debug my RA4 process? (insane contrast)

Discussion in 'Color: Film, Paper, and Chemistry' started by polyglot, Jun 15, 2012.

  1. polyglot

    polyglot Member

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    I've just started RA4 but am having trouble with the contrast being stupidly high. Witness a dodgy iPhone photo of the print:
    [​IMG]
    compared to a scan of the negative (compare forehead vs green cushion!)...
    [​IMG]
    That's from Portra 160 I developed at home in brand new Fuji chemistry.

    Process details are:
    - Ektacolor RT/LU, mixed up 1L of developer-replenisher (40+17.8+40mL into 1L as per J39)
    - separate bleach and fix, mixed at 1+4 and 1+6 respectively (same concentration as they would each be individually in the blix)
    - 200mL working solution, to which I added 5mL starter (j39 says 25mL for 1L of solution)
    - remaining 800mL used as replenisher at 10mL/sheet
    - Fuji Crystal Archive
    - process in Jobo at 35C as per Table 5 of J39 but separated blix:
    - 1:00 prewash, 2 baths (some blue dye comes out)
    - 0:45-0:50 develop
    - 0:30 stop bath (2% acetic)
    - 0:30 wash
    - 0:45 bleach
    - 0:30 wash (3 dumps of water)
    - 0:45 fix
    - 2:00 wash

    I don't have any control strips :sad:

    The filter pack is 15M 10Y, which seems a little on the cyan side. Might be that my enlarger bulb is dim (it's a 200W in an enlarger with cooling intended for a 250W so might be running cool).

    Reading Ctein's Post Exposure indicates that crazy contrast might be due to insufficient "Part A" in the developer. I measured it to within less than 1mL (2%) though and it was the same quantity as Part C. And the tide in my Part A and Part C bottles is the same.

    The stupid contrast looks sort of like bleach-bypass processing to me however "dead blix" is generally listed as giving a yellowed Dmin and my whites borders are quite clear. I'm going to mix up some combined blix as per instructions now to test whether the separated operation is breaking anything. I've also got some lab-developed negs here to test with in case my C41 process is whacked but I control that pretty tightly and my home-souped negs don't look contrastier than the shop-souped ones.

    Desperately seeking ideas...
     
    Last edited by a moderator: Jun 15, 2012
  2. markbarendt

    markbarendt Subscriber

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    Color balance seems to be one issue, that may be part of the issue.
     
  3. E76

    E76 Member

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    It could be a measurement issue. When you mix such small quantities your precision needs to be extremely high. This is why Kodak does not recommend mixing any less than the full 10L at a time, which I would do anyway. If stored properly, the RA-RT chemistry lasts a very long time with replenishment (almost a year in my case).

    I'm a little confused by your fixer step at the end since you are using Kodak chemistry. Why did you decide to separate it? It's possible that your bleach is not working correctly and you have some retained silver in the print, which will decrease saturation and increase contrast.
     
  4. Photo Engineer

    Photo Engineer Subscriber

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    As you say, the contrast is too high, but the balance is also too blue.

    Some report that Fuji CA has higher contrast than Endura, but it is also true that many papers just cannot get the full tone scale seen in a negative scan.

    PE
     
  5. markbarendt

    markbarendt Subscriber

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    Good catch E76.

    If I remember correctly RA "Blix" is more efficient at it's job than separated RA "bleach and fix" steps.
     
  6. polyglot

    polyglot Member

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    I'm pretty confident of the measuring, since the syringe approach has worked very well for me with both C41 and E6 - I have perfect chromes after making up 1L batches from a 5L kit. Same sort of ratios as here. Perhaps J39 is not applicable to RT/LU and the ratios are a bit different - the concentrate bottles don't state their contents volume so I can't divide the volume by 5 myself without pouring it all out to measure and therefore losing some to left-behind drops etc.

    I just did a test with blix instead of separated bleach+fix and the contrast* is unchanged, so I don't think the problem is that separation. The reason I separate them is because of the shelf-life once mixed: I can store a litre or two of bleach or fixer on the shelf for months to a year but as blix, the bleach will eat the fixer in a couple of months. According to PE, separating them is fine and my test seems to confirm that the separation didn't change anything.

    In terms of mixing the developer, I could make up a full 5L (it's the 4x5L kit) and store it in a wine-bag. That's about 300-500 sheets worth though so I'd want to be sure it was going to last a year or two without refrigeration! I can store a 1L bottle in the fridge without getting into too much trouble but a cask would have to sit in the cupboard. Actually I think I'll just do this anyway - I have 4 of the 5L sets, which even if this one dies in a year, will still be lots of printing. And it will allow me to determine if J39 is applicable.

    Edit: it may or may not be too blue. The white cloth in the right of the frame appears as a neutral grey. I think the crazy look of the skin is just due to the contrast and/or my bad phone-picture.


    * actually the print is badly cyan-fogged but I assume that's due to my darkroom not being properly light-tight in the daytime, whereas the print I posted above was done at night and has no fogging. Other than the cyan, the print densities look the same with blix vs separated bleach+fix. Unless somehow going to the blix could cause a massive and uneven shift to cyan...
     
  7. Photo Engineer

    Photo Engineer Subscriber

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    Blix vs bleach then fix is not problem here. Don't worry. The bleach then fix was and is used commonly by some processors for color paper and should be used for all film processors.

    All Kodak chemistry I have has volumes printed on each part so as to make up a good small batch. So, this may be the problem as the ratios are different from those I used for the replenisher, but then things change over time. I suggest you check the pH. It should be 10.5 when ready to use. If it is not, then there is a mixing problem. As pH goes up, contrast goes up.

    PE
     
  8. polyglot

    polyglot Member

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    I got a good print out of it but changed about 3 things. Narrowing it down now.
     
  9. polyglot

    polyglot Member

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    Well, I don't know. I now suspect that my C41 process is overdeveloping.

    I've made a good print from some test shots that I had developed at a lab. I've also made good prints from an identically-exposed roll that I developed at home, except that the print exposure required differed and there is slightly more contrast in the print from the home-developed negative.
    - Lab neg prints at M15 Y7.5 and 2.7 stops (6.5s); about 2CC blue and a tad underexposed
    - Home neg prints at M7.5 Y5 and 3.5 stops (11.3s); looks damn good, though much contrastier than I expected from Portra160!
    The negs look practically-identical to the eye though.

    The print from lab-souped film (you can tell I shot this to have a good selection of colours and tones):
    [​IMG]
    And from home-developed using Fuji Hunt 5L kit:
    [​IMG]
    Sorry I don't have a flatbed scanner, just film scanners :wink:

    The iPhone-photos over-state the difference in brightness between the two. The former does have better brightness in the wooden table but it has less overall exposure and the latter shows much better highlight detail, especially in the HP5 & Acros boxes. While these differ slightly, the still-significant contrast of the lab film indicate to me that perhaps this paper is just really high-contrast. And maybe I over-developed the baby-photos roll; still got a few more combinations to try yet...

    I vaguely recall that it's possible to reduce contrast chemically, e.g. by adding sulfite or something to the developer. Which sulfite? How much? Say I wanted a 1-stop contraction, what would I do?
     
  10. Athiril

    Athiril Subscriber

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    Did you add the 24mL of RA developer repenisher additive?

    Did you develop in straight replenisher? Or did you dilute it to working solution and add starter?

    http://www.kodak.com/global/en/professional/support/techPubs/cis49/cis49.pdf


    edit: Just looked at the data more closely, 40/17.8/40 matches up to RT working strength (instead of replenisher) without the additive. But it's still sans starter. I'm under the impression it's RA you don't need the starter for, not RT.
     
    Last edited by a moderator: Jun 16, 2012
  11. polyglot

    polyglot Member

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    I thought maybe that CIS49 had told me my error (leaving out the dilution of replenisher into working solution step) but the ratios come out the same. I mixed it directly to 4% Part A as per J39 rather than indirectly to 5% part A, then dilution by 1.2 and adding starter to get tank solution.

    I have Starter but not Additive. My impression is that the latter is an optional thing to increase tank life, so I was following the "without Additive" path.

    If you look at my original post, there's 5mL of starter in the 200mL of working solution that I made up.
     
  12. CatLABS

    CatLABS Subscriber

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    When i was younger, photo paper emulsions came in three contrast grades (both fuji and kodak).
    The contrast difference between kodak supra and ultra papers, was HUGE.
    Color balance was also extremely different, and shifts often went in opposite directions.
    Same for Fuji (C or B or how ever they graded their paper, they only started selling fuji papers when i was almost done using the kolenta), but it was still the same thing with the high and normal contrast papers. Light and day. I do not know if there is more then one emulsion for paper nowa days. If there is - just switch to the lower contrast paper.

    Ans of course as someone suggested above me, you cannot compare a scan to a print because of the large dynamic range discrepancy.
     
  13. Greg Davis

    Greg Davis Subscriber

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    Did you add starter to your C-41? I missed that once and got very contrasty negatives.
     
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  15. hrst

    hrst Member

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    Fuji Hunt 5 liter kit does not use a starter, it's built-in to produce tank solution. There are just parts A+B+C.

    I get perfectly normal contrast with Fuji Hunt 5 liter kit, Kodak RA-4 chemicals sold at AG Photographic and both Kodak Supra Endura (now discontinued) and Fuji Crystal Archive (bought in 2009 or so).
     
  16. polyglot

    polyglot Member

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    krifartida: indeed, it's just high-contrast papers available now, because 99.999% of it is used for digital printing where one can do all the manipulation pre-exposure. I would buy some Portra paper... except I can't.
     
  17. hrst

    hrst Member

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    If you do your own C-41 processing, it is so easy to underdevelop a bit (15 sec, for example) to address the problem of only higher contrast papers remaining.

    You can also add a bit of sulfite (for example, 0.5 g of sodium sulfite per liter) to the RA-4 developer to lower the contrast. This won't affect the shelf life.
     
  18. Photo Engineer

    Photo Engineer Subscriber

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    I've been thinking about this. You know that high contrast problems seem to be on the rise. Am I mistaken or not? If so, it may be of interest to compile the incidents and the solutions into a single thread or something so that it is available for all to see.

    PE
     
  19. polyglot

    polyglot Member

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    hrst: I will definitely be trying C41 pulls, I'm just grumpy about the big pile of already-developed rolls I've got from my honeymoon last year. Quite a few in there I want big optical prints of.

    Thanks for the sulfite directions; I'll have to get some and try it.

    I've had a couple more successful prints today from different rolls. I'm starting to suspect that maybe that baby-photo roll is overdeveloped, though the contrast doesn't (eyeballing the neg) look any worse compared to the ones I've printed successfully.
     
  20. Athiril

    Athiril Subscriber

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    polyglot can you put the baby neg in your film scanner and take a preview screen shot of the preview histogram (the scanner histogram pre-adjustments) and do the same for the lab vs home developed negatives from the two comparison prints and post them? This will at least show comparative density ranges.
     
    Last edited by a moderator: Jun 17, 2012
  21. polyglot

    polyglot Member

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    Athiril: will do; probably tomorrow. I figured I'd try some negs shot in flatter light and have had roaring successes with some Reala that I shot in St Petersburg, so I now think I've got the RA4 process working properly, modulo a few unfamiliarity-frustrations.

    I have my suspicions that my problems with the baby photo might be a combination of too-blue (veins show) in conjunction with under-bleaching (yellow Dmin, though the borders were clear). I'm now bleaching for 1:15 instead of 0:45 and finding it easier to balance the colour. So I'll revisit it sometime this week.

    Thanks all for your help.
     
  22. Athiril

    Athiril Subscriber

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    They've been post-processed, so I cannot tell anything from the histograms.
     
  23. polyglot

    polyglot Member

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    They're raw DNG scans. No processing. If I open them in VueScan as "Image", then they appear as negatives - they've had no inversion or anything.
     
  24. Athiril

    Athiril Subscriber

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    They've been post-pro'ed by vuescan, colour balanced and levels. Both images are using the whole histogram range almost. I doubt your negs are much above a dMax of 2.0, let alone 4. I don't think your negs are filling the entire range of the scanner.

    Given that, I can't infer any relative density range differences.



    Other option would be to take readings directly through the film.
     
  25. Tom Taylor

    Tom Taylor Member

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    I don't know about the rest but your starting filter pack seems a little off to me. The usual recommendation is to start with a filter pack of 0C, 45Y, 45M, run a test strip to determine exposure and once the exposure is determined to adjust the filter pack to eliminate any color cast. My final filter pack is (usually) 0, 45, 55 with CA.

    Thomas