BW dev + lab c41 instead of e6?

SimonFreeman · Feb 29, 2012

Hi.

All the E6 labs in my area have shut down and buying the chems is not that cheap around here. I was hoping to somewhat emulate the E6 process by developing the reversal film in a BW developer, re-exposing it, re-spooling it and then taking it to a c41 lab.

First of all: would it contaminate the minilab's chemicals?
If not: any pointers for the BW bath? What developer to use, how long etc...

wildbill · Feb 29, 2012

What?
Tell us where you are and maybe someone can help with chemicals. Otherwise, mail it out for processing. I've never heard of your proposed approach but I can't imagine it would be anything like slide film or worth the effort.

keithwms · Feb 29, 2012

I have no clue whether what you propose will work but I am intrigued!

I think you'd want a maskless c41 film e.g. Rollei digibase.

fotch · Feb 29, 2012

Hi Simon and welcome to APUG. You managed to stump everone with your first post. Congrats.

mts · Mar 1, 2012

First, the B&W developer will NOT process the E6 layers correctly, although you could indeed stop, wash, and reverse the E6 film, and then dry it for subsequent processing. That has been the subject of another thread relative to testing bleaches. You could however mix an alternative E6 first developer from scratch, and there are threads here suggesting formulae.

Next, The C41 developer will not properly couple the E-6 dyes. Although there will be dye produced it is not likely to be at all satisfactory. E6 color developer is higher in pH (read more active) compared with the C41 developer used for negatives. The C41 developer is completely wrong to produce parallel curves in the E6 layers, although that doesn't really matter if you have already crossed curves by using the wrong first developer.

Finally, C41 bleach is likely to incompletely bleach the silver in the E6 layers. You will find retained silver. The fixers are similar in character, for whatever good that might do.

As to ruining the C41 chemistry, you are essentially cross-processing E6 film and unlikely to damage the C41 chemistry. However, I hope PE will comment on your idea. At any rate I wouldn't want to run that film through my C41 chemistry.

Bottom line is that E6 and C41 are different processes created with a lot of expense given to adjusting emulsions for their respective purpose. While it is possible to cross process E6 to yield what some might consider interesting effects, it's not a way to produce color negatives that compare with a proper C41 film.

SimonFreeman · Mar 1, 2012

Hello again.

Yeah, I'm aware that the colors could not turn out perfect, but I still want to give the process a try. This thread - apparently I can't post links yet, google: "bleaching out c41 orange mask" - has some interesting results by the same technique. The picture of a roll of Superia 800 on page 2 where the OP actually managed to remove the orange mask and produce almost normal-looking slides is really interesting.

So, what first BW dev and how should I use? Should I use a stop bath in case washing would not remove all of the first dev and the film would continue processing while waiting for c41 development?

And most importantly: Will it contaminate the minilab's chems? I'd like to try out the process on a few films before I order my own batch of chemicals.

As for me stumping everypody with my first post: I considered writing a more of a "hello, I'm new here"-kind of first post, but decided to go straight to the point.

Hello, I'm new here

Aristophanes · Mar 1, 2012

SimonFreeman said:
Hi.

All the E6 labs in my area have shut down and buying the chems is not that cheap around here. I was hoping to somewhat emulate the E6 process by developing the reversal film in a BW developer, re-exposing it, re-spooling it and then taking it to a c41 lab.

First of all: would it contaminate the minilab's chemicals?
If not: any pointers for the BW bath? What developer to use, how long etc...

What do you mean by "re-expose"?

You're doing a variant of cross-processing.

There are plenty of mail order solutions, but it depends on where you are.

SimonFreeman · Mar 1, 2012

By re-exposing I mean taking the film out of the tank and exposing it to light since I can't use chemical fogging like in E6.

I have a few labs I frequent and they always do xpro when I ask them to. In this case I'm worried that maybe the film would contaminate their chemicals since I have already souped it in BW developer. If I stop and wash, there won't be any developer left on the film to contaminate the minilab, right?

So yeah, it would be xpro for the lab. Me, I just want to get slides from a slide film. I'll be ordering a batch of E6 soon enough, but I still want to give this a try.

Chris Lange · Mar 1, 2012

What you've described is actually known as Film Acceleration, a very specialized form of cross-processing which allows you to shoot chrome films at speeds 2 or 3 stops under their box-speed. I have used it in the past for the effects that it gives. I have an old technical document from RIT which discusses it, but it seems to have been taken offline since I got it from one of their servers. I can scan the print out for you.

This email will be of use to you also, though:

http://people.rit.edu/andpph/pf-faq/faq-22.html

Take note though, you will NOT get a positive image from this process, you will get cross-processed negatives, which differ vastly from normally (just c-41) cross processed negs.

anikin · Mar 1, 2012

Hi Simon,

I think what you are describing should work. However, it would require quite a bit of experimentation to get the right amount of first development. The colors will be off, but you know that. I will leave the question on contamination to the chemists on the board. I suspect you will want some kind of a clearing bath (sod sulfite?) to wash off all of the first developer. A stop bath alone might affect pH of the C-41 processor, and I don't think operator would be very happy with you. How about getting a C-41 press pack chemicals and try the whole process on your own? It will get you to the result quicker.

Eugene.

holmburgers · Mar 1, 2012

In addition to a B&W developer, you'll need to bleach out the negative image silver that develops, otherwise your re-exposure will just result in density over the entire film.

Fascinating idea, and worth trying at least once. I shudder to to think what a dichromate/sulfuric-acid bleach (which will be necessary) might do to the coupler chemistry though.

There shouldn't be any damage from contamination, but that's assuming you've washed it properly after these steps.

SimonFreeman · Mar 1, 2012

Ok, so what are the steps I should take then? From what I've read it's simply:
1. BW developer
2. Stop (optional)
3. Wash
4. Second esposure
5. regular c41 process

Wouldn't adding a bleach step result in negative images?

holmburgers · Mar 1, 2012

Wait... I may have mispoke...

It just occured to me that the b&w negative image will be silver only (no dye), and thus will be bleached away in the C-41 process.

Check this out... http://www.flickr.com/photos/pochedunfou/sets/72157600128567295/with/472601937/

SimonFreeman · Mar 1, 2012

Yeah, I know about accelerating, but doesn't the process leave me with a negative image?

Next post I'll link you the thread where someone did exactly what I'm going for.

SimonFreeman · Mar 1, 2012

(there was a url link here which no longer exists)

Here it is, note the picture of a strip of Superia on the second page.

holmburgers · Mar 2, 2012

I don't fully understand this film acceleration stuff, and last night I laid in bed counting film layers (as opposed to sheep) trying to reason it out. Understanding that might help in figuring out what your proposed process might do.

Anyone care to make sense of it?

This is me thinking aloud about your proposal...

If you've exposed an E6 film and developed it in a b&w developer, you're turning the latent negative image to metallic silver without forming any color, because there is no color-coupling developer present (duh). By re-exposing it, and then subjecting this new latent image to a color-coupling developer (C-41 process), there will be formation of dyes only where there is developable silver; primarily confined to the positive image.

However, there will be a fair amount of developable silver even in the negative image, despite being developed prior. Your initial camera exposure won't use it all up, and your re-exposure will be complete; every remaining silver-halide will become developable. This might result in lots of strange colored fog(??).

Assuming the positive image dominates though, it seems reasonable that you'll get a positive color image of some sort (no doubt interesting).

Does that seem logical, or am I missing something?

p.s. Is this the superia shot you're referring to?

perkeleellinen · Mar 2, 2012

SimonFreeman said:
Hello again.

Yeah, I'm aware that the colors could not turn out perfect, but I still want to give the process a try. This thread - apparently I can't post links yet, google: "bleaching out c41 orange mask" - has some interesting results by the same technique. The picture of a roll of Superia 800 on page 2 where the OP actually managed to remove the orange mask and produce almost normal-looking slides is really interesting.

The post in question: (there was a url link here which no longer exists)

SimonFreeman · Mar 2, 2012

holmburgers said:
p.s. Is this the superia shot you're referring to?

Yeah, that's the one.

mts · Mar 2, 2012

There is no orange mask in your E6 film! Posts regarding bleaching out the mask are not relevant to your original post. Indeed there is an admixture of unexposed and developed silver following the first developer, because these unexposed grains will form the positive dye image when developed by the second (color) developer. Re-exposure (reversal) must completely expose all the halide that was not processed by the first developer.

Following first developer you need to use a color stop bath that is 1-2% acetic acid with 1% or so of bisulfite and follow that with a good wash. After drying the film could indeed be run through a standard C41 process that will develop the positive dye image, bleach its silver back to halide, and remove all the halide with fixer. Your lab will no doubt wonder how a positive image was created if you fail to tell them what you are doing.

A number of the replys to your original post have evidently mixed apples and oranges (or orange masks). The masking is a property of color negative film and is not present in positive E6 emulsions. An old American baseball manager named Casey Stengle once said, "doesn't anybody here know how this game is played?"

SimonFreeman · Mar 3, 2012

mts said:
There is no orange mask in your E6 film! Posts regarding bleaching out the mask are not relevant to your original post.

Yeah, I know that there is no mask in E6 film, why I referred to that thread was because I want to use the exact same technique, only on E6 film.

mts said:
Following first developer you need to use a color stop bath that is 1-2% acetic acid with 1% or so of bisulfite and follow that with a good wash. After drying the film could indeed be run through a standard C41 process that will develop the positive dye image, bleach its silver back to halide, and remove all the halide with fixer. Your lab will no doubt wonder how a positive image was created if you fail to tell them what you are doing.

How does the color stop bath differ from Ilfostop or any other BW stop bath? Can I tell my lab that the film is not going to mess up their chems then?

How long should the re-exposure last?

Thanks for your answer btw, your remark about mixing apples and oranges was spot on.

mts · Mar 3, 2012

Color stop baths contain sulfite usually as 1-2% bisulfite. The purpose is to prevent staining in the subsequent bleach. Otherwise it's the same stop bath as used for black and white imagery, so you can simply add some sulfite to your Ilfostop. It is good practice to include a stop bath following any color emulsion developer, RA-4, C-41, E-6, etc. with a wash following.

Once you complete the stop, say a minute or two, then you can process the remainder of your steps including color developer in room light. You should not contaminate the lab's chemistry but notify them that you are cross-processing E-6 to C-41, and that they should expect positive images and not to print the film.

Re-exposure in room light is about one minute per side of the reel. I re-expose film on stainless reels after a water rinse by holding the reel a foot or so in front of a 150W outdoor flood light that is mounted above my darkroom sink. Rotate the reel around in the light for a minute, then flip it over and rotate the other side and the job is done. It is a lot simpler and just as reliable in my experience as a reversal bath. Chemical reversal mostly facilitates automated processing machines. Obviously if you are going to dry the film following the first developer, stop, and wash then it will be reversed by hanging in room light while drying.

You might want to cut the film into two pieces after drying and then complete processing one strip with E-6 and send the other to your lab for C-41 finishing. Images of course should be MacBeth charts intermixed with a colorful scene, for example a mixed flower bouquet.

SimonFreeman · Mar 3, 2012

Thanks for your help. Now it's gonna take 2 weeks for my order of bisulfite to get here. No chance I could in the meantime try out the process without the appropriate stop bath?

Oh and is it possible to over-expose during second exposure? Can I just hang the film to dry in a room that isn't dark and let it stay there overnight?

mts · Mar 4, 2012

Try using sod. sulfite, also in 1-2%. You might find it at a shop that sells wine making supplies and it is also used as a preservative in some meat products, and of course in photo supply shops where it is almost every developer ever formulated.

In E-6 and C-41 the bleach and fix processes go to completion, as does the reversal step. You cannot overexpose. Think about it; the image detail develops in the first developer to a negative silver image leaving unexposed silver halides in the various color layers according to the amount of light that was received. These remaining halides represent the positive complement to the already-developed image details. Hence, the halides must be exposed completely in order to be processed by the color developer that produces a positive silver image and also couples the emulsions' dye stubs forming the positive dye image. In the bleach and fix the processing removes all the silver image components leaving the positive dye image.

You will notice that after the first developer there is not much evidence of the negative silver image owing to the opacity of the remaining halide. After reversal exposure and color developer, the film will appear almost black since it contains totally exposed silver negative and positive images as well as the coupled dyes. Once you bleach and fix, the film magically becomes transparent with a finished image, but it won't appear proper until the film has dried. For permanence it is important to go through the stabilizer bath. Modern C41 films contain the stabilizer in the emulsion so your lab may no longer use a formaldehyde containing stabilizer that is the last step in E-6.

Rudeofus · Mar 4, 2012

Sorry to rain on your parade, but it has already been mentioned here that C41 and E6 use a different color developer (CD4 vs. CD3). PE has not only explained that the wrong CD will yield poor colors, also the longevity of these colors is greatly diminished. Thread starter has two options to choose from in my opinion:

contact Tetenal Poland and see whether they deliver to Estonia. Poland is reasonably close to Estonia so shipping shouldn't be overly expensive
start completely home brewing E6. Recipes have been posted by stefan4u under the title chrome brew here on APUG, mts also has some formulas. Getting the chems may be a lot more difficult than getting an E6 kit, though.

ME Super · Mar 4, 2012

PE has also mentioned many times on APUG that the E-6 process requires a stabilizer containing formalin or formaldehyde in order to make the dyes stable, and that this stabilizer is not needed or used in modern C-41 processing. I don't know what will happen if you cross-process E-6 in C-41 chemistry, but when you get the Xpro film back from the lab, you may want to do a 1 or 2 minute wash in a solution containing formalin (don't wash them afterwards or you'll was the formaldehyde out!), then hang the strips to dry before continuing on with your use (mounting for projection?)

ME Super, aka The Slide Curmudgeon

BW dev + lab c41 instead of e6?

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