Caffenol-C-M Underdevelopment Troubleshooting
So I just tried Reinhold's Caffenol-C-M recipe (http://caffenol.blogspot.com/search/label/recipe) for the first time. My negatives appear really underdeveloped, and I'd appreciate any assistance in identifying where I screwed up. :-D
The film was Neopan Acros in 120 exposed at 100 ISO in open shade.
Development was 15 minutes at 19-20 C.
-- Gentle agitation for 30 seconds during first minute.
-- Gentle agitation for 5-10 seconds every minute thereafter.
1 minute cold tap water stop bath.
5 minutes Photographers' Formulary TF-5 fix.
5 minutes cold tap water wash.
I mixed the Caffenol-C-M as follows, in the order that follows:
-- 1000ml distilled water at ~35 C
-- 54g Arm & Hammer "Super Washing Soda"
-- 16g Anhydrous Citric Acid from the Photographers' Formulary (from a new, sealed bottle)
-- 40g Valutime Instant Coffee: Original Roast. ("100% Coffee")
(All dry ingredients were measured with an inexpensive digital scale that purported to have 0.1g precision.)
The citric acid foamed like crazy when I added it to the solution, but I waited until it was clear of bubbles before adding the instant coffee. I may not have waited long enough for all microbubbles to dissipate, but there were no obvious bubbles in the solution.
After mixing the developer, I put it in an ice bath to bring it down to 20 C before using it to develop my film. It may have dipped to 19 C (or even slightly lower) over the course of the 15 minute development; I was working in a cold garage.
After searching through other Caffenol-C-M help requests, I thought that my Arm & Hammer super washing soda might not have been water free. So, this morning, I heated it up in my oven in a glass beaker to find out.
Original Sample Weight: 136.5g
After 1 Hour at 170F: 136g
(At this point, I decided to move the heated washing soda powder to a small dish to try to increase the surface area exposed to heat, to see whether that would make a difference.)
After 2 Hours at 170F: 134.7g
So, after 2 hours at 170F, the washing soda has lost less than 2% water weight. I'm comfortable saying that I used "waterfree" washing soda. I wasn't using super rigorous lab technique or great instruments for my single sample analysis, but I'm pretty darn sure that the ingredient I used wasn't monohydrate or decahydrate washing soda.
So, at this point, I think that there might be three potential errors that affected my development:
1. My instant coffee didn't have enough caffeic acid.
2. I didn't wait long enough after adding the fizzing anhydrous citric acid before adding the coffee.
3. I either didn't agitate vigorously enough or my development temperature fell well below 20 C without me noticing.
The negatives, including frame numbers, are very faint. I was able to pull an image out of them (attached), but the histogram I've attached shows how thin the image is.
Thanks in advance for any assistance!
Pat (Caffenol-C-M Test) by Cuckoo Wasp, on Flickr
Caffenol-C-M-Histogram by Cuckoo Wasp, on Flickr