Heat

[DBP]

I was looking through an old photographic text the other night looking for information on old developers (in response to a thread here) and happened across a section on using heat in development. I seem to recall that press photographers used to use warm dektol to get fast results and high film speeds. Given that the tap water here is approaching 80 degrees F (27 C) and the room temp in my darkroom is the same, is there any technique involving warm developer that is worth trying with modern film?

 

[pentaxuser]

There is usually a range of temps at which B&W developers can be used at. Ilford for example list a conversion chart which gives the altered time from the standard 20 degrees C or 68 degrees F.

The only issue with temps way above 68 is that this can reduce with certain films and dev combos, the dev time to a very reduced time which can bring its own problems. For example 10 secs too much at say 12 mins isn't going to have anything like the effect that 10 secs will have at say 3 mins.

On the other hand colour neg films have a standard of 3 mins 15 secs which is short and yet most who do their own developing seem to manage.

No doubt others can shed more light on what an upper limit temp wise might be.

I think I'd feel more relaxed developing at a temp which didn't exceed the 70s but in your case this might involve a water bath which had been cooled to keep the temp down.

pentaxuser

 

[DBP]

I can get the water temp down easily enough, given that I have a fridge in the darkroom and mostly use Rodinal and HC-110 where I can use cooled water, and Diafine, where temp doesn't really matter. But are there any techniques that would take advantage of the higher temps for a good effect?

 

[Thomas Bertilsson]

I may be talking out of my hat here, but I don't think the temperature has any real effect other than having to shorten the time.
I know that the pyro developer I use is fine to use in temperatures higher than the 68*F / 20*C that seems to be the standard.

- Thom

 

[Bob Carnie]

DBP
I may be mistaken but are you referring to hot water tray beside the dectol tray.
This was prevelant in press photos , the printer would basically dip their hands in the hot water and apply their hands to areas of the print that they thought were not comming up fast enough.
fast and furious was the mode.
I have tried this hot water application , and I prefer to not use it as it is usually obvious in the print when it was applied.
It works and could be a tool to use but in a pinch .

 

[pentaxuser]

I suspect that if high water temp and therefore high dev temps imparted anything special to film dev which wasn't there at "normal" temps then B&W books would devote a section to it. If there are any techniques only available with high temps then I haven't seen them mentioned in any B&W books I've read.

pentaxuser

 

[Monophoto]

There is a strong tradition of targeting 68deg F /20deg C for photo processing. The rationale for this is that this is the only temperature that appears as the same mark on dual-scale thermometers. Other temperatures would work just as well, but if the instructions called for, say 65 deg F, it would also have to say 18.333 deg C, and that's too complicated for some folks.

When you deviate from the "standard" temperature, processing times will change - shorter with higher temperatures, and longer with lower temperatures. When processing film, the main advantage of changing temperatures is to accelerate processing. Frankly, I don't think that's worth the hassle of trying to remember what to do at temperatures other than standard. Fixing time doesn't appreciably change with temperature, nor does wash, so the overall wet time isn't going to change enough to make it worthwhile.

When printing, however, there are tricks that you can use that involve temperature. If you have a print where there is an area that is "weak", having a small container of heated developer that you can brush onto the spot may help bring out detail that would be hard to achieve using other techniques. Variations on this theme include rubbing the area so that the heat from your finger causes the local temperature to rise, or simply blowing on the area so that your breath accomplishes the locallized warming.

In Pt/Pd printing, having a heated developer will result in a slight increase in image warmth. Also, while development is theoretically instantaneous, it may actually take a few second for cooler developer to soak into the print whereas warmer developer will be faster.

 

[Jim Jones]

I routinely process film and paper at whatever temperature prevails in the darkroom. This has caused no problems up to 85 degrees F. With the necessarily short film developing time at elevated temperatures, a pre-wash is advisable.