c41 chemistry for color reversal

Hi all,

I have c41 solutions made up and i want to get some reversal film to project to see how a camera is behaving.

So, I was thinking in:

1. BW develop (D19)
2. Re-expose (in light)
3. Color develop (C41 color developer)
4. Paraformaldehide???
5. Blix (c41)

what do you think?

many thanks!

Colour developer agent issues

The theory isn't too far out of whack, but a few isues - reversal film (E6) usaully uses cd-3 as its developing agent. C41 uses CD-4, so if E6 film is processed this way, there will be a different colour gamut that results, since the oxidization products, and hecne the dyes formed from cd-3 vs cd-4 are different.

If you want reversal of tones, and use c-41 throughout, then the usual route of dev, stop, blix, (or, as I do, dev, stop, rinse, bleach, rince, fix, wash, final formaldeyde containing photo flo wetting bath) should work.

I would recommend a stop step after the first developer, and then a rinse if you plan on doing the reversal step optically, as opposed to chemically. Thie should keep too much first developing agent from being carried into the clour developer.

there's a proscess that i saw somewhere i think its called maximization thats similar to the one you have listed, except I think it went b/w develop, c-41 fix, expose to light c-41 develop, expose to light, c-41 entire proscess?

Why use paraformaldehyde?

If for stabilization, it is in the wrong place. It should be last with photo flo. However, the newer E6 and C41 films don't use it. They use another stabilzer.

PE

hi PE, the PF is for prehardening, i believe it's required for old ektachrome commercial film (motion pic), at least I've heard. Also, I had a lot of reticulation once i tried without prehardening. cheers

At 38 deg C, there should be no need for hardening for either C41 or E6 films. VNF (positive films for cine reversal) have formulas published on the EK web site.

A prehardener should come before the entire process in any case. And, it should be followed by a neutralizer in color processes in order to prevent degradation of the color images.

PE

Tried doing reversal processing with C41 developer years ago, as an emergency measure. No labs were open for the weekend, and I had to produce slides for a Sunday evening presentation. Film was Fujichrome Provia 100.

For the first developer, I used D-72/Dektol 1+1, with some hydroxide and a bit of hypo added. Don't have the exact amounts now, but I do remember that these were the only things added to otherwise normal D72.

Followed by an intensive water rinse (so that no developer is left active enough to continue developement during 2nd exposure).

2nd exposure was done by unreeling the film and coiling it loosely in a large white basin with enough water to cover the film. The exposure came from a 100 watt lamp suspended half a metre from the basin. Exposure was about 5 or so minutes. The water prevented the film from heating up or drying.

Then the usual C41 process steps followed.

At the end, I got acceptable looking slides. Colours were not exactly what you'd get from proper E6 processing, with the greens slightly more pronounced (but no green cast). Saturation a bit low, and hues somewhat muted. But they were good enough to be used for presentation.

As PE said, no hardening was necessary. I would have used some formaldehyde stabiliser, but didn't have this available at that time.

Jay

...I also wonder if the colours would come better had I used colour print developer instead of C41 developer? The consideration here is the CD3 vs CD4 issue.

Jay

Jay;

CD3 vs CD4 is an issue, of course, but also the pH of the E6 color developer is very high to allow development to completion. It also contains some ingredients to allow some silver solvation to take place to enhance dmax. So, the color saturation is kicked up by having a very active developer which C41 developer is not (by comparison).

PE

i am trying it just now and will post the result. sorry about the order (the PF was indeed the 1st step... now i saw my mistake). the thing with the hardening is that i am using ektachrome commercial film (way before VNF appeared). Cheers.

Photo Engineer said:

At 38 deg C, there should be no need for hardening for either C41 or E6 films. VNF (positive films for cine reversal) have formulas published on the EK web site.
<snip>....
PE

Click to expand...

Could you supply a URL please? I have been mousing around on that site but it is such a maze I could be there for a week and not locate what you are talking about.

Pete;

I don't have the URL at hand, but will try to recover it. VNF is the key word to search for in the mean time.

PE