Caffenol-C-L stand development

Real stand development with TMax100 as 120 type film. Shot with my 65 years old Bessa 66, vignetting of the first picture caused by filter (old fashioned yellow-green) and lens shade. Coloured with Gimp. First image EI 400, second EI 100, same roll. Click on the images as usual for bigger size.

Recipe as posted before, but only 1 g/l bromide. 5 minutes presoak in tap water, 10 gentle turns at the beginning, then let stand without further agitation. 60 minutes at 22 °C. Stop, fix and rinse as usual.

BTW, C-C-L has a pH of about 9.0

Perfect transparent film base, no fog, very little yellowish stain from the coffee. Usable on the same roll from EI  50 to EI 800.Scans very easy and surely will print at EI 200 - 400. For wetprints from EI 100 and below you should reduce dev time, otherwise negs become very dense, but no blown highlights!

My best Caffenol so far.

I love coffee - Reinhold

Caffenol-C-L + high speed film

Recipe and semi-stand development as in former post. 50 minutes at 22 °C. Remember to adjust dev times as usual for differing temperatures.

Neopan 1600 exposed at about EI 1600, difficult to tell with night photography. I'm confident to gain real 3200 with longer development.

Shot with a 35mm SLR and very cheap telezoom lens. Crop 10x10 mm negative size

Caffenol-C-L is a breakthrough with high speed film imho. Very low fog level, sharp, nice and small grain for 1600, very wide tonal range, perfect even development.

I love coffee - Reinhold

perfect development with Caffenol-C-L

2 posts belowyou can see the effects of different agitation. From extreme uneven development with stand development to a dramatic improvement with standard agitation. 

When adding the restrainer potassium bromide (KBr), we see perfect even develpment up to the reel covered borders - even with minimal agitation as shown here. With intension I made no proper black adjustment here to show the improvement in the clearest possible way. 

So here's my recommendation:

If you are satisfied with "regular" Caffenol-C like C-C-M, be happy. If you experiance uneven development, agitate more (you will have to adjust developing time). If still not satisfied use Caffenol-C-L. 

The benefit of C-C-L besides the 100% perfect even development are reduced grain and almost fog free negatives.

Caffenol-C-L will be my standard in the future.  My 100 g box of potassium bromide will last for a couple of films ;-) Caffenol-C-M will still be my standard as an easy to use and easy to get developer with enhanced film speed..

 So if you can get KBr for a resonable price in your country, buy it! You won't be disappointed.

Cheers - Reinhold

Caffenol-C-L

First results, Minolta X-300, 50mm Rokkor, orange filter, APX 100 in Caffenol-C-L

Recipe:

16 g/l washing soda waterfree, 10 g/l Vitamin-C, 40 g/l instant coffee, 1,5 g/l potassium bromide (KBr)

Use 1 - 2 gram/liter KBr, 1,5 seems to be a good idea. Do not use more than 2 g/l, it will restrain development too much up to blank negs.

40 minutes semi-stand development at 24 °C. Agitation first minute continuos, 3 inversions each at 2, 4 and 8 minutes, then let stand.

No fog, fine grain, perfect even development, about boxspeed.

Maybe some minor tweaks in the future, but looks fine so far. 

Maybe not everybody is able to get potassium bromide easily? I got it from my next door pharmacy. It's not toxic and environmentally safe with the used quantities.

Looks promising that C-C-L may also be good for high speed films.

Do not try (semi-)stand development without a restrainer like KBr -> agitation is the key! 

PS: I didn't use semi-stand development for another reason than comfort, I don't like shaking for half an hour. ;-)

Cheers - Reinhold

uneven development

 click on the picture for bigger size

 Some people report uneven development and/or disturbing fog. That effect appears almost always with classic (cubic crystals) emusions like Ilford PanF+ or Agfa APX 100. Not enough agitation is the cause. A drastic example is stand development with Caffenol-C, as you can see in the image above.

What is happening? Lets regard the left picture. Stand development makes it visible. Classic bw-emulsions contain a lot of silver-bromide, the silver is reduced by the developer to form the blacks, and the bromide is set free. Bromide is a strong restrainer, but without or too less agitation it sinks down in the tank and produces less development, marked with a red "x" in the left picture.Also below parts of high exposure more bromide is set free and causes streaks. Below the sprocket holes, less bromide is set free leading to stronger development. Finally the bromide accumulates at the bottom and there we find the least development and - the least fog!

In the right picture with regular agitation we see no eneven development or fog at all exept for the small upper and lower parts covered by the reel during development. The bromide is dispersed evenly and so we have a constant restraing effect over the whole area. The uncovered upper and lower borders are developed evenly  with low fog level, see the red "x"-es.

So agitation is the key for even development. Of course there is some remaining general fog,  but doesn't disturb because it is spread evenly over the whole film. If you get uneven development or disturbing fog, agitate more! Try the heavy agitation regime recommended f.e. for Xtol, 5 times in 5 seconds every 30 seconds. That's almost shaking! And reduce dev time when doing this! Time, temperature and agitation are closely related, keep that in mind always.

My trial with stand development was very revealing. It was done when experimenting with low-pH Caffenol-C. As the development times with low-pH will increase and I didn't want to shake the tank for 20 or 30 minutes, I gave stand development a try. With the shown faults. But - when adding the bromide in a good amount from the beginning as a separate agent, unevenness and fog will be gone! So stay tuned and await a new Caffenol-developer by me, it will be named Caffenol-C-L. Only a little bit of fine tuning necessary.  Compared to C-C-M it will have a bit film speed loss, but probably still boxspeed, finer grain and fog free even with stand development!

With "modern" medium speed films like Acros100 or Tmax100 things are different. They contain much less bromide and are much less fog sensitive and show perfect even development with C-C-M. Maybe C-C-L will also be recommended for high-speed films. So some things to do in the future, it doesn't get boring at all.

Time for a cup of coffee - cheers - Reinhold

3200

Fuji Neopan 1600 @ 3200, Caffenol-C-H. First trials @ 1600 showed that there is still some headroom for underexposure. Yep.

my dream team

Pentacon Six 6x6 SLR, Carl-Zeiss-Jena Sonnar 2.8/180, Fuji Acros100 EI 200, exposure f5.6/250 handheld, Caffenol-C-M, 24 °C, 10 minutes, crop 10x10 mm negative size.

The 25 MP scan (3 MB filesize) can be seen here:   http://img126.imagevenue.com

The scan was done as always with a modest Canoscan 8800F. With a professional print service or a good enlarger you can make huge, wall-sized prints.

Cheers - Reinhold

Who invented coffee based development?

When asking myself who invented Caffenol, I stumbled across an article by Dr. Scott A. Williams Ph.D., Rochester Institute of Technologie (R.I.T.). The Technical Photography 1995 Class under the leadership of Dr. Williams should research non traditional developers based on household ingredients and after some unsuccessful trials they decided to test drinks with caffeine like tea or coffee. Coffee was the winner and that was the beginning of coffee based developing. They used baking soda and potassium hydroxide for buffering the pH of 9. The name Caffenol wasn't yet created. We now use the more conveniant washing soda as pH adjusting agent, and the later addition of Vitamin-C since about the year 2000 improves the image quality dramatically. If you want to read the whole article, look here: http://people.rit.edu/andpph/text-coffee.html

The article is pure text without images, but refers to images that once must have been attached. I searched the web to find the lost images, but couldn't find them. So I decided to contact Dr. Williams via email and he sent me the original article, published in "Darkroom and Creative Camera Techniques", issue Sept/Okt 1995, with the kind permission to publish the images here on my blog. I don't want to bore you with scientific figures of molecular structures, but I'm pretty sure that you are curious who the people were and looked like. So here we go:

THE INVENTORS OF COFFEE BASED DEVELOPMENT:

You deserve our highest appreciation

Thank you so much. Best regards - Reinhold

next summary

Hello again everybody,

the blog develops more and more, thanks to anyone who contributed with submissions and comments. More than 5000 hits and 70 comments in less than 2 months, wow! That's much more than I ever expected. Good to see that so many people are interested into coffee development and film based photography in general. Analogue photography becomes again more and more respected after a long suffering time, gently ridiculed. Self-confident again we enjoy our passion.

There are many ways to become happy with coffee development. My way is to prove that coffee and Vitamin-C can deliver the best of the best. Therefore only recipes I'm convinced of myself will be published here. The best overall way is still Caffenol-C-M as a speed enhancing developer with medium speed films of 100 ASA in my opinion. Easy to use with great and very predictable results. Other recipes and more experimental kinds of developing are frequently discussed at the caffenol group of flickr. A great ressource you shouldn't miss with many highly respected members participating.

It's just a beginning - cheers - love and peace - Reinhold

Tmax100 @ EI 200, Caffenol-C-M, 65 years old Voigtlander Bessa 66 with Skopar lens and yellow filter (2x)

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