Rodinal in the cold
It's that time of year again that temperatures drop on the northern bit of the globe.
Chilly out, but not cold enough yet to put the heating on.
I'm about to try stand development in Rodinal. But am not planning to keep checking and running back and forth refreshing a warm water bath to keep the temperature up for the duration. Room temperature will be about 14 degrees C.
So how low, temperaturewise, can you go with Rodinal? Are there figures about that anywhere?
Steel tank? Stick it on top of your computer case if youve got a desktop.
That's what I do with my bottles of fermenting sugar, let the bottles touch the side of the case, keeps them warmish in Melbourne weather. They're plastic and it works very well, but they're thin plastic, not sure how it'd be for a thick plastic dev tank.
There's a german guy who has experimented with Rodinal in cold temperatures, I just cannot find his website at the moment. Basically his findings are positive as far as I can remember. Compared to 20C you calculate your time x 1.3 for two degrees and x 1.6 for four degrees lower temperature. This is for a normal agitation method.
For stand development I think 14C is all right. I would whirl the tank every 30min though.
Plastic tanks. Maybe that still helps though.
My laptop computer is a regular toasting oven (a few years ago, a dermatologist from our local hospital published a paper about how the long forgotten phenomenon of erythema ab igne, a.k.a. toasted skin syndrome, - not uncommon when people still had to sit close to fires and stoves to keep them warm in winter - had made an unexpected return thanks to laptop computers), so maybe if i turn it upside down and put the tank on it?
Thanks for the suggestion.
14 C would be o.k.?
I understand the idea is to exhaust the developer, leaving oxidated developer (and what not) in the emulsion to shield against overdevelopment? If so, perhaps i should just let it sit for an hour extra (was planning to have it - HP5+ - sit for 1 hour in 1:50 diluted Rodinal).
Rodinal is a single developing agent p-aminophenol
This is my collection of developing agent temperature coefficients so far:
Ratio of increase in development time that occurs when the temp. is increased 10C.
Temperature coefficient = T1/T2
When the developer contains two developing agents, the coefficient is useful over a limited range.
(Basic photographic materials and processes-Stroebel, Current, Zakia)
Mees & James
Multi developer coefficient's (i.e. MQ) work only over a range of temps. I don't have the limits, sorry.
I think you meant this one:
(in German only)
Lowest temperature there is 16 C.
Hope this helps!
Mono, thanks, that is the one I was after. I tried Rodinal 1+50 once in 16C and was quite happy with the results but the negative side of things is that the development time grows to 20min range. One example is here: http://is.gd/ewgK3 .
I haven't tested with 1+25 dilution but I might do that some day.
For stand development in Rodinal 1+100 I still think 14C is doable. The developer will be exhausted which is the main idea, but it just takes some more time. What's really important here is that the outside temperature is about the same with the temperature in the tank so the liquid doesn't move and create uneven skies or stripes so typical for the stand development.
Rodinal will produce less grain with a lower temperature. But high diluted Rodinal > 40-50 minutes is comming to an end.
When going under 15-16 degrees C the developing time in the higher dilutions will be in theory over 1h. So it won't work anymore. Apart from the problem of the rest of your process, fixing on those low temperatures will be also very slow.
A good optimum temperature for Rodinal is around 18C-20C.
Why, not having the heating on could turn out to be positively advantages.
The developer will be cold, because the ambient temperature will be that too. So i don't expect any warming up through the tank wall and resulting convection currents in the tank.
Good point about the fixer, though. I'll get that up to 'normal' temperature, and give it a bit longer to work.
If Rodinal is exhausted in 40 - 50 minutes, lower temperatures leading to slower action, why would Rodinal then still be exhausted in 40 - 50 minutes?
I'll try 1:50 for well over an hour, perhaps 2 full hours.
I haven't found it to be exhausted in 40-50 minutes (20c), I've done 1+100 2 hour semi-stand for a very large push on Tri-X, the same results not achievable in 1 hour.