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  1. #11
    Rudeofus's Avatar
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    Quote Originally Posted by Athiril View Post
    H2O2 and Mercury hypering improved Provia 400X pushed to 1600 results for one user.
    Believe me, I am a die hard analog user, but when it comes to use of Mercury vs. a d*gital camera I'd go for the latter, regardless of whether Mercury provides a measurable benefit or not.
    Quote Originally Posted by Athiril View Post
    What methods have you tried with which modern films and found no effect?
    I've not done any experiments myself, and from reading countless postings, books and other resources about these procedures I see little reason to do so. Tell me a working recipe that boosts the speed of Delta 3200, Provia 400X or Portra 400 without the use of extremely dangerous chemicals and I'm all over it.
    Trying to be the best of whatever I am, even if what I am is no good.

  2. #12

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    What do you mean, "used"? ..You mean, fixed?

  3. #13

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    My 'bible', "Dictionary of Photography" (19th Edition, 1961, Iliffe Books Ltd., London) Sowerby, A.L.M. (ed), pp 380-381 gives the following formula for hypersensitising film:

    Alcohol (90 per cent) - 8 parts
    Ammonia (0.880) - 1 part
    Water to - 32 parts

    "Immerse panchromatic materials for about five minutes. Dry as quickly as possible in absolute darkness and use within a few hours. The speed can often be doubled (increased by 3 degrees B.S.) in this way, but there is a distinct tendency to fog."

    It also mentions using sulphur dioxide as an "effective, safe and reliable" method of hypersensitising. Exposed film is loaded into a sprial, then placed into a lightproof container such as a bisuit tim over an open vessel half-filled with a mixture in equal parts of sodium sulphite and glacial acetic acid. Develop normally after 24 hours exposure to the sulphur dioxide. The book reports a doubling of speed or a little more.

    Cheers,
    kevs
    testing...

  4. #14

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    I once mistakenly shot a roll of Fuji Neopan SS (100 speed) at 1600 thinking it was a roll of Fuji Neopan 1600 at a wedding. It was pretty much a 'Hail-Mary' attempt, but I did the Anchell-Troop recommended and the negs turned out very well, a bit grainy but I was amazed that not only did it work at all but I actually liked the look. For the effort I wouldn't recommend it, but it sure saved my butt that time.

  5. #15

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    Quote Originally Posted by Gerald C Koch View Post
    The Anchell books contain quite a few errors so read them cum grano salus.

    You use a SS two reel tank with a small amount of 3% hydrogen peroxide in the bottom. An empty reel actrs as a spacer between the film and the peroxide. The film is left for a number of minutes which must be determined by trial and error for each film used. The film must be used shortly after treatment and cannot be stored as it reverts to its normal unsensitized state quickly.
    If I read Anchell correct the H2O2 treadment is done after development, before fixing and not before exposure like some of the other method he covers.
    Best regards
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  6. #16
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    Quote Originally Posted by Nicholas Lindan View Post
    Hypersensitization doesn't increase speed. It decreases reciprocity failure.

    It also works best with slow films, like Tech Pan. Hypered Tech Pan is one of the fastest films when it comes to 6 hour exposures. For TP and astro films (TP was originally 'solar flare patrol film' - hence the extended red sensitivity for imaging the hydrogen line, making it beloved of amateur astronomers) there is some modest across the board speed increase, but nothing to write home about - I ordered some hydrogen hypered TP once, maybe it was ASA 40 rather than 25 for normal use.

    Hypersensitization won't do anything for you if you are trying to get more speed out of Tri-X.
    Yes and no.

    This is true of the gas hypering that amateur astronomers used pre-digital. H2O2 vapor is a different thing, and with different results. It's been literally 30 or more years and I sure don't remember the details but I came across a method for this back when I was in high school and tried it, getting a quite workable EI 6400 out of Tri-X.

  7. #17
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    Quote Originally Posted by Soeren View Post
    If I read Anchell correct the H2O2 treadment is done after development, before fixing and not before exposure like some of the other method he covers.
    Best regards
    Another difference from gas hypering for astrophotography - whatever it was I did back then was definitely in the development phase, nothing pre-exposure. I recall the article (a friend gave me a photocopy) was called "kick in the pants developing."

  8. #18

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    Quote Originally Posted by Soeren View Post
    If I read Anchell correct the H2O2 treadment is done after development, before fixing and not before exposure like some of the other method he covers.
    Best regards
    There is a big difference between hypersensitization and latensification. Hypersensitizing a film is done before and latensification is done after exposure. Some authors either equate or confuse the two. The mechanism for the two processes is different. However, the same chemicals hydrogen peroxide, mercury, sulfur dioxide, etc may be involved. For the average photographer the processes are a curiousity and more bother than it is worth. This is why only astronomers use these technoques because they must.

    For those who insist on trying hypersenitization the easiest method is exposure to a very dim green light for an extended period of time. The method most often described is the use of a Kodak Brownie safelight with the green cup. A 7 watt bulb is used and half of the cup is covered with black tape. IIRC, the film is exposed at a distance of 8 to 10 feet for a period of several minutes. Afterwards the film is respooled for use. As I mentioned before every film is different and the method must be tweeked for each film.
    Last edited by Gerald C Koch; 02-20-2013 at 11:55 AM. Click to view previous post history.
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  9. #19

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    Quote Originally Posted by Gerald C Koch View Post
    There is a big difference between hypersensitization and latensification. Hypersensitizing a film is done before and latensification is done after exposure. Some authors either equate or confuse the two. The mechanism for the two processes is different. However, the same chemicals hydrogen peroxide, mercury, sulfur dioxide, etc may be involved. For the average photographer the processes are a curiousity and more bother than it is worth. This is why only astronomers use these technoques because they must.

    For those who insist on trying hypersenitization the easiest method is exposure to a very dim green light for an extended period of time. The method most often described is the use of a Kodak Brownie safelight with the green cup. A 7 watt bulb is used and half of the cup is covered with black tape. IIRC, the film is exposed at a distance of 8 to 10 feet for a period of several minutes. Afterwards the film is respooled for use. As I mentioned before every film is different and the method must be tweeked for each film.
    Ok but that doesn't really matter. the OPQ was about H2O2 steaming which is done after development, before fixing and, as you would put it, is a latensification method.
    Best regards
    Last edited by Soeren; 02-21-2013 at 02:11 AM. Click to view previous post history.
    Send from my Electronic Data Management Device using TWOFingerTexting

    Technology distinquishable from magic is insufficiently developed

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  10. #20

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    Quote Originally Posted by Soeren View Post
    Ok but that doesn't really matter. the OPQ was about H2O2 steaming which is done after development, before fixing and, as you would put it, is a latensification method.
    Best regards
    My crystal ball is in the pawn shop and so I could only base my comments on what the OP asked. He didn't specify whether the process was to be done before or after exposure. My copy of Anchell is currently being used to prop up the short leg of my kitchen table.
    A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.

    ~Antoine de Saint-Exupery

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