Caffenol-C-H high concentration test

[elerion]

This thread's purpose is just to share some results I got experimenting with Caffenol-C-H.

I accidentally raised its concentration on one of the many test I'm performing, and I measured how it affected FP4+ and HP5+ versus the original formula.

* I doubled iodined salt.
FP4 fog and darker zones (mainly I to III) got lower in density. This might be due to this ingredient being added as restrainer to lower fog (?). I must note that Caffenol-C-H is targeted to medium/high speed film. But this is a test to check if FP4 and HP5 films can be developed together.

HP5 did not change on the shadows neither fog.

* I increased coffee and ascorbic acid by 20% and sodium carbonate by 12%.
Both films got stronger V to VIII zones. This makes sense, as this formula has increased developing agents and pH.


* Conclusion

This isn't something good, as highlights are already boosted using the original formula, as you can read on this thread

In short, the characteristic curve is way too steep on highlights, and lacks some density on shadows, compared to other common curves by other developers. At least for me.

So, I wouldn't recommend raising any of the ingredients, though I haven't tried doing it individually. Reduced soda Caffenol variant is another reason not too.

If anyone interested on detailed density measurements, just ask, and I'll post them here.

 

[kossi008]

...

* I doubled iodined salt.
FP4 fog and darker zones (mainly I to III) got lower in density.
...
HP5 did not change on the shadows neither fog.
...

I made the same observatrion with Potassium Bromide instead of iodined salt: higher iso films react less sensitively to it.

 

[manculi]

Interesting, I've been testing Caffenol, but C-L and stand development, in pushing some Tri-X over 3 stops and I'm getting a base fog way to high - I know it may be as one may expect. As I can't find potassium bromide, I'm also using iodine salt.
Although the base fog and somehow low density of the films, I'm getting good details both highlights and shadows. At least for scanning, as I do so little wetprinting.

And, as a matter of fact, I've did some tests pushing TRIX 3 stops on Parodinal 1:200 for 2hours and got a little less fog and density - same difference.
I am wondering how can I get this fog lower?
And why don't you test CCL and stand development? It takes me the same one hour to develop Acros 100 and TRIX, both at box speed. I've never developed the both together, but it give me nice shadow detail and may be worth a try.


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