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  1. #11
    justin parker's Avatar
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    Quote Originally Posted by stefan4u View Post
    Dear Justin.

    Actually your last plot looks very good, the curves seems to be MORE parallel than the curves from the reverence strip. If using Flexicolor I had mostly times of 3:25 min, somewhere in the processing manual is written that times can be adapted within certain ranges to maintain an optimal result for rotary procesing. You don’t have to stick at 3:15, a drum development is simply different from a continuous industrial development machine.

    Does your sidekick do a wash step after development? If so, skip that and go directly to the bleach step, or preferable to a stop bath prior bleaching.

    And this may be the most important part; a prewash is originally not intended in C41, this will lead to (slightly) different densitometer readings than with films processed without prewash. This you can read somewhere in the process manual. The trick is that you normally do not see the difference in the print, and a proper tempering in home processing is quite a struggle without prewash. So it’s a bit up to you weather you want chase behind process results of a different development machinery (continuous cine type machines or minilabs) or accept minor differences and try a print first, to get an overview of the “visible quality” of your Process. Again, your curves look more parallel than the reference…

    Regards, Stefan
    Stefan,

    Thanks very much for your kind encouragement. You are right and you motivated me to go back and read through the section on rotary processing in Z131 (section 3). I had read through it back when I bought my Jobo but I never had a densitometer or control strip then. Once I got those I read through section 5 on using the control strips, but everything in there is quite focused on replenished continuous systems, in terms of advice. You are right that it says in fact for rotary procesors:

    If the control-strip density values plot within the processcontrol limits for LD and HD – LD, you do not need to adjust the developer time. If the LD and HD – LD parameters plot significantly low (out of control limits), then increase the developer time slightly on each subsequent process run until the control-strip plots are in control. Usually an adjusted developer time that produces good control-strip densities falls somewhere between 3:15 and 3:45.
    The Sidekick does not do a wash step between developer and bleach. (For this reason I am skeptical about reusing the bleach, but that is something to look at later after I get C-41 and 4-bath E-6 up and running.) However it DOES DO A PRE-SOAK before the developer. This is because the Sidekick doesn't have any tempered water bath. The pre-soak appears to be set to heat up actually a few degrees higher than the developer is calibrated to in an apparent effort to compensate for the cooling of the reels and film. (I know PE and others say to use two quick prewashes for this reason.) The drum has a temperature sensor inside of it and there is a hot air blower that blows hot air on the outside of the drum during steps to maintain the temperature of the chemicals in the drum. My current thinking is that because of the pre-soak the developer does take longer to get into the film. (As is the case for black and white.) Since the temperature is higher though it might be less of a difference, but because their are three+ emulsion layers perhaps it is actually more significant. Unfortunately if that is the main source of the issue that there will be some variation from film to film stock to film stock. There is also the issue of how the 3:15 is timed in terms of filling and draining the drum. So I am thinking I will try running it tomorrow at 3:45 and see how the strips look.

    You are right that the test strip curves look quite parallel. And I am actually very pleased with the way the negatives scan. I am sad that I have never had the chance to make an optical color print, but I do hope to someday. Here is a scan from a Fuji 400H 220 negative I processed in the Sidekick. I feel I am getting better colors than I was getting from my local pro store and their Afga minilab processor. But it might just be my own bias towards not wanting my effort to be in vain.

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  2. #12
    Rudeofus's Avatar
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    I don't claim to play in the same league as PE or stefan4u, but from reading the instructions in my C41 kit it has to be expected that colors and densities are a bit off when the kit is used as is. My kits specifically list instructions how to adjust colors with various additives. I guess these are rarely discussed here because so few of us use test strips
    Trying to be the best of whatever I am, even if what I am is no good.

  3. #13
    Greg Davis's Avatar
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    Is your developer CAT No. 175 6337? If so, it is a 2 liter mix, so perhaps your extra liter of water is diluting the developer way too much. Read here.
    www.gregorytdavis.com

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

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  4. #14
    justin parker's Avatar
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    Quote Originally Posted by Greg Davis View Post
    Is your developer CAT No. 175 6337? If so, it is a 2 liter mix, so perhaps your extra liter of water is diluting the developer way too much. Read here.
    No it is CAT No. 5283973. (http://www.minilab.com/productdetail..._A_skuID_E_576)

  5. #15
    justin parker's Avatar
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    Quote Originally Posted by Rudeofus View Post
    I don't claim to play in the same league as PE or stefan4u, but from reading the instructions in my C41 kit it has to be expected that colors and densities are a bit off when the kit is used as is. My kits specifically list instructions how to adjust colors with various additives. I guess these are rarely discussed here because so few of us use test strips
    Rudeofus, which kit do you use? I haven't seen any mention of additives when reading through the Flexicolor instructions. I do know that for E-6 though I have read that you will want additive to tweak color balance. I haven't got to E-6 yet though.

  6. #16
    Rudeofus's Avatar
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    I use Tetenal kit and you are correct, the instructions I had in mind were for E6, my bad. I guess they thought that C41 material can be filtered during printing so there would be no need for color correction during development.

    If you look at the color correction instructions for E6 (e.g. here), you see that they affect the CD bath which is also present in C41. Note that very different dyes are used for C41 so colors will be affected differently. The concept, that NaOH (i.e. higher pH) and H2SO4 (i.e. lower pH) affect color balance, can probably be extended to C41, though.
    Trying to be the best of whatever I am, even if what I am is no good.

  7. #17
    Greg Davis's Avatar
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    If it is for replenishment, then you may need to use a starter to get it within tolerance.
    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

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