Saturday, August 22, 2015

Good news for caffenolics?

When I started this blog, I intended to find a C-41 developer using common household products like coffee, lemon juice, aspirin or whatsoever.

Of course I was open to several failures before something interesting appeared by chance or by searching. And, at that time, I knew very little about processes and my experiments were more or less dictated by trial-and-error.

But one of the first C-41 alternative developers I tried was this one:
1 tsp sodium carbonate, aka washing soda
4 tsp soluble coffee
10 ml of a 5% solution of CD4, CAS number 25646-77-9
water to make 500 ml
Yes, it worked like regular developer at about 40ºC but 30 minutes time. This is because maybe I used very little CD4, about 1g/l  instead  of the standard 5g/l. Never mind, but I remember the results were not so bad and this stayed in my memory until now.

Then I discovered the room temperature process Dignan 2-bath developer that was promising but it has been a long way until I found a way to improve it in order to get better colors, grain and sharpness. My latest improvement lead to:

Bath A
500 ml water
9 g Sodium Sulfite
1 g Potassium Metabisulfite
11 g CD4
Water to make 1 liter
Bath B
500 ml water
25 g Potassium Carbonate
0,6g Potassium Bromide
Water to make 1 liter.
10 minutes bath A and 15 minutes bath B stirring frequently but gently and it will produce stunning colors and acceptable grain.

But, recently I was discussing C-41 with Reinhold G. and he showed me that one-bath developers also develop at room temperature, it's only a question of more time, I do not need to complicate it with a 2-bath developer. So, I started making one-bath at room temperature. Searching for recipes at the internet I found these:

One special stuff used in C-41 developers is HAS (hydroxilamine sulfate) and it is said to be a stabilizer for the developer. Well, investigating about the paper of HAS in the developer, the most complete answer I found was this one at APUG. It is acidic, a weak B&W developer and a preservative.

Considering that COFFEE is acidic too and a weak B&W developer, adding a preservative like metabisulfte to the formula, could make HAS unnecessary. I would prefer that CD4 could also be replaced with something else but by now, I found no substitute.

Resuming, I prepared following developer:
3 g Potassium Metabisulfite
1,2 g Potassium Bromide
5 g CD4
10 g Coffee
25 g Potassium Carbonate
Water to make 1 liter
 I tried this formula with coffee and without and the formula without is very flat, low saturation, low contrast, unsharp. With coffee I had much better results. Besides, much less post treatment, just accepting automatic adjustments of scanner/software. Without coffee I had to adjust saturation and contrast until a certain point. To get more was almost impossible.

Without coffee

With coffee


Geir said...

Nice result! Is it possible to see more examples of this, and in higher resolution?

Geir said...

Also what was your time and temperature here?

Geir said...

Would it work to use sodium instead of potassium carbonate, you think?

Henrique Sousa said...

Sorry for the delay! For more examples, please take a look to my ipernity page,
I am developing at 20ºC, 20 minutes or more. More time does nothing to the film.

Henrique Sousa said...

Yes, I didn't try yet but if I did I would start with 18g per liter of anhydrous Sodium Carbonate!

Kobe VH said...

Very interesting, what about agitation?

Henrique Sousa said...

Agiattion is as normal C-41, gentle and frequent, to the end may be less frequent. Ideal one shoud have a motorized aggitator like in Jobo to avoid uneven development, IMMO.

Henrique Sousa said...

Unfortunately, this developer has not a long shelf live. Results after one month are already poor.

cafe selavy said...

Are there any updates to this? I am just beginning to research one shot color developers. This is very intriguing.

Henrique Sousa said...

No, I didn't use the formula with coffee again, I only observed that it doesn't last very long, after one month it was exhausted.
Back to my modified Dignan 2-bath with good results.