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  1. #1
    David Lyga's Avatar
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    warning about color film fog

    I have some old Fuji Super G+ 100 film that I had bought in bulk rolls years ago from Freestyle Photo. It was only $10 per 100 ft and I bought dozens and keep it in my freezer. It 'expired' in 1998.

    The speed is still a full 100 and there is no fog. But... the sensitivity of this film to low Kelvin light (red, yellow, etc) is astounding. It took me a full year to discover just what was wrong with all the ugly green base I was getting all too often. To quantify this distress I offer the following. I really do not even expect all to believe me it is so sensational.

    I have a surge protector under my work desk that has a red light on it. Certainly, if you bring an unexposed color film right next to it you will get fog. We all know that. But I tried something else to confirm my suspicions: I pulled an inch of the film from the cassette and held it six feet from the light for ten seconds. First, let me say that, at six feet from this red light you cannot see any white at all from a piece of copy paper, even after your eyes get accustomed to the 'darkness' for 15 minutes. It is THAT dark an environment.

    I then, in TOTAL darkness pulled out another few inches and made one exposure in my camera and processed the few inches of film. I was amazed to find a THICK green cast over the part that was hand held six feet from the red light. What the eye cannot see is 'seen' by this film. The green cast stopped abruptly at the point where the film had still been in the cassette. I also did another experiment: in TOTAL darkness I pulled a few inches of this film from the cassette and placed the cassette into a new paper safe in perfect condition. I kept this paper safe in bright light for one week. After that time, again in TOTAL darkness, I pulled a couple inches of additional film from the cassette and made an exposure in my camera. After processing the film, again, at that point where I pulled additional film and made the camera exposure, there was a change: the camera exposure was perfect, orange base and picture, but the first 'exposure' where I left the blank film in the paper safe, had a light green cast throughout, ending abruptly where the cassette felt started. Photons had gotten INTO the paper safe. Only slightly, after a full week of bright light, but they had gotten IN!!!

    Those used to using only B&W film be forewarned: color film, maybe only this special Fuji one in particular, has a hair like trigger that causes the couplers to react. Honestly, NO B&W film was ever THIS sensitive, even TMZ or DELTA 3200. It is truly amazing and took me one year to zero onto this.

    I have tried this with various Kodak color films and they are not THIS sensitive. - David Lyga
    Last edited by David Lyga; 12-21-2012 at 03:08 PM. Click to view previous post history.

  2. #2
    AgX
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    Relating to your first experiment: Film accumulates light, the eye does not. One of the many diffrences.

    Concerning couplers: they are not involved in exposure (except for the filter-characteristic of coloured couplers).

  3. #3
    Photo Engineer's Avatar
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    Yes, it accumulates light and the result you get in the first experiment is expected.

    As for the second, it is a paper safe and paper is many times slower than film and is not sensitive to red light. So, there very well may be a light leak through the safe that is OK for paper but bad for film.

    PE

  4. #4
    BetterSense's Avatar
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    Is it possible that the film is fogging due to atmospheric exposure (humidity/oxygen) rather than light?

    It's 14 years expired, after all. I've bought boxes of expired sheet film in the past, and the opened sheets were fogged with age, but the ones still sealed in the packets werefine.
    f/22 and be there.

  5. #5
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    Probably not at this time.

    PE

  6. #6
    David Lyga's Avatar
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    I have to say, PE, that that is rather fascinating what you just said about the safe being 'safe for paper' but not necessarily safe for color film. Indeed, one wonders for just how long the paper safe is 'safe for paper' since you confirm that, indeed, some theoretically tiny amount of 'light' actually might get into the safe and, of course, can accumulate. Boy, is B&W a different way of thinking about things such as this! Aside from the fact that the paper has no, or low, sensitivity to red, one really wonders if any light accumulates to fog, albeit slightly, eventually even the paper. I am so tied to 'if you cannot see it, it does not exist' and this is just plain wrong on my part.

    Ignorantly, I had thought that the paper safe was safe, period. There are qualifiers which necessarily must go along with that truism. I have to admit, again, that this experiment has opened my eyes a lot, even after 48 years in the darkroom. And to hear that said by someone like yourself and for me to witness the actual veracity of that fact is compelling. Sorry for the emotion here but that is revelatory. Not so often is that fact experienced but it does exist.

    What if I made a statement such as this? Age fog is caused by photons entering and passing through light-tight packaging. Even the most dense, 'light-tight' material will allow a few photons to cross its threshhold. This accumulates slowly, very slowly, but it happens and results in slight base density, perhaps only after several years' time.

    And BetterSense: that finding on your part is interesting. I have no answer for you but I assume that both films, the one sealed and the one not sealed, were kept in the same package, so that there is no chance of other factors entering into the equation. Or I wonder if light had a 'better' opportunity to enter onto the unsealed film. - David Lyga
    Last edited by David Lyga; 12-22-2012 at 02:27 PM. Click to view previous post history.

  7. #7
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    David;

    Imagine a paper safe made from red plastic. Paper is not sensitive to red light. Therefore, the safe is 100% light tight as far as paper is concerned but it will fog film.

    Of course there are a lot of alternative scenarios for your observation.

    PE

  8. #8
    AgX
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    Colour films typically reach more into the red than b&w films.

  9. #9
    BetterSense's Avatar
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    I have a Canon FT 35mm camera would randomly leave red streaks on color film. I shot almost exclusively Fuji Superia at the time. I've been using the same camera for B&W and I've never notice a light leak.

    Come to think of it, every time I've had a light leak on a camera with color film loaded, it always manifested as red streaks.
    f/22 and be there.

  10. #10
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    If you have red streaks on a piece of color negative film, it was exposed to green light. If the prints have red streaks, then it was red light or daylight.

    PE

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