Constant 68 Degrees...How?

[keith english]

I keep a gallon jug of water in the refrigerator to mix with room temperature water for the developer (in the summer). Tap water is cool enough in the winter. Here in Georgia I haven't figured out how to cool the wash water, since it comes out of the tap at 85 degress or higher, in the summer.

[jp]

I used to mix water with developer too. Just average the two temperatures if you are doing 1:1 dilution like with d76 or xtol.

[Bob McCarthy]

I keep a gallon jug of water in the refrigerator to mix with room temperature water for the developer (in the summer). Tap water is cool enough in the winter. Here in Georgia I haven't figured out how to cool the wash water, since it comes out of the tap at 85 degress or higher, in the summer.

FWIW, I have a similar issue in texas during the summer. I keep 5 gallons of filtered water on hand which is roughly room temperature as its equilibrated first (overnight storage at room temp). I wash using 5 changes (as recommended by the film companies) with plenty of soak/agitation between changes - rather than with running water.

A little more time consuming than running water and ignoring, but appears to work well and doesn't melt the emulsion.

bob

[Brian Ellis]

There's nothing magic about 68 degrees - any temperature within reason is fine as long as you're consistent in using that temperature. And you only have to worry about consistency with your developers. The temperatures of stop and fix can bounce around all over the place during the course of a darkroom session and as long as you aren't letting them get ridiculously hot or cold it won't matter, they'll work fine.

I processed film in developer at 75 degrees since developing at a warmer temperature than 68 speeds the process up a little. I kept it at 75 by rolling the tubes (I used the BTZS tubes) in a water jacket that was a few degrees cooler than 75 (keeping the water at 75 didn't keep the developer at 75, probably because of the hand-agitation that's done with the BTZS tubes). For paper developer I used a Zone VI Studios Compensating Developer timer which IIRC is calibrated at 68 degrees. I set the time at 2 minutes. The timer automatically adjusted the actual time up or down as the temperature of the developer went up or down from the calibrated 68 degree starting point. I doubt that these timers are made any more but if you can fine one on the used market for a reasonable price they're well worth having.

[Ben Calwell]

Ansel Adams will probably roll over in his grave, but I recently developed some sheet film that ended up in a tray of fixer that was at least 10 degrees or more colder than the developer and stop.
You could hang meat in my darkroom, as it is in my unheated basement. I had forgotten to get the fixer warmed up, a mistake that became immediately apparent to me when my hands plunged into the fixer tray's icy depths.
Despite this, the film looks just fine.

[jp]

If your fixer is <60f, it takes a lot longer to fix film. Fix by inspection sometime with tmax film; you can see it clear during the first half of the fixing.

I imagine paper would also be less responsive to cold fixer.

[neil poulsen]

Adams commented in his book that Dektol changes developing characteristics (not just slower), when the temperature gets down to about 65 degrees. It contains a couple of active ingredients (hydroquinine and metol?), and one of them shuts down at lower temperatures. So, that effectively changes the ratio of one active ingredient to the other at cooler temperatures.

For me, the ideal would be a well insulated darkroom that always stays at the same temperature. So, never any heating up or cooling down of chemistry to get to the right temperature. Just take it off the shelf, remove the cap, and it's ready to go. One could have distilled water in a tank with a spigot that sits on a shelf. Again, it's always at the correct temperature.

And I'll comment, the ideal temperature for me IS NOT 68 deg. F! That is frigging cold.

[Ed Pierce]

Here in Vermont my darkroom is often colder than 68F. When setting up to process film, the first thing I do is fill a tray with hot water and put my bottles of chemistry in the tray until they're warmed up.

To keep my developer temp constant during printing, I use two trays. In the larger bottom tray I put four short pieces of pvc pipe to set the top developer tray on, fill the tray with water a few degrees warmer than the desired temp, and put in a submersible aquarium heater. The water level should just reach the bottom of the developer tray. It took a few sessions to hit on the right setting on the heater, but now the dev temp will stay the same all day long.

[Kirk Keyes]

I develop B&W in my Jobo at 75F as that seems to be the water temperature here in Ohio in the summer.

THat's exactly what I do too - even though I am in Oregon.