May 11, 2010

Caffenol-C-H "highspeed"


Hello coffee junkies,

a new chapter of Caffenol development is ready to be published. I was not satisfied with Caffenol/C and high speed films and I didn't recommend it. Too much fog, flat in contrast, poor usable speed, ugly grain. but I constantly thought of trying to modify Caffenol-C-M for these films. Potassium bromide (KBr) is well known as an anti-fogging agent, but I thought it would mess up the concept of great shadow rendering. I was wrong. So good and bad news: KBr works well with Caffenol, but it is not available in regular supermarkets. In Germany a pharmacy in my neighborhood was able to deliver it within a couple of hours, 100 gramms for 15 Eur. Quite expensive compared to the other ingredients, but it will be good for 100 litres of developer and some hundred films. So the additional coast will be about 4 - 8 Euro-Cent per development. Potassium bromide is not toxic and doesn't spoil the environmental friendly coffee soup.I don't know how easy potassium bromide is available in other countries, reports are welcome. The german name is Kaliumbromid, or you may ask for the scientific latin name "kalium bromatum" in pharmacies.

Crops 10x10 mm negative size, Neopan 1600 @1600 ASA left, HP5+ @ 400-800 ASA right :

So here's Caffenol-C-H, "H" for highspeed, recommended for 400 ASA films and faster. There is considerably less fog, although there will be still some, but not any more disturbing. Tonality, contrast and shadow rendering are amazing for available light with lot of shadow areas. On the minus side we have still quite big grain. For example, the Neopan1600 developed in Diafine produces much nicer grain and was my preferred developer. But I never got better shadow details as with Caffenol-C-H. And I slowly begin to love the bigger grain, together with the wide tonality it gives a special look. Boxspeed or pushing is possible. More detail for exposure index must be evaluated, rating under available light conditions is difficult and I made no densitometric tests. Try boxspeed or +1 push.

How to: I made a stock solution of 10 gramms KBr in 300 ml destilled water, stored in a glass bottle. It will last almost forever. 1 ml contains 0,033 gramms KBr. 250 ml developer need 7.6 or easier 8 ml of the stock solution. This equals 1 gramm per litre KBr. Simply add the 8 ml to the ready mixed 250 ml Caffenol-C-M and voila: Caffenol-C-H. Be sure to do the math right! I'm sorry.

Edit: if still too much fog, use 2 g/l of potassium bromide.

So far I used HP5+ and Neopan1600, both with excellent results. 1gram per liter KBr was added to the Caffenol-C-M recipe, no other changes. Developing time was 15 minutes like before, or 30 minutes stand development with agitation first 30 seconds and 3 minutes presoak in tap water.

Thank you very much Caro and Chris for allowing me to publish the images. Finally an example of the Acros100 in Caffenol-C-H, also works perfectly. But for 100 ASA films I still recommend the simple Caffenol-C-M because the KBr isn't really needed.

Best regards - Reinhold


Acros 100 in Caffenol-C-H, 15x15 mm negative size, the bromide doesn't disturb

28 comments:

sosideways said...

Thank you for developing Caffenol further.

As the other major Caffenol player is seeking compensation for his findings, I admire your approach to share the information free of charge for everyone in the world.

Personally, I feel that taking a lesser known method of doing something and charging people to hear/read about your findings is wrong, thus I will no longer visit the other website.

Keep up the good work!

And THANKS again!

Anonymous said...

Interesting, what you did there, Reinhold. I'm following Stephen Schaubs FR blog for a while, especially what he did with Stand Development and lately with Caffenol. Haven't done any Caffenol development yet myself, but gave stand development a try. Stephen suggested using borax (1/4 teaspoon per litre) in stand development to suppress fog. So I wondered if you have tried this with Caffenol? It's cheaper and maybe this has a positive influence on grain as well?
Keep up the good work.
Christian Wiesel, Hamburg

imagesfrugales said...

Thank you sosideways and Christian for the kind comments.

As far as i read from other sources, Borax and Caffenol will result in much longer developing times and reduced film speed. But with stand development it could be an awarding approach. I encourage anyone interested in Caffenol to do own investigations. Anyone who did this before and wants to share his knowledge?

Cheers - Reinhold

carlos said...

Dear Reinhold! for months I was thinking of developing films again, then I found some people using coffee... well, after 20 years, (and after seeing your results) I'm going back to the lab! Thank you for your inspiring work! coffee rules!

kyle said...

hmmm...I might try this with tmax 400

thanks again

imagesfrugales said...

Hi kyle,

please write again when you did it. Any support is appreciated.

Thank you - Reinhold

Curioblogman said...

Thanks for writing about Caffenol-C, your blog is very interesting!

kyle said...

I just had a thought..

What if you replace the sodium carbonate with borax. Borax is available in health food stores in the US. Its lower contrast and produces finer grain than sodium carbonate. Borax is used in Diafine. Or sodium metaborate which is between the two in contrast and grain.

imagesfrugales said...

Hi kyle,

no bad idea, but needs a lot of adjustments. Very long dev times and my first trials were extremely underdeveloped.

Cheers - Reinhold

Tom Overton said...

Wonderful work here... I don't know if you're interested in the print side of things, but I have done a fair amount of work with Caffenol as a paper developer. Depending on your recipe and the paper involved, Caffenol can do just about anything you want a print developer to do. If you want to read about it, my work (now a couple of years old) is here:
http://sites.google.com/site/tomovertonimages/caffenol
Or if it seems to be going another direction from your work, feel free to ignore this.

imagesfrugales said...

Hello Tom,

I feel honoured by your kind comment. Thank you very much. During my web research I of course came across your highly respected work. I was quite lazy concerning darkroom prints the last couple of months and did a lot of hybrid work, developing film in coffee and improving my scanning skills.

For wet prints I prefer "regular" developers, because of the much longer shelf live, economic reasons and I don't like the brown stain so much for most of my images. But "never say never".

Best regards from Heidelberg/Germany - Reinhold/imagesfrugales

carlos said...

Dear Reinhold,

I used Fujicolor 100, in Caffenol-C, 18min, 20ยบ.

It got surprisingly sharp, but didn't get detail in the shadows. i was not very creative and apologise for using an old camera for subject, such as you, but those numbers are so small and lost into the neg that it realy shows what I mean with "surprisingly".

D200, used for copy the neg, contributed with the grain.

Here is the ink, hope you enjoy.

http://imagio2009.blogspot.com/2010/05/royer-foto-nikon-fm3a-fujicolor-100.html

Chears!

Carlos

imagesfrugales said...

Hi Carlos,

I see some good shadow detail but a massive loss of contrast in the bottom left corner. Strange.

Also regular BW films may be better suitable for high grade photography than CN films.

Best regards - Reinhold

Anonymous said...

Just a thought.. What about using iodized sodium chloride, ordinary table salt, instead of hard to get KBr? Or am i thinking wrong here..

-Magnus

kyle said...

When I get back in to my lab I might try splitting the alkali. So instead of trying borax by itself maybe slightly reduce the sodium carbonate by around 1/8 to start and substitute it with the equivalent strength amount of borax.

Since I wont be able to test this for this for a week or so here is my adjustment If anyone here is feeling lucky.

1 litre water
washing-soda 47.25 gramms
borax 27 gramms
vitamin-C 16 gramms
coffee 40 gramms
bromide soultion 32ml

-Kyle

imagesfrugales said...

I once used 2.5 g/l Borax and got completely blank negs. pH was 9.0. Borax is a very (!) strong buffer and seems to not to work as expected with Coffee and/or VitC. absolutely NO recommendation so far from me. Try at your own risk. If you get usable results anyway, please report.

imagesfrugales said...

Iodized salt may be an alternative. I have no reliable data so far, so try at your own risk. It sometimes seems to work, sometimes fail. KBr works reliable. Cheers - Reinhold

Carlos Zeuxis Paim said...

Hi me and my fellows (we are studying fine arts, more preciselly photography) will test this greate ideia! Thanks so much I guess this (if work)turn photo less expensive, particularly for us in Brazil, and other country in South America!
Thanks again brother!

Anonymous said...

Hi Reinhold,

have you any experience on using caffenol-h as developer for medium-speed films? Becaus i tried it today on a agfa apx 100 and the results are very bad. The film's got almost no blackening, it looks like it has been badly underexposed (which it wasn't). I used 250 mL of standard-type caffenol-c, which worked fine with this film in the past, and added 7.5 mL of a solution of 33.4 g KBr in 1 L of distilled water. Developing time was 16 Minutes.
Cheers

Kai

imagesfrugales said...

Hello Kai, your math is correct for 1g/l KBr, so maybe the "standard" Caffenol-C you used might not work with it. I guess you mean the common 8/4/2/1-recipe and not my Caffenol-C-M? Maybe too much KBr for this weaker recipe.

I don't think that APX100 needs any KBr at all, the results with Caffenol-C-M are brilliant.

Best regards - Reinhold

Anonymous said...

Hello Reinhard,
so here's the recipe for the caffenol-c i use:

250 mL of tap water
2.5 tsp of soda
1/4 tsp of vitamin c
4 tsp of instant coffee.

I admit, it's by far not as mathematically correct as your recipe, but as i said it worked fine with apx 100 in the past. The grain was a bit strong, so i wanted to try it with the KBr additive.
After a bit of re-thinking, i'm quite sure now what went wrong: usually i first dissolve the soda completely, then add the vitamin-c, then the coffee. This time, i mixed all the powders together first and then added the water. Maybe that wrong order made my caffenol not-working.

Cheers

Kai

imagesfrugales said...

Hello Kai,

it is important, in which order you add the things. Always start with the soda, then add the Vit-C. The ascorbic acid must be transformed to ascobate first, CO2-bubbles indicate the process, wait til the bubbles have disappeared. After that ( about 2 minutes), add the coffee. This is a must.

LG Reinhold

Anonymous said...

So then my guess was true: the mistake was the wrong mixing order.
I think i'm going to try caffenol-h again on an apx 100 anyway, just to see if it makes a significant difference or not.
If you're interested, i can let you know the results when they're done.
Thanks for your assistance, keep up your great work!

Best regards

Kai

imagesfrugales said...

Yes Kai, news are always welcome. Thanks, Reinhold

Matt Martin said...

Hi Reinhold,

Thanks for the great blog... Forgive me for the rookie question - I'm just getting started with Caffenol. My first few attempts have resulted in underdeveloped negatives every time. I've tried both the -L and -H versions with pretty much the same results. In both cases, I followed the instructions carefully (measuring carefully with a gram scale) in the Recipe section of the caffenol cookbook. Do you have any suggestions for how to improve underdeveloped negatives? I'm pretty sure its under development as the words along the sides of the negative are barely visible. The film I'm using is fresh Kodak Tri-X exposed at box speed. I'm using Arm & Hammer Super Washing Soda, 100% ascorbic acid, kBr, and Maxwell House instant coffee. Should I try adding more time or changing up the mix? Thanks in advance!

Matt

imagesfrugales said...

Hi Matt, please forgive the delay to answer your question. Sounds like you did everything well. Maybe there's something with your ingredients. Most of the time it's the soda, but A+H should be fine. Hm.... first you should make a heating test of the soda form the water content:
http://caffenol.blogspot.de/2010/03/soda-myth-and-truth_07.html
and
http://caffenol.blogspot.de/2011/02/trouble-shooting.html

If everything is fine you should ask in a forum or the flicktr caffenol group:
https://www.flickr.com/groups/caffinol_private_palace

Analysing a problem via comments here is not the best way. More people may have other ideas.

Good luck.

Matt Martin said...

Since my first comment, I figured out the source of my problem: it's exactly as you say - it was a shortage of soda. I performed the heating test and the AH I have is apparently ~9% water. I increased the soda by 10% and am really happy with the negatives.

Thank you!

imagesfrugales said...

Thank you very much for the update, Matt. Another guy found that his A+H soda had 8 % water, so your results are very close.

For C-C-H it shouldn't be a major problem, but surely for C-C-L. Glad you found the cause - R.