Home made C41

[Sarbajoy Paul]

Hi, I am a new member here.
I wish to make home made C41 chemistry. I am from India, and here, the supply of C41 chemistry is very inconsistent. I found a link, which gives out a formula, has anyone tried this? Or, if anyone has a suitable formula, please let me know.

https://www.bonavolta.ch/hobby/en/photo/c41_ra4_chemicals.htm

Processing labs are not good here, none of them maintain standards. Last time I got myself some unicolor kit, which is not available any more.

Regards
Sarbajoy paul

 

[Donald Qualls]

Do you have a supply of CD-4? Substituting another color developer won't work as well.

 

[Sarbajoy Paul]

Hi. Yes, I do can procure the individual chemicals, that's not an issue. The only issue is a decent formula. Since these chemicals are very specific and very expensive, I want to communicate with someone who has done it in the first hand.

 

[koraks]

Yes, I've worked with the Bonavolta formula fairly extensively. I've processed dozens of rolls of film with it and I've also translated the formula into a 2-part concentrate that can be mixed with water and to which the appropriate amount of CD4 can be added just before use.

Overall it worked quite OK, but the results were a little less in terms of quality than official C41 chemistry. If you're very serious about quality and intend to optically print your negatives onto RA4 paper, I think it's a good idea to see if you can get your hands on e.g. Fuji minilab chemistry.

Elsewhere on this forum you can also find some additional formulas, e.g.:

• Some formulas posted by Stefan4U based on his own research & experimentation: https://www.photrio.com/forum/threads/color-negative-developer-near-to-c41.42731/
• Some formulas posted by PhotoEngineer that are supposed to be close to 'official' formulas: https://www.photrio.com/forum/threads/c41-formulas.142062/

As you can see, the 2 sets of formulas listed above are quite close. I did a direct comparison between Stefan4u's C27 and C29 formula and compared that to the Bonavolta chemistry. I found only marginal differences that were not meaningful in practice, suggesting that they more or less worked the same, at least on the film I used for testing. Perhaps C27 had the slightest edge over the other two options. Proper Fuji developer performed the best with visible differences with the homebrew stuff I tried.

As Donald mentions above: you need CD4. You may be able to get away without using hydroxylamine sulfate (HAS) if you use the developer immediately after mixing and discard after use.

 

[Raghu Kuvempunagar]

@Sarbajoy Paul: welcome to photrio!

@Photo Engineer who was a scientist at Kodak and a fountain of knowledge on photrio had posted these formulas: https://www.photrio.com/forum/threads/c41-formulas.142062/

You might want to look at them.

 

[cmacd123]

I recall using the Zone V C-41 formulas when they were new. Dale Nevell published them with Teaspoon measures. He was never quite satisfied at how the bleach worked with ECN2 film. The film I developed way back when was "close enough" to be scanned last year. CD4 was apparently selected as it seemed to be "less toxic" than the correct developing agent.

Back then you could take your used developer, dilute it was water and add some benzyl alcohol and develop EP2 Print paper. which unfortunately is long gone from the market.

 

[RPC]

I have tried the developer formula posted by Photo Engineer and the results were indistinguishable from Kodak C-41 developer, comparing sensitometric results. In fact PE himself has stated that that formula is almost identical to the official Kodak formula (which is proprietary). If you mix it with distilled water you don't need the diethylenetriaminepentaacetic acid pentasodium salt.

I have also used the simpler Bonavolta formula but you should measure the pH and adjust it to 10.0-10.2. When I mixed it, I found it was a bit high before adjustment. YMMV. Results were close to PE's formula.

You may be able to get away without using hydroxylamine sulfate (HAS) if you use the developer immediately after mixing and discard after use.

I tried this with the Bonavolta formula and got good sensitometric results if the pH was adjusted to 10.0-10.2. There is enough sulfite in the formula that it can last for weeks even without the HAS.

 

[koraks]

I have also used the simpler Bonavolta formula but you should measure the pH and adjust it to 10.0-10.2

Yes, that's right, I forgot to mention it. It requires pH adjustment to around 10.20 in my experience or even 10.25.

 

[Raghu Kuvempunagar]

You may be able to get away without using hydroxylamine sulfate (HAS) if you use the developer immediately after mixing and discard after use.

If you mix it with distilled water you don't need the diethylenetriaminepentaacetic acid pentasodium salt.

Both of these chemicals are available in India and not too expensive. CD4 is unfortunately not available locally AFAIK and has to be sourced from outside.

 

[koraks]

CD4 is unfortunately not available locally AFAIK and has to be sourced from outside.

It can be sourced from China, but usually in amounts starting at 1kg.

 

[Raghu Kuvempunagar]

It can be sourced from China, but usually in amounts starting at 1kg.

That's true. At times importing chemicals for personal use can get a bit problematic with customs. To avoid unnecessary hassles, OP should ask local chemical lab if they can procure it for him from China.

 

[koraks]

OP should ask local chemical lab if they can procure it for him from China.

In that case, I'd strongly suggest simply asking to buy some C41 chemistry...

 

[Raghu Kuvempunagar]

In that case, I'd strongly suggest simply asking to buy some C41 chemistry...

Sourcing CD-4 from China and buying other chemicals in India can work out a lot cheaper than importing C41 chemistry from Europe.

 

[koraks]

Yes, I can imagine that and it could be a factor.