I am moving to B&W from color, and don't use my Jobo to print. How do I keep developer at 68 degrees? My darkroom is hotter than that. Does anybody know any thermo device I could use to cool down and keep the developer's temperature constant?

-- Boris Krivoruk (boris_krivoruk@ams.com), May 10, 2000

Answers

Boris, are you asking about film or paper developer?

You can keep your film developer at a pretty constant temperature by placing it in a tray filled with water at the temp you desire.

I do NOT keep my paper developer at anything other than room temperature, and I live on an island in the Gulf of Mexico. I also do not immerse my film tank in a water tray, but only get the developer to the desire temp before I pour it into the tank.

B&W is not nearly as sensitive to temperature variations as color.

However, it does depend on how precise you want to be to achieve the results, which will satisfy you.

chris

-- Christian Harkness (chris.harkness@eudoramail.com), May 10, 2000.

Temperature is still an important factor in getting repeatable results with your black and white. I use a Zone VI Compensating Development Timer that varies the rate that seconds tick off according to the temperature of your developer. It helps to get repeatable results from one day to the next or one hour to the next if your darkroom changes.

-- Jeff White (zonie@computer-concepts.com), May 10, 2000.

Some people put developer trays in larger trays with water and ice, but this requires attention to avoid too much cooling. For conventional b&w printing, I wouldn't bother. A few months each year, my darkroom (actually our family bathroom) is somewhat warmer than 200C (up to 260C), and a few months, it is a bit colder (down to 180C), and I never found this to be a problem in printing. Considering that b&w prints are developed to finality, this is plausible.

For film development, otoh, the requirement that temperature is constant (not necessarily 200C) is more critical, if you want consistency. It must also not climb so high that developing times become too short (less than 5 minutes, I would say), or that the emulsion becomes too soft and vulnerable. Room temperature that is slightly too high is probably better than forced cooling, because it is fairly constant, whereas forced cooling might result in irreproducible ups and downs during the development time.

If you think you must cool, I would recommend an experiment: Temper the required volume of tap water to the desired temperature and watch the change in temperature over the time you intend to develop, applying representative agitation (stir the soup with the thermometer). If the rise in temperature is less than 10C, either forget it, or start with an initial temperature half a degree below the desired value. It should then be half a degree above afterwards, and I think this cancels out neatly.

If it's two degrees or more, you might want to use a larger volume, because this has more "inertia". You might also try to use the same volume as before, but put the tray in a larger tray with a large volume of water at the desired initial temperature (or slightly below), thus indirectly using the inertia of the large volume.

In many not-so-extreme situations, these methods might help. At worst, buy a portable air-conditioning unit.

-- Thomas Wollstein (thomas_wollstein@web.de), May 11, 2000.

You don't say what sort of temperature your darkroom gets to. Anything up to 80 degrees Farenheit is nothing to get worried about, you'll just be developing your prints for 2 minutes or so instead of 3, and your solutions will evaporate out of the dishes a bit quicker. Anything above that, and I'd add some restrainer to the developer or try to get the temperature down a bit. The simplest way might be to stand the trays on a towel or thin sponge mat soaked in cold water. The evaporation should lower the temperature by a few degrees. (I haven't actually tried this. My main problem's keeping the temperature high enough in the winter months, when I try to catch up on my printing)

-- Pete Andrews (p.l.andrews@bham.ac.uk), May 11, 2000.

You can also put some ice cubes in a ziploc bag, throw it into your developer tray, and swish it around for a while... with a thermometer in there too, so you know when to take it out.

(My parents the pros also use this technique to cool down deep tanks of endlessly-replenished standing DK-50 they use for 4x5 b/w film. They used to waterjacket these too [they used to have a 2-feet deep sink surrounding the sheet-film tanks], but the old Kodak hard-rubber deep tanks are pretty resistant to external cooling.)

This works fine for quick cool-downs. If you are printing under very hot conditions (ambient temps above 85F), the suggestion made above of putting the tray within a larger tray (e.g., 9x12 within 11x14) and waterjacketing with cool water - and a few loose ice cubes, if needed - is better for continual adjustments.

And, for the record, I agree with what a couple of folks have already said - temperature is not really critical for print developer. Anything in the 65F to 80F range will work fine (though prints will develop more quickly at the higher temps). Of course, film development is a DRAMATICALLY different story...

-- Michael Goldfarb (mgoldfar@mobius-inc.com), May 11, 2000.

Thank you all for your ideas. I will need to implement them for B&W printing. I live in Colorado, and my darkroom is a converted bedroom, which is on the sunny side, it gets really hot, above 80 degrees. I liked the idea of putting ziplock with the icecubes into the developer. I am not really sure about compensating timer: how does it know all inticacies of all paper/developer combinations; it probably does not. Or is it programmable? I guess, I have to experiment using your ideas, starting with low-cost solutions first.

-- Boris Krivoruk (boris_krivoruk@ams.com), May 12, 2000.

To answer your question on the compensating timer. Using the standard paper developers and the currently available papers the resposne to temperature variation is the same. There have been at least a couple of articles that have came to this conclusion. I bought my timer over ten years ago and it has easily paid for itself in less paper waste and wasted time.

-- Jeff White (zonie@computer-concepts.com), May 12, 2000.