A (not yet refined) method to bleach C-41 orange base

[decolorante]

(Thought for some time whether to post in the Color or in the B&W category, but given the reasons for doing this I figured it'd be more interesting to people shooting black and white.)

So, what do you do when you are out of money and have a big supply of cheap, unused C-41 film that you want to soup in your favourite developer and throw under the enlarger on a big, lush sheet of old-style fiber based B&W paper?

There's much talk on how to do this but the orange base REALLY bothers when you try printing on variable contrast paper, especially the orange-safelighted ones. I looked around the net for much time but everything I found was that removing the orange base somehow required harsh processing that was also going to also strip away the image from the film.

I am doing some experiments with household bleach with some success; since it seems to be scarce, I am reporting here for everyone who might be interested in that, and for the community to refine:

Take an already developed, fixed, rinsed, dried negative and dip it in common "5%" household bleach diluted 1:5 in tap water.

The bleach usually strips the gelatine away in strong concentrations, leaving only a transparent strip of plastic; but if you look carefully you can see that at this dilution, after some minutes, the orange base starts to diffuse off the neg before the gelatine comes off.. but not that much before! when you see that the gelatine at the edge of the film starts to get consumed, pull out the negatives and rinse immediately.

I have found that the gelatine isn't any weaker than before, and doesn't come off even with turbulent rinse. In this way it is possible to remove the orange base from my C-41 negatives and only get a little of edge munched away by the bleach.

Pointless? Maybe! But it could also be that someone will need it sooner or later.
If someone can help testing or refining the "recipe" it is very appreciated.

P.S.: Film was Ferrania Solaris 400. Since C-41 is a very standardized process I am expecting that there will not be much difference with other films, but this is an unknown.

 

[Sirius Glass]

The orange mask is used so that color prints will be properly color balanced and each color will be correct as possible.

Since your problem comes from using variable contrast paper, if you used graded paper you results may be better. Kodak used to make a paper called Panalure (long discontinued) which was designed to do exactly what you want. It was sensitive to all colors (special safelight or no safelight) and worked pretty well.

If you can find a stash of Panalure, let me know because I would like to stock up on it.

Steve

 

[Photo Engineer]

Not all film hardeners and film subbings are the same. Therefore, what works with the film of one manufacturer may not work with that of another. You will not know until you test them out.

PE

 

[decolorante]

Yeah, I should have thought about that. Anyway this was some kind of experimentation, the point was to work with what I had and see if I could get something out.

I have heard about Panalure but I think it was discontinued long before I even heard about photography...

About the graded papers, of course that's a better solution. I guess it would only be a matter of longer exposures in that case.

 

[Vlad Soare]

I think the problem with enlarging color negatives onto black and white paper lies not just in the orange mask, but in the image itself. The orange mask merely adds overall density, like fog, which can be printed through. On the other hand, different parts of the image are made of different colors, to which black and white paper is sensitive to various extents. That's the real challenge, not the mask. The mask is just an annoyance.

I had some limited success ten years ago with color negatives enlarged on hard graded paper (I believe that our "hard" was equivalent to what's called grade 4 in the US). The results were acceptable, though nothing to brag about.

 

[michaelbsc]

I think no small part of the problem is that enlarging paper, even graded instead of VC, isn't panchromatic. Hence the varying sensitivity you mention.

 

[holmburgers]

One more thing, the base is actually not what's orange. The orange is actually in the emulsions layers and is a combination of a reddish & a yellow dye used in masking the cyan & magenta layers. Therefore I would think that anything that could bleach the orange away, would also be bleaching away the image.

 

[Gerald C Koch]

Why not omit the bleach step and keep the silver image. This would be like using a staining developer and make printing easier..

 

[Sirius Glass]

To state the obvious, just shoot black & white film instead. Then you would be enjoying photography rather than playing junior chemist.

Steve

 

[decolorante]

Vlad, Gerald: what I was actually talking about is C-41 film cross developed in b&w chemistry.

Sirius: I do both. I enjoy properly done black and white photography much, but at times my inspiration drops. I find that a little experimentation and fiddling overall restores my creative vein.

 

[2F/2F]

Why not omit the bleach step and keep the silver image. This would be like using a staining developer and make printing easier..

I wouldn't worry as much about the orange mask as I would about contrast. Color issues aside, C-41 negs are very low in contrast compared to b/w negs, so they print flatly on b/w paper (and b/w negs print contrasty on color paper). There is also the fact that you are using colored dye layers as your density, instead of silver. So, you need to add contrast by increasing the dye density, or better yet, retaining the silver in the emulsion.

Mr. Koch's could be a good suggestion, though I have not tried printing skip-bleach negs on b/w paper myself. Skip bleach processing can be done by some labs, and very easily by home developers. It certainly adds contrast to color negs, which is what you need when printing them on b/w paper. Whether or not the tonality will go too haywire even for b/w printing is a question, though.

You can also try developing the film in b/w process. It works, and is more controllable than skip bleach processing.

All three options (heavy overdevelopment, skip bleach, and b/w process) are probably worth trying at least once, though my guess is that your best and most controllable results will be with a standard b/w process.

 

[2F/2F]

Forget to mention lith printing. You can do that from normal color negs.

 

[jm94]

I had some kodak C-41 black and white BW400CN that had a completely one-of-a-kind shot involving my younger sister doing some abnormal gymnastics she has ever done! She did them "accidently" when falling off a family friends trampoline and was already trying to take a photo of her on it and instinctively hit the shutter as she fell.... (it was quite a nasty fall, down 1M from the side, she was in the air in the most abnormal position)

Developed at the shop, months ago before i setup my own darkroom, and given one print. I decide to enlarge it yesterday optically (better than a digital print) and... nothing. exposure of 5x7 at F4.5 10 seconds... 20 seconds... 40 seconds gives me a faint image... 90 seconds gives me an O.K image, i end up exposing for 110 seconds to get the image decent!
The orange mask is very, very annoying and as someone else mentioned somewhere on here? acts as a "safelight filter" to a degree. I wouldn't dream of using this method to remove the mask on a one-of-a-kind negative, but if i did a contact copy i would give it a shot... With C-41 B/W there was no point what so ever in having the orange mask, none of the older C-41 b/ws did! I will shoot a test roll and get it processed at the lab dev only and will give this a shot... will let you know of my results!

 

[Vlad Soare]

Vlad, Gerald: what I was actually talking about is C-41 film cross developed in b&w chemistry.

I see. It makes sense, then.

 

[Gerald C Koch]

You could expose the negatives to strong sunlight for a few days. This may bleach the orange dye. This technique is sometimes used with overly dark color slides.

Kodak used to publish specific bleach formulas for each of the three color layers in slide films. Perhaps the bleach for yellow dye would help.

The main problem with using color neg film for this purpose is the small amount of silver actually in the emulsion. This produces thin negatives that are hard to print.

 

[michaelbsc]

I had some kodak C-41 black and white BW400CN that had a completely one-of-a-kind shot involving my younger sister doing some abnormal gymnastics she has ever done! She did them "accidently" when falling off a family friends trampoline and was already trying to take a photo of her on it and instinctively hit the shutter as she fell.... (it was quite a nasty fall, down 1M from the side, she was in the air in the most abnormal position)

Developed at the shop, months ago before i setup my own darkroom, and given one print. I decide to enlarge it yesterday optically (better than a digital print) and... nothing. exposure of 5x7 at F4.5 10 seconds... 20 seconds... 40 seconds gives me a faint image... 90 seconds gives me an O.K image, i end up exposing for 110 seconds to get the image decent!
The orange mask is very, very annoying and as someone else mentioned somewhere on here? acts as a "safelight filter" to a degree. I wouldn't dream of using this method to remove the mask on a one-of-a-kind negative, but if i did a contact copy i would give it a shot... With C-41 B/W there was no point what so ever in having the orange mask, none of the older C-41 b/ws did! I will shoot a test roll and get it processed at the lab dev only and will give this a shot... will let you know of my results!

It should print as a normal B&W image of you "color" print it on RA4 paper.

That's the idea of the film, totally process as a minilab "normal" workflow.

 

[decolorante]

You could expose the negatives to strong sunlight for a few days. [...] The main problem with using color neg film for this purpose is the small amount of silver actually in the emulsion. This produces thin negatives that are hard to print.

I see. Also I have done more experimentation and noticed that the `bleaching`, more than removing the orange dye, sort of turns it into a neutral density fog. So foggy and low contrast, but still neutral density and fine grained.

Interesting point, that the sunlight could actually cause the dyes to fade but not the metallic silver image. This makes sense, don't know how much convenient it might be though.

 

[CBG]

Might be "easier" to make a dupe BW neg on BW film, and then do printing from that. BW neg stock is fast enough that the masking effect should not make for bad exposure times. Likewise you could use filtration to adjust tonal rendering in the duping step.

 

[mattmoy_2000]

If you develop in a standard BW developer, the dyes won't form (as there is no colour developer). This just leaves the colour couplers in the gelatin imparting fog. I believe they can be removed using a mixture of Fix and citric acid, as I read once in a Kodak Tech Pub.
It's only if you actually C-41 develop the film that you get the orange mask, from what I've read.

 

[mattmoy_2000]

Found it:
http://www.kodak.com/global/en/consumer/products/pdf/ae31.pdf

 

[Photo Engineer]

Please read that again. It only works with E6 and Kodachrome films and is intended to remove the yellow filter layer, not the mask.

PE

 

[michaelbsc]

If you develop in a standard BW developer, the dyes won't form (as there is no colour developer). This just leaves the colour couplers in the gelatin imparting fog. I believe they can be removed using a mixture of Fix and citric acid, as I read once in a Kodak Tech Pub.
It's only if you actually C-41 develop the film that you get the orange mask, from what I've read.

So the orange mask is formed during development? Not something that is intrinsic to the film?

If so then regular old B&W dev, stop, fix ought to work. To be sure the film is hardly optimized for that process, but it may be better than no pictures at all.

 

[holmburgers]

...the base is actually not what's orange. The orange is actually in the emulsions layers and is a combination of a reddish & a yellow dye used in masking the cyan & magenta layers.

That's what I was trying to say. There seems to be a broad misconception that the base is somehow orange, but it's not. The orange comes from dyes just like the image colors do, except that they are inversely proportional to the image, and their color is the "inverse" of the unwanted absorptions in the dyes... hence corrective color masking.

 

[Photo Engineer]

You know, I am tired of these misconceptions. The mask is built in at the factory! It is an overall orange color. During development it forms a positive orange image mask. The orange color is there from the very start though.

 

[holmburgers]

Ok, I was wrong in the sense that color-coupling development brings about the orange color, but it is the couplers themselves that are colored, and these are destroyed image-wise (is this more accurate?). The base however, is not orange.