a question about E-6 Reversal bath

[quiver]

I was just looking at the Fuji E-6 formula] and I was wondering how the reversal bath works. I figure that the stannous chloride is used to remove the silver negative image. What has me puzzled is what chemical exposes the remaining halide for the second developer? I don't think that a light source is used anyway.

 

[quiver]

Never mind. Further research (which I should have done before posting) indicates that stannous chloride is the fogging agent. Now all I need to do is figure out a what I need for a fogging bath.

 

[PHOTOTONE]

You could just use exposure to a photoflood lamp. These are usually bright enough to do the job, even with the film on the reel.

 

[quiver]

I probably should have mentioned the application for this. What I am trying to do is to apply the Anderson process to film. It is my hypothesis that the contrast of MP film can be increased by this method. This would allow this material to be printed on standard photo paper with ease. Handling the film with its loose remjet backing isn't a very good option in my opinion. Consistency could also be a problem with the light bulb method. A chemical fogging step would appear to be more consistent and less of a hassle.


Jargon note:

The Anderson process was originally made for the EP-2 print process as a means of increasing the contrast and color saturation of a print. It involved rehalogenating the image and redeveloping under room light. It was based on the fact that there are unused dye couplers in the emulsion. From reports this can also be used with RA-4 materials. If the method works on a print it should work on a negative.

 

[Domin]

Did you read http://www.kodak.com/global/en/consumer/products/pdf/ae31.pdf ? There is a section describing redevelopment of color material developed accidentaly as b&w. Covers large part of process you described.

Recently I've tried skipping bleach. This is sometimes used in cinematography known as bleach bypass, but from what I found on the web its usually used on some intermediate stock not the orginal neg. I've used kodak gold 200 at nominal speed, color dev then b&w fix. Works, I like the results, but the negative mask seems more dense than normal color neg and has this unbleached looks even in unexposed parts. That suggests there is some silver where we don't want it in the Anderson process.

Anyway I'm going to give it a try as soon as I get c41 bleach and fix.

 

[quiver]

Thanks for the link. But however with bleach bypass; unless the camera was pointed at a black hole there will be silver formed even in the black places of the film. That is to say that there are diffrent shades of black.