Bleaching out C41 orange mask?

Discussion in 'Color: Film, Paper, and Chemistry' started by Athiril, Sep 27, 2009.

  1. Athiril

    Athiril Subscriber

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    A while ago I started experimenting with reversing C41's at home to make positives.

    It just so happened my B&W developer of choice was Xtol and Rodinal/R09 one shot.

    So I started with Xtol as a first develoepr, originally barely getting any images, even after letting it sit overnight.

    Eventually got to the point where I was processing at 40 degrees celsius and experimenting with time, I found 40min+ Xtol 1+1 worked pretty well (and 2 hours for Rodinal/R09 1+50, agitation every 10 min)

    I used light reversal, then using C41 developer in place of the colour developer (since my C41 developer was used many times and well and truly exhausted, a process to completion was more consistent - until I exhausted it truly and it couldnt fully 'complete').


    Anyway, what I noticed with my Xtol results was that the orange mask was gone and I was looking at 'regular' chromes (Reala, Superia Xtra 800) - same process on Astia as well - but seems several stops over developed on Kodak EIR (I have 1 roll left, not using it yet).

    My Rodinal/R09 one shot results didnt affect the orange mask, I just got positives with an orange mask with those.


    I was wondering what it is in Xtol that is causing this?

    I was considering using a modified Mytol recipe (but a lot stronger, so I can have normal processing times) to do the same.
     
  2. keithwms

    keithwms Member

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    Sounds very interesting!
     
  3. Photo Engineer

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    You are talking about C41 films but mention reversal color films as well (E6).

    E6 films have no orange mask at all. So, there is nothing to "remove" in a reversal B&W process except the yellow filter layer which is bleached out along with the negative silver image. This is normal.

    If it bleaches the mask in C-41 films processed this way, then I suspect the bleach is doing the same to the mask.

    PE
     
  4. hrst

    hrst Member

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    I think the orange mask is explained quite well and in simple words in Kodak's technical document h2407, Processing KODAK Motion Picture Films, Module 7, Process ECN-2 Specifications:

    "The upper blue-sensitive layer contains a colorless coupler, which is converted to yellow dye during development, proportional to blue-light exposure. A yellow filter layer prevents blue light from reaching the two layers
    beneath, which are somewhat sensitive to blue light. The next layer is green-sensitive and contains a colorless coupler and a yellow-colored coupler, both of which form a magenta dye during development, proportional to green-light exposure. The residual yellow-colored coupler becomes a mask to correct for the unwanted blue absorption of the magenta dye. The bottom emulsion layer is red-sensitive and contains a colorless coupler and a pink-colored coupler, both of which are converted to a cyan dye during development, proportional to red-light exposure. The residual pink-colored coupler forms a mask to correct for the unwanted absorption of blue and green light by the cyan dye."


    So, am I correct that the reversal exposure just exposes the mask 100% so there will be no residual yellow- or pink-colored coupler left after color developer. If the film is processed in the normal way, the residual yellow and pink couplers AND the unwanted absorptions form the constant orange mask.
     
  5. Photo Engineer

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    No, you are not correct.

    Normal, color reversal processing of C-41 films will give a positive, masked image.

    Normal B&W processing should give an orange masked weak B&W positive image, but if I understand the OP, the mask vanished. But, the films mentioned are all E6 films.

    E6 films in a reversal B&W process would give nearly normal looking slides.

    PE
     
  6. pentaxuser

    pentaxuser Subscriber

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    PE doesn't the poster mention Reala and Superia as well which once reversed lost their mask with his process using Xtol?

    pentaxuser
     
  7. werra

    werra Subscriber

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    Reala and Superia are C41, aren't they?
     
  8. hrst

    hrst Member

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    Yeah, I've cross processed some ECN-2 neg in E6 and I got normal orange mask and a very low-contrast positive image. But how is it possible, then, that the mask vanished in OP's process with Reala and Superia? Very interesting.

    Further, processing E6 films in C-41 usually gives some interesting-colored Dmin, at least with Fuji films. With Sensia, it's green: http://sorsa-tv.ath.cx/~antalh/negadia-skan.jpg (tried making a slide from a negative film by exposing it on E6 film and cross-processing. It might have been with ECN-2 developer, if I remember correctly. I tried it because it has CD-3.
     
    Last edited by a moderator: Sep 28, 2009
  9. Domin

    Domin Member

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    I'm bit suprised that you need so much development. Recipes for so called 'acceleration' (b&w dev - fix - bleach - reexpose - color dev - etc.) called for quite long times but I remember something about 15 mins in xtol. I don't remember the dilution though.

    I have two partially processed rolls Fuji Internegative and quite expiered Kodak Farbwelt 100 (code FA 100-6) which I developed in Eukubrom 1+9 (paper developer at its standard dilution) 3min 20C and fixed. The image is clearly visible against light. Paper developer might be what you need.

    Did you process exactly same films in rodinal and xtol? In my experience seemingly similar films my behave quite differently when processed in way they were not intended to. For example some negs when cross processed in E6 need few stops overexposure and push processing (portra 400, xp2) while some work well at box speed (konica vx100) or look better underexposed (superia 100). The same goes for color balance - I've never actually found negative mask a problem, as some negs in E6 get blue cast (portra 400, fujicolor 200) rather than anything mask colored. Either way in most cases it can be more less corrected with color temp coversion filters.
     
  10. Photo Engineer

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    You guys are right. He mentions negative film.

    My eye caught the EIR and Astia and my mind went "E6 films". Thats all I can say! Sorry.

    As for the rest, I suspect that the B&W acid bleach may be bleaching out the dyes.

    Just a guess as I said above.

    PE
     
  11. AgX

    AgX Member

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    "Colour or not colour" in coloured (masking) couplers is dependant on an azo-group. Something not found on regular couplers nor on any dyes originating from couplers.

    If you can destroy just azo-groups, you can bleach the mask.


    PUG-couplers have that group too. The effect on them depends on what stage that bleaching is done.
     
    Last edited by a moderator: Sep 29, 2009
  12. Athiril

    Athiril Subscriber

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    Yes I processed the same films in Rodinal, they have the full orange mask.


    No its not B&W Acid Bleach, its C41 blix, all the chems are from a C41 kit, apart from adding in first dev and light reversal.



    Rodinal 1+50, 40c, 2 hours, 1 inversion per 10 min RAW scan
    [​IMG]

    Colour "Corrected"
    [​IMG]

    I started procesing this way as I was down to the dregs of my C41 developer and using it as a 'process to completion' developer was more tempting, at the point I started trying rodinal with it, I had re-used the same solution about 10 or so times - as you can see in this picture the colour developer has had it.

    Im waiting on some colour developer starter + colour developer replenisher (40 litres - Kodak E6) for which I will try this with as well.



    And yes the times really do need to be that long, as shorter times come out with basically no image.
    Reala, 24c, Xtol 1+1, 7min (light falloff is natural there - macro-photographed it hand held, thats where the backlight fell off).
    [​IMG]


    Here is 40c, 40min 1+1 Xtol, Superia XTRA800, night time shots, daylight balance on the RAW photo (daylight bulb in the light box thing), this was my first "sucess" at a reasonable result/image from processing this way.
    [​IMG]



    edit: since Im out of any kind of colour developer for a while, I will try making b&w negs by way of 'bleach' bypass/fix only.

    Since I have a stack of 35mm C41 film I probably wont other use now, since I've moved onto 6x7 and 4x5"

    I will process one in Xtol, one on Rodinal and see what I get.


    edit2: Also
    Found one of the earlier samples I did, mid 30s celsius, was a bit under developed.


    Photo of the frame info: [​IMG]

    'dry scan' with luminance levels for correct exposure
    [​IMG]

    An attempt at a colour balance...
    [​IMG]


    The later samples.. showed better 'raw'/dry colour (I wonder if thats from the 40min/40c - less orange mask though there is very little in this one, or the fact the later samples were not reala), and I still think there is a little orange mask in that one, but as you can see its virtually not there.


    And I mentioned Astia earlier... Astia came out with great colour 'raw'/dry, I'd say near balanced even.

    Im looking forward to trying Xtol with Real E6 colour developer.
     
    Last edited by a moderator: Oct 1, 2009
  13. Photo Engineer

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    Well, I have no idea what is going on.

    PE
     
  14. keithwms

    keithwms Member

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    But it is kinda cool!
     
  15. georgegrosu

    georgegrosu Member

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    I have a process compatible with the E6. When I make the proces I had a number of difficulties in finding the composition and working parameters to b & w developer. More over, the film Velvia 50 go good and with Provia 400 I had problems with fog.
    I know the chances that a picture go good is to have white and black ok. The other colors go on the curve.
    Shooting a color scale with different exposure (normal ± 1 stop).
    Take 3 pieces of exposed film which is: (normal and ± 1 stop). Then developed into b&w developer with 3 times. + 15% of your time, normal and - 15% of your time. Introduction the tests exposed in the spiral successively. The above times indicated.
    I never processed color negative film in E6 process.
    In my opinion, should not we have a big fog (mask).
    The density of the fog in photo color negative films is small.
    The density of the fog color film negatives –cinematography are high, especially in yellow (~ 0.9).
    You must obtain a little fog and some reasonable maximum acceptable density.
    One can see that the more times in the first developer the maximum density will be lowered.
    If you can you can replace the color developer CD 3 with CD 2 is good.
    You have a better contrast and image balance.
    My suggestion is make a prebath with 20 g sodium carbonate (anhydrous) /1000 ml water. 3 minutes with 30 – 35 º C. Prebath before the b&w developer.
    You can see the color of the prebath go after treatement. Wash after prebath is good.
    George
     
  16. Photo Engineer

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    Use of CD2 or CD4 with E6 films will reduce image stability and cause color purity problems. E6 was designed for CD3.

    PE
     
  17. georgegrosu

    georgegrosu Member

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  18. Photo Engineer

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    I don't think that there is a suggestion that you do that. I believe that one reference line is in error. CD2 used to be used with ECN, but they changed to CD3 for greater stability of the developer and dyes. CD2 was known also to cause a problem with dermatitis.

    PE
     
  19. hrst

    hrst Member

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    That figure shows what will happen if you contaminate your developer with the wrong CD. The whole paper is for showing what will be the effects of different kind of contaminations or processing faults. These are not suggestions...

    And, as you can see from the curves, the effects are quite large on color balance and speed.
     
  20. georgegrosu

    georgegrosu Member

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    In “Effects of Mechanical & Chemical Variations in Process ECN-2” - Figure 8-6 Effects of CD-2 and Stop Bath Contamination—5217, 5242 Film in Process ECN-2 Developer- is passed to CD 2 - Substitute CD-2 for CD-3. For hrst.
    The notion of contamination, for me, refers to little concentration. Concentration of 0.5 - 1.5 g / l CD 2 is enormous for an impurity. For me it's a disaster for a film processing laboratory.
    George
     
  21. georgegrosu

    georgegrosu Member

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    Agfa have a brochure stating that the color print can be processed in ECN II developer. http://www.dump.ro/imagini/agfa2-jpg/11768 (Here is the reference to the scanned brochure from Agfa.). Some laboratories have applied this method for economy. No more warm for hot the positive color machine ECP 2. We must give other parameters for printing.
    George
     
  22. Photo Engineer

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    Nevertheless, CD3 is currently used with ECN films. CD2 is not recommended.

    PE