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I've just started using rodinal. I know that it's better to use it at lower temps than d-76. I've heard 65-68 degrees is best. If I'm usually doing 50+1 and 13 minutes at 68, should I change the time at all if I drop the temp? I'm using 120 film if that matters at all.
The short answer is yes, the lower the temp, the longer the time. Why lower it though? Rodinal is fine to use @ 68f.
I too have read that Rodinal performs better at lower temps -- something to do with graininess or something as I (vaguely) recall. So maybe (not 100% sure about this, I'd need to do some tests) with higher temps you get more graininess than with lower temps (while adjusting the time of course). Then again, you're shooting 120 roll film so graininess shouldn't be that much of a problem. To be on the safe side, perhaps try to keep the temp at or slightly below 68°F (20°Celsius).
Which film are you using?. If you're really worried about grain, perhaps Rodinal is not for you. I use it because it's so conveneint, and it has nice grain (to me anyway, sort of salt an pepperish). With 120 you'll get away with the grain issue a little easier.
APX 100 + Rodinal in 35mm is gorgeous (to me, but everyone's different). My regular brew is TriX in 120 + Rodinal at 68 degrees.
If you want to pursue this further, I suggest you visit the photo.net site and type in Chris Waller (from memory) and Rodinal. I've read many of his posts and he has used Rodinal in many different ways. Roger Hicks lurks there as well, and I think he has suggested adding somthing to the rodinal to keep the grain down, I've never tried it, so I can't rememeber the details.
With rergard to temperature, there may be some difference, however it is probably marginal
If you cool down from 68 to 65F you may have to add 15-20% time to your development time.
Look in the Ilford webiste for time/temperature pdf (works for most fil/dev combos)
It's been said that Rodinal works best at 65F (I maybe one of the culprits in expanding that) but I was just rading last night an old article in PhotoTechniques in which they debunked that myth.
So I'll try to get a more quantitative opinion by just developing 1/2 of a roll at low temp and the other at higher temp (65 and 75 F) and see if there is any dufference in grain/tonality
I'll use EFKE KB100 and Rodinal 1+50 for both tests.
I believe (with real proof) that dilution is more important than temperature control in Rodinal. The more diluted it gets, the smaller the grain, the longer the tonal scale and the sharpest the pictures.
I'm looking forward to your test results. Just for the record, I don't have any proof that Rodinal would produce grainier results at higher temps, it's just something I came across recently on some forum (and frankly, it surprised me) (probably photonet). I would also think that dilution is more important than temp.
Just a question though; with the developers I often use these days (eg Xtol and D76), the more diluted it goes, the grainier the results tend to be. So you're saying that with Rodinal higher dilution reduces graininess? Well, could be, I've never really done any comparisons (I always used 1+50)
Rodinal in that is a strange animal.
It is a very simple developer, one dev agent, alkali and preservative. No sulfite as a solvent for silver.
It is then that the advantages occur, more dilution means "gentler" development, more compensation if you agitate less and less grain.
I think the article in unblinking eye can be far more descriptive that I'll ever be:
PS The Rodinal + Vitamin C proposed in there works great!!!
1+100+C is fantastic with JC Pro 100 and EFKE 100
titrisol has it right: 'normal' developers like ID11 have sulfite, which eats away a bit of the silver grains - thus making them smaller; when you dilute those developers, there's less sulfite per silver grains, so less 'eating-away' -> coarser grain.
Rodinal does not have anything that reduces grain size (that's why it is inherently grainier - but also sharper - working); when you dilute it more, it will be less active, and therefore develop finer/smaller grains; samer for temperature: lower temperature = less activity = finer grain, even if you have to compensate with longer times (at least in theory - I have not done any comparison tests, but there's a lot of authors that say Rodinal is best used below 20°C/68°C).
I have to say that I'm still a bit mystified as to why Rodinal would perform any better at sub-68f temperatures.
Lower temp = less activity = smaller grain, true, but it also = lower contrast. You compensate for that by developing longer, which gives you -ultimately- more activity, which results in larger grain, and you're back where you started.
I've always thought that time and temperature were just two different ways of achieving the same end, control of contrast, and could always be balanced off against each other. Needless to say, I too will be interested in titrisol's tests.
Well, it is said that the reason is that if you develop rather quickly, with a more aggressive developer (ie. a warmer one), grain will be larger, even if you compansate for contrast and devlop longer with a gentler (colder) dveloper - same thing with dilutions, where Rodinal 1+25 is supposed to give larger grain than 1+50 - even if you have to develop longer in the thinner mix, for similar contrast; I guess it depends on the way the crystals are devloped, but this is only hearsy, I haven't done any comparison myself.
Well, it is said that the reason is that if you develop rather quickly, with a more aggressive developer (ie. a warmer one), grain will be larger, even if you compansate for contrast and devlop longer with a gentler (colder) dveloper - same thing with dilutions, where Rodinal 1+25 is supposed to give larger grain than 1+50 - even if you have to develop longer in the thinner mix, for similar contrast...
Interesting. I've learned that in Rodinal, grain doesn't increase with dilution, and may even improve. So there is one rule-of-thumb gone.
I'm beginning to see why some photographers are therefor using it in ultra-high dilutions (greater than 1:100), no agitation, with resulting development times measured in hours (I'm curious to try this myself as I have a lot of Pan-F to play with). Perhaps at these dilutions, there's a benefit to slowing development even further (by using cooler developer) which wouldn't be noticeable at 1:25.
Just out of interest, I looked up some info on Kodak's "Arctic" developers, D-82+Caustic, and SD-22. The latter is an Amidol-Catechol formula which, when diluted with Ethylene-Glycol, can be used at temperatures down to negative 40f. :eek:
Anyway, think I'll make a cup of coffee and read through that link to the unblinkingeye article on rodinal.
Well, I was so intrigued that I thought I'd do a little test myself (I hope titrisol will also post his results and/or comment on mine). This is a first series of tests using APX 100 and Rodinal at different temps and dilutions. FWIW, here are some results (sorry, long post ahead).
I shot three series of each five shots of the same subject under the same lighting conditions (overcast, light was stable during shoot which took about only 5 minutes or so). Bracketing was used: +1 stop, +1/2 stop, +-0, -1/2, -1. Light measured with spot meter on grey card (zone V), white wall (zone VII), and a dark hedge (zone III). (I placed the hedge on zone III and the rest fell in the zones as indicated) See attached picture from a digicam.
One series was developed in Rodinal 1+50 at 24°C (75°F) for 18 minutes (i.e. 20 minutes recommended by Agfa -10% because I use a condensor head enlarger-- I usually need to reduce the recomm. dev time by about 20% but since it was overcast and not a very contrasty scene I cut it back by only 10%).
The second series was souped in Rodinal 1+50 at 18°C (65°F) for 10'45" (i.e. 12' recomm. dev time by Agfa -10%).
The third series: Rodinal 1+25 at 18°C (65°F) for 9' (i.e. 10' recomm. -10%).
Agitation: every minute 10 seconds (=5 gentle tilts). Temp constantly monitored (I kept the temp within 0.3°C deviation of the target temp at all times)
Since Agfa recommends these times for the same gamma (contrast index) of 0.55, I thought all series would come out each as contrasty as the others. Not so. The first roll had the most contrast, the second a little less and the last was the least contrasty of all. So, I need to do a second test changing the dev times to arrive at test series with the same contrast index.
These negs were printed on Ilford MGIV RC (glossy) using maximum black test (filter grade 2) to determine print exposure time (determined for each series seperately). Developed in Amaloco AM 1001 print developer for 3'.
-1+50 24°C (75°F): EI 75; dev time needs to be reduced by about 20% (guess) since zone VII does not print with sufficient detail (more like zone VIII).
-1+50 18°C (65°F): EI 75; dev time needs slight reduction (say 10%) since zone VII could do with a bit more detail
-1+25 18°C: EI 50; dev time is OK, zone VII prints with sufficient detail
The 1+50 18° gives slightly less grainy results than the 1+50 24°C, however, this could be due because the 18° series received less development (judging by the less contrasty negs). I should do another test series trying to arrive at the same contrast index to see if this result remains.
The 1+25 gives considerably more grain than both other test series even though this one was the least developed series (judging by the fact that this series produced the least contrasty negs of them all). So this test indicates that a higher dilution does indeed decrease graininess with Rodinal.
If you guys spot anything wrong with the test procedure (it's not scientific, I know), please post your recommendations! I'll try to improve the test if possible. (I don't have a densitometer in case you're wondering)
When I get the second test series done I'll post an update, but I don't think it'll be for one of these days since Belgian weather has suddenly improved a lot (they're expecting up to 30°C for the following days -- so if you don't mind I'm staying out of the darkroom! :) )
Wow. That was fast.
Surprising that Agfa's recommendations are wrong. I wonder when they last updated them. Also surprising that low dilutions would have such a marked effect on grain. Excellent work.
I shot a roll (EFKE KB100 as 100) in the backyard and as I said developed in ORdinal 1+50
- Half at 75F for 10 min (tap water temp this time of the year)
- Half at 60F for 18 min . Had to add ice to water and keep stop/fixer in ice water. To wash I progressively increased the temperature, so the first wash was at 60F, the second at 62F, the third at 65F and the fourth at 70F. I hope there is not retiuclation.
Tonality seems to be similar, but need to scan/enlarge to be sure
I'll scan tomorrow (scanner is not at home) at 2400dpi and check, but in the enlarger+grain magnifier I could barely see any difference between both parts of the roll.
Examples are in my gallery, Rodinal and temperature folder.....
I used a very similar shot I had in both parts of the roll, which I thought may show grain more prominently.
draw your own conclusions
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