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  1. #1

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    Tolerant Color Neg Films / Films for Pushing

    Two part question:

    1. There is an old thread I found on here that discussed how the new Portra 400 is very sensitive to magenta shadows if the processing is not just exactly right. I found this to be true, as I developed 7 rolls of it plus one roll of Fuji 400H in the same tank a couple of weeks ago using my Trebla chems. Shadows on the Portra rolls have a strong magenta cast, but only in the shadows. The Fuji roll in the same tank did not have this problem. So I got to thinking, what are the most robust and forgiving films for small time/temp deviations/mistakes in home processing?

    2. Pushing! What films (any speed) yield the most stable color when extending development? I'd like to avoid any weird color effects, and just get a higher contrast neg. Other contrast-increasing methods welcome here too.

    Thanks!

  2. #2
    AgX
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    As a historic side-note: Once there had been films specially designed for push-processing (Ferrania, Fuji, Kodak).

  3. #3
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    It is best to over or underexpose a negative film. Pushing or pulling is not the best answer. And, the slower speed films are best for over or under exposing. I have exposed Portra 160 at 200 and 400 with good results and I've exposed Portra 400 at 800 with good results, all with no push.

    I've posted the color chart exposures here.

    For the best results, exposue Portra 160 at 100 and 400 at 320 though.

    PE

  4. #4

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    But that won't raise contrast. I'm not really concerned about gaining speed, just contrast.

  5. #5
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    Portra 400 then, pushed 1 stop will give plenty of contrast, but not much latitude. In fact, you can push it 2 stops and still get usable results. I think that ISO 1600 is enough, but it will be grainy and very touchy to use.

    PE

  6. #6

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    Quote Originally Posted by Photo Engineer View Post
    Portra 400 then, pushed 1 stop will give plenty of contrast, but not much latitude. In fact, you can push it 2 stops and still get usable results. I think that ISO 1600 is enough, but it will be grainy and very touchy to use.

    PE
    Thanks. Should I expect the color to be corrupted by this? An even cast I can correct for, but if the color cast changes with density (as I've experienced), then I'm stuck with a Photoshop nightmare and I lose the ability to make an optical print in the future.

    PE, a few years back you recommended sodium sulfite to me to LOWER contrast and saturation in either C41 or RA4, and it worked pretty well. Is there a similar magic trick to do the opposite and raise contrast chemically, without screwing up the color?

  7. #7
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    It is very very difficult with any color film to increase contrast without messing the color quality. You get crossover. Even the Sulfite trick causes some crossover. I can suggest some methods such as adding more CD4 and adjusting the pH back to normal, or just raising the pH with base. But, sadly, these do cause problems.

    The best way to do what you want is a simple push, and even that is mediocre IMHO. Remember, I used to coat these films so I know what the problems are in every detail.

    Hey, if you can get some Gold, or the consumer equivalent, that has higher contrast than Portra. It pushes no better but starts higher by about 0.01 in contrast (or thereabouts). It is made for the consumer market with higher contrast to give the pix a higher snap and to compensate for the flare of non-professional systems.

    Try it, you might like it.

    PE

  8. #8

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    Thanks. I've shot quite a bit of Gold 400 and the Fuji equivalent, but it's been a while, and I don't think I tried pushing them. I still have a mini-fridge full of Gold, think. I'll have to play around. The Portra seems really sensitive and I'd like to standardize on something pretty flexible. I'm looking for my color equivalent of Tri-X!

  9. #9

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    My guess (and it's only a guess) is that the amateur films - Kodak Gold and its Fuji equivalent) Are probably more tolerant to mis-processing than the professional films. But it may not be by much. The amateur films are designed for a certain amount of environmental abuse (high storage temperature, long latent image storage, and the like) and for processing in many, many small labs which may or may not use the quality control tools correctly. A lot of attention was paid to making these films work right under just about any circumstances. With the professional films the attitude has been that the user is responsible for doing things right.

  10. #10

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    Porta was deliberately engineered for better storage and latent image characteristics for travel/temp
    issues than older pro color neg films. I read an official announcement regarding that. But I sure wouldn't want to tamper with the processing.

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