see your fogging on the unexposed sheet, but you do see it on the exposed sheet, it's probably a reflection inside the camera.

I have essentially done just that ... so

I've seen something similar to this from film holders -- light reflecting off the smooth edges of the film hold down rails. A little light sanding to take the luster off fixed it right up.

I'll give it a go ... can't detract from their value ... seems better than pen or paint too.

thanks