Caffenol P1

Dear Photo-Forum,
after reading your posts for years without actively taking part I decided to register just to let you know of my latest experiments with Caffenol. It is my go-to developer since years and I usually use the Delta-receipt. Whenever a Push-development is needed I usually use the CM or CH receipt which gives a +2 push dev. Now I tested out wether or not a mixture of these two receipts can give a +1 push development. You can read about my findings and tests on my blog, where I posted a lengthly article about Caffenol P1: https://blog.erdmenger.de/2024/02/05/push-entwicklung-mit-caffenol/
If you don't understand german, I bet G**gle translator can help. Otherwise please ask me to post a sum-up translation here. Thank you!

Regards, Till

Hi Till, welcome aboard and thanks for sharing your interesting blog!

Did you know we have a section dedicated to blogs? https://www.photrio.com/forum/news/ You can submit yours here and (after approval) are included in the list. This might be relevant for you as well, especially if you intend to write more blogs in the future.

Looking forward to your further contributions on the forum!

Hi,

Businessfotos said:

the CM or CH receipt which gives a +2 push dev.

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I think it's important to emphasize that the push is not a consequence of the recipes themselves, but the result of the long developing time (15min) that is given as a starting point. CM/CH can be used for normal or pulled developement just like any other general-purpose developer.

I'm actually right in the middle of an experiment with caffenol CH (rs) and my main film fomapan 100 shot at box speed. The 15min time given in the recipe is WAY too much, and is indeed quite a big push.
But when gradually scaling back the times, things start to look normal. I'm down to 9min right now, and while it's still a bit hot it's getting harder and harder to see the difference with the control strip developed in Adox XT-3 with a tried and true developing time.

npl said:

[…] the push is not a consequence of the recipes themselves, but the result of the long developing time (15min) that is given as a starting point.

Click to expand...

Actually I didn't think about that point either. Sounds reasonable to adjust this hot mix to produce box speed. If you look at the measures the CM/CH has more than double the amount of soda over Delta. Without being a chemist nor talented with stuff like this I assume this is what makes the mixture so hot in pushing the film 2 stops.

Some time ago I tried the other way round and elongated dev time for Delta to compare results with CH. Some old legend says to multiply dev time by 1.2 for 1 stop push. That would be times 1.44 for 2 stops. You can check my results here: https://blog.erdmenger.de/2023/09/01/artlog-architekturfotografie-und-caffenol-push-entwicklung/

If we divide the 15min CM/CH-time by 1.44 we get around 10min for a box speed development with this very receipt. Interesting to see that you even need to down the time to 9min … did you make any comparison with the C-Delta as well?

Regards, Till

Businessfotos said:

Some old legend says to multiply dev time by 1.2 for 1 stop push. That would be times 1.44 for 2 stops.

Click to expand...

That matches my experience. I would note however, that agitation can also affect contrast. One of my standard tricks (with conventional developers like D-23 or Parodinal) is to extend development by 40-50% over "normal" but reduce agitation to every 3rd minute; this gives shadows the boost they'd get with a two stop push, but due to local exhaustion produces near-normal contrast.

I looked up the Delta recipe and read your article, thanks (google translate works .. kinda ). For convenience sake here's a quick chart :

Caffenol recipes for 1000ml



References :

The Delta Recipe and about caffenol in general

When I first started caffenol, there where not so many recipes on the net, I think there where about 3 websites that had some information about caffenol. One of the best ressources at the time for …

www.caffenol.org

Recipes

Welcome everybody, after more than 15000 hits and readers from more than 60 countries in less than 5 months, here's a chart for your conveni...

caffenol.blogspot.com

Rezepte

for my german friends... Don't worry, this blog stays in englisch language. This post is an exeption. Das Bild kann wie alles von mir oh...

caffenol.blogspot.com

Caffenol C-M and C-H (RS/RSA)

Hello coffee (ab)users, I'm very happy to present Eiriks report about his reduced soda/ascorbic-acid versions. Have a nice reading, an...

caffenol.blogspot.com

I guess it's all relative. CCM/H can be considered hot compared to other caffenol recipes like Delta, but it's not as active as, for example, XTOL stock (5-6min for fomapan 100 at box speed). Delta is not much different than CM/CH regarding the quantity of ascorbic acid and instant coffee, but went the route of a significant lowering of sodium carbonate. I guess it lowers the PH below 9 and render the mixture much less active. But why lowering the wasing soda so much while keeping Vit. C (not cheap !) and instant coffee to somewhat high quantities ? the article I've found (see references above) didn't explain much.

In your article (https://blog.erdmenger.de/2023/09/01/artlog-architekturfotografie-und-caffenol-push-entwicklung/) you explain that CM was better than Delta for a 2 stop push, but also note that the extended developement with delta was barely enough. It would be interesting to compare the two recipes using developement times that gives the same density in the highlights.
In the meantime, my working theory is that the caffenol C recipes don't matter much as long as there's enough developing agents and the PH is in a given range (8-10.5 ??) : the same results can probably be achieved tinkering with the quantitites of each components or using the developement time as the only variable.

Businessfotos said:

If we divide the 15min CM/CH-time by 1.44 we get around 10min for a box speed development with this very receipt. Interesting to see that you even need to down the time to 9min …

Click to expand...

Interesting indeed that the 1.44 "rule" applied to CCM/H 15min starting point gives 10min, that's pretty close to where I'm at. As Donal Qualls pointed out, difference in agitation scheme play a role, and I'd add that we all have our personnal preferences regarding how dense we like our negatives. I usually print at what should be a grade 3 on my color head so I'm not a fan of high contrast ones. But this remark encouraged me to try a developement right away with CCH(rs) using real shots, 9min at 20°c : the negatives are drying right now and they look good I'll try a quick scan and maybe a print tomorrow.

Here you have a more complete chart, but for 500 ml (one film) :