Fuji Hunt C-41 kit, Bleach.

[Daire Quinlan]

Hi, quick question about the chemical makeup of Fuji's bleach in their C-41 kit. It has a hazmat 'Glycolic Acid' on the container, but I guess it also contains some other stuff. The thing is I was under the impression that it was a re-halogenating (sp?) bleach. However I did something last night that didn't work as anticipated if this was the case. I ...

1. Ran some RA4 paper in Ilford MG developer, producing a clear B&W negative image.

2. Fixed the paper in C-41 fix.

3. Bleached the paper in C-41 (Fuji Hunt) bleach

4. Put the paper through the RA4 developer.

Bleaching the paper should have re-halogenated the negative image, and then putting it through the RA4 dev should have then re-developed it and activated the colour couplers, resulting in a colour negative image. However, it didn't. Totally blank. So is the Fuji Hunt C-41 bleach something other than what I imagined originally ?

Thanks, Daire.

 

[nickandre]

Did you...turn on the lights?

 

[Daire Quinlan]

Did you...turn on the lights?

After the B&W dev and wash (which was carried out in complete darkness naturally) , yes. I'm trying to think why this would matter though

Initially I'd put it through the B&W dev for a reversal process. The first sheet I did appeared way underexposed, and it had been shot a stop faster than this one, so I decided to see if I could just bleach it and then re-develop the B&W image with the RA4 developer and get a colour neg out of it.

Should the process not have gone something like ...

Darkness
1. B&W dev (and wash)
Turn on lights (this exposes all the undeveloped halides, but they'll be removed by the fix)
2. C-41 fix (removes all the exposed but undeveloped halides)
3. C-41 bleach (converts exposed and developed silver back into halides)
4. RA4 dev (re-develops the halides and in the process activates the colour couplers, producing a colour negative image)
5. Bleach and fix again to leave only the dye layers.

Or at least that was the theory

 

[RPC]

yes. I'm trying to think why this would matter though

The re-halogenated silver, being light sensitive, has to be exposed to light or it won't develop. At least in theory. But it appears you did that, so don't know why it didn't work.

RPC

 

[Bob-D659]

If what you are attempting is the RA4 reversal process, it has been discussed here quite often, you are complicating it no end by adding fix and bleach steps in the middle, and that won't give you a reversed image either as you are just attempting to redevelop the original exposed silver.

 

[Daire Quinlan]

If what you are attempting is the RA4 reversal process, it has been discussed here quite often, you are complicating it no end by adding fix and bleach steps in the middle, and that won't give you a reversed image either as you are just attempting to redevelop the original exposed silver.

Nope, the first sheet I developed as a reversal process, I've posted in the RA4 reversal experiment thread about that, I'm getting consistently underexposed looking results for some reason, not too sure why.
The second sheet, having already been through the B&W developer and exposed to light, I decided to fix, bleach, and re-develop to try and get a usable negative. Also to check see if my bleach was actually working properly, as I had some suspicions I knew it wasn't going to work as a reversal because it was already a stop under the other one from when I'd shot the two sheets in the first place.

 

[RPC]

It appears you must have used a slide to expose the paper, if you got a b&w negative image. If you are trying to produce a negative color image, why didn't you just run it through the regular RA-4 process?

EDIT: Your last post appeared just before mine; I see now why you tried it.

RPC

 

[Bob-D659]

I wouldn't count on C41 bleach to be only rehalogenating, a post on photo.net alludes to other chemicals in it that remove silver halides.

 

[Photo Engineer]

The C41 bleach destroys the ability to redevelop the image.

It is not a rehal bleach.

PE

 

[Daire Quinlan]

The C41 bleach destroys the ability to redevelop the image.

It is not a rehal bleach.

PE

Ah right, That clears that up so. Thanks