Rodinal + catechol?

[ruilourosa]

anyone tryed this? at what quantity?

increased acutance? good stain? increased activity?

i am about to try but it would be nice to hear experiences

thanks

 

[pentaxuser]

A new combination on me. What recipe will you be following and what is your expected results?


Thanks

pentaxuser

 

[ruilourosa]

Going to start with 1gr a liter of rodinal 1+50... but this may not be the correct proportion to the best effect.

i do not know any developer combining paraminophenol and catechol but agfa atomal combined catechol with N-hydroxyethyl-o-aminophenol and hidroquinone in high sulfite solution.

i am just wandering and maybe this combination wasnt used before because it sucks, but let´s see

 

[Paul Howell]

Interesting experiment, as Catechol is a little on the expensive side as Rodinal is a one and done developer, wonder how it will cost out? Also what film speed?

 

[Alan Johnson]

Pyrocat-P contains catechol and p-aminophenol but some calculation or experimentation would be needed to see if simply adding catechol to proprietary Rodinal would make a staining/non staining developer.
https://www.photrio.com/forum/threads/pyrocat-p-pyrocat-m.16994/

 

[ruilourosa]

looking at pyrocat-p seems 1 gr a lot of catechol in my future experiment...

 

[ruilourosa]

Interesting experiment, as Catechol is a little on the expensive side as Rodinal is a one and done developer, wonder how it will cost out? Also what film speed?

i have like 1kg of german catechol i bought a few years ago...

 

[john_s]

i have like 1kg of german catechol i bought a few years ago...

Has it discolored after those years?

 

[Raghu Kuvempunagar]

Have you tried developing partly in Rodinal and completing in a Catechol developer like Obsidian Aqua (or vice versa)? Does that give you additional control on grain and stain, say, by varying the time spent in either of the developers? Or is it an outright bad idea?

 

[ruilourosa]

I read about those 2 developer a few years ago... I tryed something like hc110+perceptol but i found the results nothing special... But maybe it could be another way..., Specially with staining devs.

Another way can be bleach and redevelop with staining developer, this was already tryed, i think.

 

[ruilourosa]

Has it discolored after those years?

My catechol is not a whitish powder but some white brownish flakes. I bought it around 2007 and have not changed in a lab grade brown flask.

I use 1976 metol with no issues...

 

[Lachlan Young]

It'll more than likely have been tried & likely found to offer no improvements over MQ or PQ under meaningful test conditions. Don't associate absence with lack of research, but consider that it was probably tried & was a failure.

 

[ruilourosa]

Tryed 0,05gr in 1+50 (510ml) but no stain in kentmere 100... Activity increased though.
Next time im going to add 0,5 grams....