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View Full Version : Light leak, camera, or darkroom issue



jackbaty
11-May-2013, 08:18
I recently bough a new (to me) Burke & James Speed Press so that I could give 4x5 a shot. The attached photo shows 3 of the exposures (out of 8 or so) and demonstrates that I have work to do.

All negatives seem both way overexposed and subjected to a light leak. The image shows the negatives on a light table. Just holding them up, they appear almost completely opaque at first glance.

The first two were processed in a JOBO CPA-2 and 3010 drum. The third was tray processed. Two different film holders were used. Exposure times were varied by several stops (via shutter speed changes). The shutter speeds used (from 1/25th to 1/200th) *sound* about right, or at least they sound quote noticeably different from each other. For example, the 3rd negative was shot at f11, 1/200th. Another exposure taken immediately following was taken at f11, 1/30th. They look nearly identical.

The dark band on the bottom suggest to me a leak between holder and camera, but I'm new to this so I thought I'd ask here.

Thank you.

94864

Leigh
11-May-2013, 08:40
The dark bands are in the part of the negative that would be at the top when the photo was taken.
That's pretty severe.

One way to check is to leave your darkcloth over the camera throughout the exposure sequence, so it's shielding the film holder. I clip mine to the camera with a couple of clothes pins. Then it can drape over the back and not come loose.

Take a couple of shots in one holder with the darkcloth in place, then another pair with the darkcloth removed.

Make sure your holders are fully seated in the camera. There's a little ridge on the holder just above the opening. That should seat in the camera back.

As to your exposure...
Without knowing what film you're using, I can't comment on whether or not it's accurate.
Use the "sunny 16" rule... f/16 with a shutter speed that's the reciprocal of the film speed for normal daylight scenes.

- Leigh

John Olsen
11-May-2013, 08:55
Not a darkroom problem since there are relatively less-exposed edges on the film.

Two different holders would seem to rule out the holders. Except if they were both warped with age or misuse they could fit in the back badly. Or maybe B&Js require special holders?

Or they could both have no felt left in the slide entrance. Try a shot with dark cloth held over the slide position as you pull the slide and shoot?

But most likely there's an ugly crack in the bellows. Get a flashlight and a small hand mirror and start testing.

How disappointing, good luck.

John

mandoman7
11-May-2013, 13:53
How old are your holders? The felt that's inside can wear out and light will get in if you leave the dark slide out for a while. Light can also get in if you're not careful during removal or insertion of the slide, and pull the holder away form its seal. You're leaks are coming from that area, though, rather than bellows leaks, where you'll see streaks that are a little more away from the film edges.

jackbaty
11-May-2013, 15:40
Thank you all for the comments. I inspected the bellows as suggested with a flashlight and didn't see any light leaks. Then I thought I'd look for leaks when the film holder was inserted. Turns out I wasn't inserting the holder all the way! How I didn't notice that before is beyond me, but that was definitely the problem. The attached image is proof. Taken handheld and JOBO processed (HP5+ in Xtol).

It's not art, but it's exciting!

Thanks again.

94893

Leigh
11-May-2013, 22:51
Great news. Congrats. (nice dogs)

- Leigh

cepwin
11-May-2013, 22:58
Super!!! Lovely dogs!

swittmann
11-May-2013, 23:19
Jack, I made exactly the same mistake when I started with LF... lol! Lesson learned ;)

Have fun!
Sandra

John Olsen
12-May-2013, 18:25
OK, now on to the other 1000 small problems you can encounter. Thanks for letting us know of the resolution on this one. It's a good reminder for all of us (or at least me).

jackbaty
13-May-2013, 05:32
OK, now on to the other 1000 small problems you can encounter.

I'm beginning to understand that. With large format, the path to a successful image is long and littered with any number of ways to fail. If it were easy it wouldn't be nearly as fun! :)