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  1. #1

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    Tri-x 400 at 25,600

    I've got some tri-x to play with, and I've got Adox APH 09, I'm hoping to use this as a rodinal equivalent and push this film through semi-stand development. The MasDev chart says 51 minutes with 30 seconds agitation and then agitation every five minutes. That is for rodinal 1+50, anyone have an idea where I should start?

  2. #2
    2F/2F's Avatar
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    Hi,

    Uprating a film doesn't mean you are changing it's sensitivity to light (film speed). It just means you are lying to your light meter and saying that you have a faster film, when you really do not. Thus, when you uprate, all you are doing is underexposing the film by using an EI that does not match the ISO film speed.

    So, Tri-X at 25,000 is SIX stops underexposed (25K, 12.5K, 6.4K, 3.2K, 1.6K, 800, 400). Think about what that means in terms of tonality. Everything shifts down 6 notches on a gray scale. This means that anything not distinctly brighter than middle toned in the composition (above Zone VI) will be rendered without any detail, texture, or even any tone. I.e. everything will be pitch black except for things that were quite bright at the scene of exposure. And there is absolutely nothing you can do in printing to put texture or detail back there. It also means that the brightest whites in the composition will be exposed as middle gray at best. Therefore, anything between middle gray and the brightest whites will be dark shades of gray.

    Pushing your film can only do so much. It is limited by what is placed there with exposure in the first place. Pushing most affects the areas that have received the most exposure, and vice versa. If middle gray is the highest anything was placed with exposure, that can only be raised so much by pushing. And Zones 0 - IV, where most of the printable area of your picture will end up falling, cannot be pushed all that much.

    BTW, ISO 25,600 is a digital-only number. ISO never specified details for speeds over 10,000, I believe, but something they published at one point suggested that if they had, they would have gone to 12,500 as the next number, not 12,800. So, I think EI 25,000 is the best way to refer to it when speaking of film.

    At any rate, stand development is exactly what you don't want in this situation. You want aggressive agitation in a strong, speed-supporting developer. Diafine is great at supporting the low tones, but won't do much to punch up the high end. I might use Microphen. Or, I might use Diafine followed by Microphen and see what happens!
    2F/2F

    "Truth and love are my law and worship. Form and conscience are my manifestation and guide. Nature and peace are my shelter and companions. Order is my attitude. Beauty and perfection are my attack."

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  3. #3
    polyglot's Avatar
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    Respectfully 2F, no. Pushing does actually give a speed increase and (semi-)stand development can give a significant true speed increase. And the contrast increase from pushing does mean that highlights will still print as highlights; it's not like you're just shoving the tonal scale down into darkness, it gets stretched.

    If you (semi-)stand develop in a compensating developer like Rodinal, you can actually get a significant increase in sensitivity of your film without an unmanageable increase in contrast because development continues in the shadows while development pauses in the highlights. Asking for 25,600 is too much though, even for 400TX; with that optimistic of a push, you really will end up with only highlights at most.

    If you've got film to play with, try it at 1600 and 3200 first. Those sorts of speeds are achievable with care whereas 25,600 is just too optimistic for this film, especially if you've not done some experimenting first.

    As a constructive suggestion, I would go for Rodinal 1+100 (at least 600mL to ensure that there is at least 6mL of concentrate per roll; 300mL if it's just half a roll) for one hour. 30s of agitation at the start then three or four inversions once every five or ten minutes. Do a test with just a few frames and use the following corrective procedure:
    - not enough contrast / highlight density => more frequent agitation
    - too much contrast => less frequent agitation
    - not enough shadow detail => longer time
    - thick negative => less time
    - vertical streaks (bromide drag) => shorter gaps between agitation

    In theory at least you can do agitation for 30s then once again at 1 minute and leave the thing to just sit there for two hours. If you're lucky, you will get an excellent result but you run the risk of bromide drag ruining the negatives; it's evident as dense streaks down the negative starting at the highlights. If you're not getting bromide drag no matter how long you wait between agitations, you can take that full stand-development approach. If you are getting bromide drag then your only choice is to have more-frequent agitations, which means more contrast. The increase in contrast will often be the limiting factor to the speed you can achieve.

    One drawback to (semi-)stand is that the compensation effect can make the highlights a lot less sparkly than with normal development.

  4. #4

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    Here's TriX at ISO 12K. Rodinal 1:100, semi stand for 2 hours. After initial inversion, give it a few swirls and maybe an inversion every 30 min.


  5. #5
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    You can effectively change a films character by the development/chemistry you use. Each film will be different and create its own curve depending on what you throw at it. Nothing is set in stone. Typically; longer development times do better for this kind of push.



    Quote Originally Posted by Joe O'Brien View Post
    I've got some tri-x to play with, and I've got Adox APH 09, I'm hoping to use this as a rodinal equivalent and push this film through semi-stand development. The MasDev chart says 51 minutes with 30 seconds agitation and then agitation every five minutes. That is for rodinal 1+50, anyone have an idea where I should start?

  6. #6

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    No amount of development or development method can create shadow detail where none exists. If you do not mind empty shadows then you may be happy pushing film. The sample photograph illustrates this point nicely. High sulfite, low alkalinity phenidone developers like Xtol and Microphen can produce a modest increase in film speed of about 2/3 of a stop. They do this by more fully developing the activated sites in the emulsion. But there is a limit as to what can be done. Sorry but 2F/2F is right, you cannot change the laws of physics.
    Last edited by Gerald C Koch; 07-03-2011 at 10:49 PM. Click to view previous post history.
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  7. #7

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    Thanks to everyone who's contributed. Could I do anything with pre-exposure? Say I gave the film three or four stops of exposure and then shot my final image, would this achieve similar results as when done to paper? Would I be able to capture shadows with less exposure of the scene? I read about this in Adams' "The Negative", though it was only discussed as a one stop increase there, if I recall.

  8. #8

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    There are two ways of increasing the sensitivity of film. There is hypersensitization which is done before and latensification which is done after exposure. According to Glafkides these methods can increase the film speed by 100% t0 300%. However, he goes on to say; "The various methods of intensification are usually critical operations to perform in praactice, since the results will vary not only with the type of emulsion, but also between two identical operations on the same emulsion." I think this sums up why people seldom resort to this type of intensification.

    Probably the easiest method is to hypersensitize the film by exposing it to a dark green safelight. To be effective the light must be of low intensity and long duration. The article I read many years ago described using a Kodak Brownie safelight 7.5 watts with the light output reduced by a half to a quarter at 10 feet. You would have to experiment as to the distance and the time. IIRC, the time was in the range of 10 to 20 minutes. The film must be exposed within a few hours as the effect wears off rapidly.
    Last edited by Gerald C Koch; 07-04-2011 at 12:28 AM. Click to view previous post history.
    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

  9. #9
    markbarendt's Avatar
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    Quote Originally Posted by Joe O'Brien View Post
    Thanks to everyone who's contributed. Could I do anything with pre-exposure? Say I gave the film three or four stops of exposure and then shot my final image, would this achieve similar results as when done to paper? Would I be able to capture shadows with less exposure of the scene? I read about this in Adams' "The Negative", though it was only discussed as a one stop increase there, if I recall.
    The pre-exposure idea works at getting more detail but in the field with roll film I don't know how practical it really is.

    One thing to remember here is that you not just dancing with the film, your dancing with the paper too.

    Steeper, pushed/plus development, film curves intrinsically print fewer zones on a specific paper grade than normal, flatter, curves.

    Changing paper grades can get you a print with a larger range of detail from the film, but as Gerald says, that detail has to exist and the low threshold is controlled by film exposure.

    A second thing to remember is that if you need EI 25000 the lighting probably sucks. Artificial lighting, done well, could probably improve the shot more.
    Mark Barendt, Ignacio, CO

    "We do not see things the way they are. We see things the way we are." Anaïs Nin

  10. #10
    Athiril's Avatar
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    I did 51,200 shot, using a push to 6400. The negs were thin and grain is massive, and exaggerated due to the need of increased contrast to get blacks to black and whites to white from the neg (whether you scan or print).

    Rodinal 1+100, 30 secs initial agitation. 2 hour semi-stand, 2 gentle inversions at 40 min then at 80 min.

    25600 will be thin as well. For Rodinal? I'd probably do a pair of 1+100 2 hour semi-stands, not sure where to begin with 1+50, have gotten terrible results standing/semi-standing with 1+50 before for long periods of time.


    The is 6x7cm, Tri-X @ 51,200 push to 6400 (thin negs). There is 2.5 stops of dynamic range. The water reflection has detail, but I threw it out via contrast instead of burning it in. More dynamic range if you count into the highlights.. but that's a fruitless exercise, so I do not count that.

    Everything has detectable contrast (detail), apart from the black bushes to the right and black landscape area.

    So you're likely to get 3-3.5 stops of dynamic range if developed well for 25,600, not counting extension into the highlights.

    My feeling is you will get different results on different rolls of Tri-X of different unexpired ages.


    However the 2 hour semi-stand is useful for just flogging out some Tri-X @ 1600-6400 to get usable results over a large push range.

    Tri-X 51200 Test #1, Beach Night by athiril, on Flickr
    Last edited by Athiril; 07-04-2011 at 08:52 AM. Click to view previous post history.

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