Bleaching out C41 orange mask?
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.
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.
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.
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.
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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?
Originally Posted by Photo Engineer
Reala and Superia are C41, aren't they?
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 hrst; 09-28-2009 at 04:07 PM. Click to view previous post history.
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.
Originally Posted by Athiril
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.
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.