Light Leak Problem

Hi,

I've had a couple problems with light leaks with my Arca-Swiss F series camera. It's an isolated problem that has only ruined a few photos so far (a few too many though), and I was just wondering if you might be able to guide me in the right direction. I have attached the images that have been affected the worst.

I haven't kept the best notes, but I'm fairly certain that the images worst affected are from my 90mm f6.8 Angulon. I have checked it many times to make sure that the blades aren't sticking and I haven't seen it happen. I think this is the problem for the image with the hard edged light leak at least. Where can I get a CLA in Canada (Maritimes) or New England?

My other concern would be with the light seal around the lens board and the front standard. It's a foam, and it's not flaking away like I have seen in other situations but it is bent over, and probably isn't making the best seal any more. Where can one find this product?

Attachment 103182Attachment 103183Attachment 103184

Other notes: I have checked my bellows for any leaks and it seems fine. Some other images have a very slight light leak in the same part of the image, but I am not sure if they are with the same lens. Could it be the film holder? I've been learning in a vacuum (I don't know of any LF users in my town or area) so I'm not sure if there are any simple tricks that I'm missing when I place my lens board or film holder.

Thanks for your help,
Sean

If I had to guess I would say that the light leak came from the back. Either the film holder is not seated properly (it shouldn't be able to move), or you moved it when removing the dark slide, causing the light leak. Try gripping the back of the camera with your other hand, so the film holder can't move during that action.
I don't think this comes from the lens or front of the camera.

Quote:

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Originally Posted by JeRuFo

If I had to guess I would say that the light leak came from the back. Either the film holder is not seated properly (it shouldn't be able to move), or you moved it when removing the dark slide, causing the light leak. Try gripping the back of the camera with your other hand, so the film holder can't move during that action.
I don't think this comes from the lens or front of the camera.

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I agree. If the leek was on the front with the lens I would expect it to reach more of the full frame of the film.

Notice how the leek is along the bottom of all the images this means that it would becoming from the top as the image is flipped upside down on the ground glass. Put a film holder in the camera a check to make sure it is being held tightly at the top of the camera.

In the far right image the leak is clearly square cornered with distinctly straight sides. If you look at the other images you'll see that the other leaks are identical in shape and position but less sharply defined. I think this confirms what Zak and JeRuFo said. For some reason the film holder is pulling away from the rear standard. Either not fully seated or being pulled away when the dark slide is being removed.

Thanks for the help.

Thinking about it a little more that does make the most sense for it to be at the film holder. The leaks look similar to when I accidentally pulled a dark slide. Also the leaks seem to appear on sunny days, which is when I usually remove the dark slide with the dark cloth still on the camera which leads to a little more fumbling.

I'll check out my film holder seating with a flashlight tonight.

As mentioned, it probably is caused by the film holder not being firmly seated. This can also cause the image to be out of focus in that same area. Keeping the dark cloth over the camera at all times is insurance against light leaks such as these.

These leaks can sometimes be located easily. Here's how I've done it on a several of my cameras . . .

Put a white piece of paper in lieu of film in any suspect holders.
Remove the lens or lensboard from the camera.
Extend the bellows.
Attach a dark cloth to the "front standard" of the camera.
Put on some dark sunglasses.
Take the camera on a tripod, and holders outside into the bright sun.
Insert your film-holder and remove the darkside.
Put your head under the dark cloth while peering in through the front of the camera. You're looking at the white paper.
Remove your sunglasses. Your eyes may need some time to adjust to the dark.
Try to prevent light from leaking in around the dark cloth.
With the camera properly positioned you are likely see a glow on the paper.
Try to isolate the leak by blocking the sun with a hand.
Put on the sunglasses and swap out holders as required to locate leaks.
etc . . .

This can also be done indoors with a bright light source. But I've found using the sun is less of a hassle. With the bellows extended, pinholes can also be located. The sunglasses are important because it does take some time for your eye balls to adjust to dim light situations. Placing the camera in a darkened room, with a bright light source inside the camera is also another method for locating leaks.

Are we sure the problem isn't "darkness" leaking out of the camera?

DannL,

That sounds like an interesting technique.

DannL,

That is just outright clever!!!! Sounds like it would be a big help if you had a friend do the switching of holders while you stay in the dark under the cloth so your eyes can stay adjusted to the dark.