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  1. #11
    georgegrosu's Avatar
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    epatsellis -
    I'd love to see this done with control strips and densitometer measurements.
    And I would like to see curves sensitometrice.
    PROCESS MONITORING AND TROUBLESHOOTING (Manuals: Z-131) is designed as a guide for color negative process – photo.
    For color negative film process - cinematography there is a similar material which is called Processing KODAK Motion Picture Films, Module 8. Effects of Mechanical & Chemical Variations in Process ECN-2.
    http://motion.kodak.com/motion/uploadedFiles/h24_08.pdf Figure 8-1 Effects of Time Variations—5213, 5254, and 5242 Films in Process ECN-2 Developer and Figure 8-2 Effects of Temperature Variations—5213, 5254, and 5242 Films in Process ECN-2 Developer
    This variation of time and temperature are identical, but are presented the types of color negative films (for ECN 2). Variations of density, variations obtained for the same variation time (± 40 sec) and the same variation in temperature (± 4 ° F) in the ECN 2 (process color negative film for cinematografy)) are higher.
    It must be said that this information is quite indicative that the process of bobmercier time it has about 7 times greater than the variation shown in 131_05 Z and the temperature is below about 7 times the variation shown in Z 131_05. In my opinion, 131_05 Z data can not be extrapolated so far.
    After me, so high variations of time and temperature may occur color balance change for film.
    George

  2. #12
    RPC
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    This has been discussed before here on APUG by PE and others, and low temps with C-41 always result in crossover. It may be acceptable to some but likely not to most. Even if it can be fixed in software, wouldn't it be easier just to develop at the correct temperature, and have good negatives?

    RPC

  3. #13
    Greg Davis's Avatar
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    Quote Originally Posted by RPC View Post
    This has been discussed before here on APUG by PE and others, and low temps with C-41 always result in crossover. It may be acceptable to some but likely not to most. Even if it can be fixed in software, wouldn't it be easier just to develop at the correct temperature, and have good negatives?

    RPC
    Yes.
    www.gregorytdavis.com

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  4. #14
    Photo Engineer's Avatar
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    Quote Originally Posted by epatsellis View Post
    I'd love to see this done with control strips and densitometer measurements. On page 5-29 of Z-131, there's a chart showing the effect of low temperature on the various densities. at -4F from aim, there is a significant decrease in Dmax and Hd-Ld:

    Note that the densities decreases differently, based on layer order and the diffusion rate through each. While I imagine one could correct for some of the color balance change, there comes a point where I think you're approaching SOL.
    This mirrors what I have seen in my own darkroom and in experiments at EK. Nevertheless, the OP has shown some of the best results at 68F that I have ever seen, so there is some promise here. IDK how good this will be in the long run. As stated earlier, some gray scales are needed along with color patches and also a comparison with a "correct" process.

    PE

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    I've been down that road several years ago, with scanning, you might be able to get away with it, but if you look at the control strips, they're so cattywumpus that you wonder how the heck you ever were able to get something to even resemble white. What concerns me most is that we don't know what the original scene looked like, colors, etc. Now doing this with a Macbeth color checker would at least be a step in the right direction. But to dogmatically accept that the only thing that changes is density and saturation is just a little too far for me.

    In the words of the late Ronald Reagan, "Trust, but verify". Show me some standardized color patches, heck even a Q13 or Q14 gray scale would work wonders for illustrating color crossovers, btw. I realize not everyone has a densitometer and a box of control strips hanging around, so one of these alternatives would work nearly as well.

  6. #16
    Greg Davis's Avatar
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    Here is the post I made with my informal test last year. I did not show the 68°F shot because it was awful and could not be corrected to anything similar in density, color, and saturation of the others.
    www.gregorytdavis.com

    Did millions of people suddenly disappear? This may have an answer.

    "No one knows that day or hour, not even the angels in heaven, nor the Son, but only the Father." -Matthew 24:36

  7. #17

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    Because I do room temp. semi-stand with B&W, I tried similar reduced-agitation with C-41 at room temp a while back (not quite "semi-stand" exactly because I used the dev at full-strength). I have yet to scan or print anything (the purpose was to see if it worked at all), and I'm not using a "standard" C-41 kit (a local group was able to divide the chemical tablets contained in a decommissioned Konica processor's kit for hand tank use), but to my eye the negs look "normal" when using a fresh roll of film. As I recall I did 5 taurus inversions, left it for about 10 min, did another 5 inversions, and then left it for about 11 minutes. I then did bleach and fix steps also at room temp - I seem to recall I increased the time a bit for each step. Sorry for the imprecision, I don't have my notes in front of me right now.

    Anyway, if people are interested I can dig out the negatives and scan them in the next few days. It's an interesting experiment - I was pleasantly surprised to see that C-41 could work in those conditions at all.
    i can't wait to take a picture of my thumb with this beautiful camera.

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  8. #18

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    Don't want to get personal, but it looks like some people never run out of ideas how to ruin tons of film for usless results.
    Shooting film for quality reasons, but not willing to invest a few minutes to heat the developer does not make sense. Off-temperature C41 will always have questionable results, and even if it seems to somehow work one time, it will give unpredictable results the next time with a different motif, film, or developer. OTOH, a lot of "die-hard analog aficionados" accept unbelievable low standards for the results of their "labour of love".
    Everybody is free to waste his own time and money, but I guess a beginner will get a completely wrong picture of lab work from looking at all these "alternative processing" treads at APUG.

    Georg

  9. #19
    georgegrosu's Avatar
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    Georg, you have never tried something else than the recommended solutions?
    Perhaps some people go through such experience.
    Once you have learned something about film processing can try other options you see opportunities for you. Perhaps we are not able to understand why they try other ways of working. Or maybe they are not sufficiently understand the motivations for them tests.
    And me personally I do not feel justified procesing of C-41 at 20 °C.
    It is important to you to learn something of these tests.
    Requirements on the test results are different depending on the person.
    George

  10. #20
    RPC
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    Nothing wrong with experimentation, let's not discourage it.

    Based on what I have experienced myself, and what I have read here on APUG and other literature, I think it is unlikely that conventional C-41 chemistry can ever be made to give generally acceptable results at low temperatures, but that doesn't mean I would discourage anyone from trying. But I think a better solution would be to experiment with altered chemistry. Perhaps someone with chemical know-how and ambition could produce chemistry that gives good results at low temperatures with modern films. Unfortunately, there does not seem to be a lot of interest in color chemistry experimentation.

    RPC

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