Light Leak?

[revdocjim]

I'm wondering whether my film holder has a light leak. I got this result and the pinkish cloud like stuff in the top right corner looks like something other than clouds the more I look at it.

This was taken with my Wista 45N, Nikkor-W 180mm f/5.6 on Velvia 100F. I have 5 film holders and don't know which one this sheet was in, but I'm wondering if I have a leak. What makes me especially suspicious is that the pink coloring extends beyond the border of the photo and into the black perimeter on the developed film.

I'm completely new to LF photography so I don't even know how to go about inspecting my film holders for light leaks.

All comments, opinions & pointers appreciated!:)

http://www.pbase.com/revdocjim/image/132942963/original.jpg

[Professional]

I feel this is not a light leak, at the end you can remove that pink easily, but you have to shoot more and see if you will see same problem or worse later, i can't tell if that is a light leak issue or not, but maybe another members with more experiences will tell you.

Nice shot by the way!

[Ken Lee]

When pulling out the dark slide - and when returning it - it's a good idea to make sure that the camera back is firmly holding the film holder against the camera.

If the film holder comes away from the camera by a fraction of an inch, a gap can appear, and we will see a small light leak in the corner of the photo. It's not coming through the bellows. It's coming from behind the camera.

A good counter-measure, is to hold the camera back shut with one hand, whenever removing or replacing the dark slide with the other hand.

[Douglas Henderson]

It doesn't really look like a light leak--it isn't diffuse enough. I think you caught the edge of a high, icy cloud. It almost looks like the "cloud" is beginning to become reflected in the lower right ripples in the water. The magenta tone of the white area matches the magenta tone evident over the whole image.

If it is a leak, it is coming from the lower left corner of your cut film holder when mounted in your camera--an area least likely to leak light.

Nice photo. Maybe you could note which film holder is used for each shot for a time sufficient to settle any light leak issues for you. I've had some pesky, intermittent leaks when shooting fast 5x7 film--which I attributed to sun shining directly in the dark slide slot.

[Jerry Bodine]

If the problem repeats with future exposures, inspect the light trap material on the camera back. It may be starting to separate from the back and not allow the holder to seat firmly. Happened to me when I was just beginning LF, because I was not being gentle when inserting the holder into the camera. Live and learn.

[Dave Hally]

"What makes me especially suspicious is that the pink coloring extends beyond the border of the photo and into the black perimeter on the film."

If it is beyond the border, under the lip of the holder, then it is most likely exposed after ( or possibly before) the film was loaded and unloaded. Unless that corner of the film was stuck above the lip, in which case you might see a " crimp" and not the shadow of the lip. Show us a scan of the full corner of that film, and we may be able to give a better opinion.
Dave

[al olson]

. . .
What makes me especially suspicious is that the pink coloring extends beyond the border of the photo and into the black perimeter on the developed film.
. . .


revdocjim,

I sorta agree with Douglas on this, except that you say the coloring extends into the rebate. Now at this point the film is covered by the flap, so as long as the flap is pressed down onto the film there should be no exposure of the rebate. I can't think of any way for the light to expose that area unless the tape has become frayed along the edge or unless it were somehow exposed by handling.



. . .
I'm completely new to LF photography so I don't even know how to go about inspecting my film holders for light leaks.

All comments, opinions & pointers appreciated!:)
. . .

With regard to testing your holders: I have bought a goodly number of used holders and from time to time I would be infected with a light leak (on the best shot, of course). I had used a file to cut notch codes into the flaps of all of the holders to identify the culprits.

The same holder did not always exhibit a leak, depending on circumstances such as bright sunny day, how long they were in the camera with the dark slide pulled, etc., so I never knew for certain if the leaks were caused by the holder, the camera, or by my mishandling.

I finally decided that I was not going to gamble with the holders any more. I penciled a number on each holder. Then I cut paper negatives from enlarging paper. (A paper cutter is handy here because the width has to be about 1/16" narrower than a nominal 4x5.) ... And loaded the holders.

Next I laid them out on a table and, using my Vivitar flash manually, flashed each one first from the top and then from the bottom, turned them over and repeated the procedure.

Leakage problems are frequently caused by a faulty light trap. So I set my camera on the tripod, inserted the holder and removed the slide. Then I placed the flash against the light trap and flashed it twice. I did this for each side of each holder.

Finally I went to the darkroom and developed the paper negatives, two at a time from each holder. When I removed the paper from the holder, I wrote the number of the holder on the back with pencil before placing it in the developer.

I identified six holders that had defective light traps and have removed them from my supply. I also found one holder that had a piece broken from the edge of the flap.

I hope this is useful.

[revdocjim]

Here is a low res scan of the entire sheet.

http://www.pbase.com/revdocjim/image/132964229/original.jpg

[Jack Dahlgren]

That is a light leak or developer problem. It is definitely not a cloud. From that pattern I'm not sure if it was during exposure or some other time while it was being handled. It looks almost like the effects of static electricity.

[revdocjim]

I don't know if it helps at all but I found something interesting when I looked closely at the scan of this portion of the sheet. Dust specs generally show up as black spots. But in this part of the exposure there are numerous white spots and they have distinct shadows. What is especially strange to me is that the direction of the shadows indicate a light source opposite of where one would expect the light leak to have occurred. The light leak appears to have come from the right side. The shadows on the white specs indicate a light source coming from the left... FWIW, this corner is the only area where I found those white specs, and the don't come off with a blower so I'm inclined to think they are part of the exposure... Which leaves me completely confused.

Any thoughts?

http://www.pbase.com/revdocjim/image/132966384/original.jpg

[Ken Lee]

Chemical stains during handling/processing ?

The stain is where a clip holds the film.

Who develops your film ?

[revdocjim]

This film was sent to the Fuji lab and I've had lots and lots of 120 and 135 film developed by them without problem, and several sheets of 4x5. But this is the first time I've seen anything like this.

[al olson]

revdocjim,

The larger bits appear to be lint, possibly from gloves that are not clean. If that is the case, so much for handling by the edges. I am assuming that these are on the emulsion side.

The fact that they are throwing shadows would indicate that they are not embedded in the emulsion, but instead lying on top, although some of the fibers may be sticking to the emulsion.

Try taking a PEC wipe with a little PEC cleaner on it and gently wipe over this area several times to see if they go away or are displaced.

It is not impossible that this area could be exposed by an oblique ray of light coming from the left. If this happened between exposure and development, you could be getting an image of the lint which would glow white and throw the shadow.

If this is the case, then the question would be what source of light would be in the darkroom that would expose such a small area of the negative. Was the film handled near something luminous such as a watch or glow tape or timer?

I do not conceive that the shadow would have been cast by your scanner.

[Bryan Lemasters]

I don't know if it helps at all but I found something interesting when I looked closely at the scan of this portion of the sheet. Dust specs generally show up as black spots. But in this part of the exposure there are numerous white spots and they have distinct shadows. What is especially strange to me is that the direction of the shadows indicate a light source opposite of where one would expect the light leak to have occurred. The light leak appears to have come from the right side. The shadows on the white specs indicate a light source coming from the left... FWIW, this corner is the only area where I found those white specs, and the don't come off with a blower so I'm inclined to think they are part of the exposure... Which leaves me completely confused.

Any thoughts?

http://www.pbase.com/revdocjim/image/132966384/original.jpg

Until I saw the shadows cast by the lint (?) my initial thoughts were a light leak at the loading hinge tape, but now.............

Looking at the direction of the shadows, the light source had to have come from the right, and slightly lower than the camera. In looking at the image the sunlight is behind and to the left of the camera (judging by shadow areas near the trees at lower left of the image). It would seem unlikely that a light leak through the light trap of the film holder would travel that far before striking the film, but that is the only conclusion that I can reach. A "hot spot" of sunlight might have been reflected from something to the right of the camera.

It would seem to me that an accidental light exposure during handling or processing should have increased the values in the shadow areas of the lint just a bit.

My 2 cents.