BW dev + lab c41 instead of e6?

[SimonFreeman]

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]

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]

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]

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

[mts]

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]

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]

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]

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]

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]

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.