From: Shannon Stoney (sstoney@pdq.net)
Date: 03/01/03-12:47:40 PM Z
>I am sending this message again because the previous one was sent
>from my time travels in the early years of the 20th century and I
>was not sure that the appropriate network servers were available on
>the lines then in use to relay the message to you in your real time.
I hope you traveled in a De Lorian. Was there any warping in the
space/time continuum? Did you bring back any whales?
--shannon
>
>Sandy
>
>
>
>
>
>Shannon,
>
>There are dozens of things that can result in fogging. Since the
>edges of your film are clear I think it is safe to say that the
>fogging is taking place in *the holder when it is in the camera and
>the dark slide is removed.* The clear edges suggest that the fogging
>is not taking place in the film box, and it is probably not the
>result of just carrying the film around outside in the holder. Since
>the problem also appears to be happening with more than one holder I
>would suggest that the light leak is probably not being caused by a
>failure of the light baffle in the holders, since it is highly
>unlikely that all of your holders are bad.
>
>The most likely reasons for the fogging, in my opinion, and in
>descending order of probability based on your description, are:
>
>1. The film holder is not seating correctly in the camera. The
>light-baffle mechanism for most film holders is that there is a
>ridge on the holder that drops into a groove on the camera back when
>the holder is fully inserted into the camera. If for some reason the
>ridge does not drop into the groove there will almost certainly be a
>light leak, and it could be anywhere on the film. Check for this by
>inserting a film holder in the camera but do not remove the dark
>slide. Then, in total darkness, put a light in the camera from the
>front and then baffle off the opening. Now look all around the edge
>of the back where the film holders meets the back, with very close
>attention to leading edge on the right side where the baffle is
>located.
>
>2. The back of the camera or of the holder is warped.
>
>3. There is a pinhole somewhere in the bellows. It takes only a very
>small pinhole to cause a lot of fog, and sometimes, for example when
>the pinhole is close to the crease of the bellows, it will only
>manifest itself when the bellows is fully extended, so be sure to
>test the bellows for light leaks with the bellows racked out all the
>way.
>
>4. Light leak where the frame of the bellows attaches to the camera,
>either at front or rear.
>
>5. Light leak where the lens board attaches to the camera, or where
>the lens is fitted to the board.
>
>6. Light from the holder itself. The most likely cause is a bad
>baffle. To check remove the dark slides and look back up through the
>baffle from the bottom of the holder, with the baffle held against a
>strong light.
>
>Good luck, but don't leave home again without solving this problem.
>There is nothing more frustrating than to fog a lot of large format
>film when a short inspection could have detected the problem.
>
>Sandy
>
>
>
>>I have been processing some 8x10 negatives that I made in December
>>and January on a trip to TN, and a lot of the images have fogging
>>around the bottom of the image, the bottom sides I should say.
>>Sometimes I think this is caused by the film holder not being
>>seated correctly in the camera back, so that the top of it
>>protrudes a little. I need to be more careful about that. But,
>>how can I test to see if any of the film holders are leaking?
>>
>>Also, I never seemed to have this problem with the 4x5 camera. The
>>8x10 seems to have a tighter spring on the back so that it's harder
>>to push the film holder all the way down. Is this just because the
>>film holders are heavier so the spring has to be tighter? Also,
>>the fogging begins about 1/4" into the image. The very edges of
>>the image are ok.
>>
>>--shannon
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