Color negative developer near to C41

[ahock]

Dear Stefan,
I intend to run the same test film at my site. I don't have Jobo test pattern. Do you know any other method to prepare the test film for the color balance test? Thanks!!

Best,
ahock

[newcan1]

Well having tried various unofficial formulations of C-41, most coming up with thin negatives, I tried the "C-27" formula presented here. I don't have a color densitometer or anything, but the negatives came out looking awesome, and they scanned nicely. I have not done any darkroom prints of them yet. But this seems to be a really good formula and delivers negatives of good density at the film's full rated speed. I am excited to see how darkroom prints come out.

[Rudeofus]

First of all, thanks a lot, stefan4u, for posting all this and going through all the effort researching this. Luckily we still get C41/E6/RA4 kits for small scale home users but I wonder when that will change. I would suggest that this ends up in some sticky thread where we collect all these formulations, especially the tested and proven ones. I recommend to all people who want to start experiment that they contact APUG member mts, he has a very fine collection of formulations for C41/E6/RA4, which should at least provide a starting point for optimizations.

Could someone more knowledgeable than me add the following info here?

• Full official names of the chemical compounds listed, also possible ways of obtaining them.
• Toxicity information about these chemicals, safe handling procedures. This has already been discussed here.
• Possibly some info about longevity of the compounds and possible storage recommendations. I'm not sure whether CD4 has other uses beyond color film development and how easy it is to synthesize.

Remember that this kind of work is more important than all the dreading over film discontinuation. We (at least the hobbyists) can easily stock live time supplies of our favorite film stock in a freezer but all this won't help us if we suddenly lose access to dev process, ask the Kodachrome lovers here.

PS: Here is my minimal contribution:

• CD4's official name is "4-(N-Ethyl-N-2-hydroxyethyl)-2-methylphenylenediamine sulfate", CAS number 25646-77-9
• HAS is "Hydroxylamine sulfate", CAS number 10039-54-0

[Mike Wilde]

Well ,some of the challenges to mixing at home depend on getting the chemistry. The Formulary stocks HAS, but cannot mail it outside of the US.

I have a good stock of CD-4, which they can mail me. It is nothing to dream about fabricating at home.

Read up on the history of a dye maker, that a few years ago, shut down in Buffalo NY. I saw the ongoing demolition and clean up efforts as a part of a trip there last weekend.

It went by a series of names in the almost 100 years it operated. The longest lived name I think was National Analine. Its final name was Buffalo Color.
The steps to fabricate some of the dyes, as well as the feedstock volatility and flamability issues are mind boggling. To think that a lot of this was worked out by the 1920's has amazed me.

With color photography what we essentially are doing is splitting the dye so that the second half is the oxidation component of the color developing agent.