May 2, 2011

some pictures - Caffenol-C-H

Kodak Tmax100 @  EI 400 (image above) and Rollei RPX 100 @ EI 400 ( image below), developed in Caffenol-C-H with 0.5 g/l potassium bromide. 12 minutes @ 23 °C regular agitation, equaling about 15 minures @ 20 °C. EI 200 would have been better for both films.The Tmax additonally was quite underdeveloped. Bought short before the expiring date he was stored in a small shop at probably unsuitable conditions some years without any cooling. During summer that could have been easily much more than 30 °C, the shop has no air condition. Seems he didn't like that too much. Anyway, I like the pic.

Cheers - Reinhold


l42 said...

Hi Reinhold and thank you for your wonderful site.

it must not necessary be the age of the used Negs wich is responsible for the lack of details in the shadows of your pictures. Aged Neg-material tends to get foggy and make up even shaddowdetails that arent really there.

i am using CCH with polypanF since a couple of rolls now and i am experiencing underexposure/ underdevelopment as well. i am using premixed dillutions of Coffee an Soda wich i bring together 1:1 just before use. i store them on the kitchenshelf without any temperaturecontrol. therefore i had to do some developements in higher degrees in the last weeks, when temperetures went high here in Karlsruhe.

what i first thought to be underexposure seems to be a form of underdevelopment. it seems to turn out, that the old rule "plus 1 degreeC equals 10% less processing time" does not really work for Caffenol. actually Caffenol seems to loose strength above 20 degreeC in a way that outperforms the shortenig of processingtime. to get to welldevelopped pictures you then have to use the same time as when processing at 20 degree - and i even got the impression that higher temperatures make as well loose about 1 EV of dynamics, which then (in not too well exposed pictures) seem to be a kind of underexposure.

Did you make any kind of a test to evaluate the best developing temperature for highest contrastrange?

imagesfrugales said...

Hi, I can't verify your findings concerning temperature. I developed the RPX 100 and the Tmax 100 in one batch in the same tank at about 23 °C. The RPX 100 came out as desired and I found that the rule of thumb (1 degree - 10%) is working fine for me.

The RPX 400 f.e. delivers very flat negs at 20 °C but got a real boost of contrast with 24 °C. A film that needs a strong kick in the ass and the 24°C exactly do that.

BTW, not caffein is a developing agent, it's the caffeic acid ;-)

Cheers - Reinhold

vl42 said...

maybe i am wrong with that temperaturething- its just a hobby to me and as long as the pictures of my children get well, i am happy enough.

today i used less KBr -only 0,7gr to the litre CCH- and developped @24 degree again and the negs look quite good but are still in the drying,

maybe the different type of films TMAX an RPX100 have different amounts of Bromide in the emulsion and therefore tend to react diferent to the additional KBr given in CCH?

oh - speaking of caffeic acid- what i still dont understand is, why i want to neutralize the acid by adding alkaline washingsoda and then re-acidize the mix by adding Vitamine C. i tried just coffee and it diddnt develop at all, thats for sure. but why?

oh, btw, coke with washingsoda works as well, if you might be unable to get to instantcoffee. i tried that too, but diddnt really go for a repeatable recipe..

Anonymous said...

Isn't the question rather, how do you meter a scene like this? I'm sure a camera reading is easily fooled by the white building and the bright sky. Or did you read the important shadows and set them to zone 3 (-2 stops from what you read)? Without proper reading the iso increase with cafenol is just guestimation, isn't it?

Regards Christian

imagesfrugales said...

@ Christian: I metered properly regarding the backlight. The whole film was underexposed.
Best - Reinhold

@ vl42: caffeic acid and ascorbic acid (Vit-C) must be neutralized by the alkaline, washing soda here. Almost all developers need an alkalic pH for activity. Adding Vit-C to coffee makes a far better developer. Using coffee alone you also must add soda for activation.

Eing6888 said...

HI! I am back with my work :)
I use CCM to developed my film (100 ACROS). I also used CCM to develop my photo, for photo I kind of guess when it should be taken out of developer. Furthermore I used dilute white vinegar as my stop and I used high concentrated saltwater as my fixer (I mixed aquarium salt with water). All of process are safe for environment and used household chemical.

Thank you so much for help me walk through this process,
Arunwong Opastpongkarn

imagesfrugales said...

Hi Arunwong, if the salt water really should remove the unexposed/undeveloped silver, the used fixer will be as toxic for the environment as regular fixer! But if you use it as a one shot fix, the amount of silver ions is quite low.

But it's always said that salt water doesn't protect the negs from beeing distroyed within some time - be it months or years - don't know.

vl42 said...

just in case, i might need it someday: what concentration of salt ist necesssary to make water become a fixer?

imagesfrugales said...

I tried with a saturated solution of kitchen salt and it didn't clear the film at all, even after 1 hour no effect. I won't follow this item any more.

Anonymous said...

Dear Reinhold,
I start development with CAFFENOL and just caffenol. I don't andersatnd the way to change EI 100 VS EI 200 OR EI 3200. Could you make a procedure like the summary of your reciepies. exple: for EI200 is 13 minutes soaking at x°?
I hav 'nt find the answer of that question in this blog.
"robusta power"

imagesfrugales said...

No, that isn't possible. Development times are dependant from the used film, the choosen exposure index for this film, temperature, agitation and of course the used recipe.

You find a lot of specific data here, for example for Tmax100 and many others. Look under "Labels".

vl42 said...

i tried saturated salt dillusion as well. i dint see any clearing at all afte 20 min. then i lost interest and stopped the experiment.

where does the idea of fixing by NaCl come from? is it necessary to ad an acid?

imagesfrugales said...

As far as I konw it was done in the 19th century before discovering thiosulphate fixers! And now let's do something useful, let's shoot some nice pics.