Canon-AE1
Hello everyone.
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How exactly do you measure the temperature of the developer? Today, after ten minutes of developing, I stuck the thermometer into the tube of the can and found that the temperature had risen from 18 degrees when I poured it in to 21 degrees! In the summer, I always place my can on a large ice pack during the agitation intervals, but that doesn’t seem to make any difference.
How do you handle this?
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Best regards
Bonderer
I have the TAS processor, so I don’t actually hold the tins in my hands. When I asked AGFA, they told me that the first few minutes are crucial and that the developer certainly won’t heat up that quickly. The important thing is the temperature when you pour it in. How on earth are you supposed to maintain a constant temperature with a tilt-and-turn developer?
If it were that dramatic, you’d have to handle your films only under climate-controlled conditions and with thermal gloves, which would be more than impractical.
Developer with Rodinal, but thanks to TAS, without any manual contact. My darkroom is nice and warm in summer and quite cool in winter, as it isn’t heated very much. I haven’t noticed any differences, nor can I afford to for my friend, given that he’s a photojournalist.
I would say that photographic processes are so stable nowadays that such variations, whether up or down, have no effect or only a minimal one once development has begun.
highscore
Well, I’d have to agree with Analoger’s experience
In my house, temperatures can easily reach 30°C in the summer!
But never mind that.
Once my film has reached 20°C, I develop it.
That said, I haven’t noticed any difference between summer and winter.
I’m sure they’d be detectable with the right equipment.
But never mind that, on to the second point.
The compensation just happens subconsciously during enlargement.
And I don’t do long-exposure development with, say, homeopathic Rodinal anyway.
(But colour development at room temperature?? Hmmm, I should give that a go)
Regards
highscore
ThomasPauly
I usually work at 24 degrees. This temperature is easy to maintain even during the warmer months. It’s easier to heat the room in winter than to cool it down in summer. I haven’t noticed any difference in quality compared to 20 degrees with the developers I use (D-76, Perceptol, Silvermax). The reduction in development time, usually by 25–30%, is a welcome side effect.
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Best regards
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tepe
grommi
I find that a water bath with cool water in a small bowl is quite useful in the summer. That way, you don’t need any fancy equipment. Otherwise, I compensate for the development time by 10% for every degree of deviation, which is accurate enough for my purposes.
jonny
I assume this is about Rodinal (why else would anyone want to develop at 18°C?) in conjunction with development times exceeding 10 minutes. The problem could be avoided by adjusting the development time to room temperature (e.g. 20°C in spring/autumn/winter, summer 24 degrees if necessary) and adjusting the times accordingly, or simply ‘letting the temperature drift’ (T-in 18° -> T-out 22° = times as for 20?), but Rodinal apparently has to be developed cold to bring out its best qualities. So if it absolutely has to be a constant 18 degrees, you should bear the following in mind:
The ice pack is of no use to you, because heat transfer from the pack to the can is poor. The contact surface is small and air is a poor heat conductor. Furthermore, this cools the can unevenly (from below). You need the largest possible container (a sink, or better still a small plastic tub) filled with water at around 18 degrees (where I live, the tap water is still coming out at 17 degrees and I don’t live in Hamburg) or chilled water (ice cubes), into which you place the can unless you’re about to pass out. That should be enough to keep the temperature stable. A test run without film (using reels and water instead of developer) may provide some insight.
