Temperature Maintenence

[beemermark]

I use SS tanks for 35 & 120. The concern isn't so much room temperature but body temperature. My hands are around 98F, quite a bit warmer than 68F. If the development time is ~10 minutes you can heat the solution up nicely depending on how you hold the tank and how often do inversions.

 

[Doremus Scudder]

When tray developing film, I place the development tray in a larger water-bath tray and use my compensating timer.

FWIW, I measured temperature drift on my set-up with an ambient temperature of 30°C (86°F) and starting with 20°C solutions. Over 15 minutes the drift was less than 1°C, largely due, I believe, to the heat of my hands in the solution.

For subsequent steps after development, the actual temperature is not so critical. It is only important that the film is transferred into a solution that has the same temperature as the one before. If one mixes everything at once to the same temperature, then the drift should be similar for all solutions and the slow increase or decrease in temperature over the entire processing time should not shock the film. Making sure the wash water is the same temperature as the last solution is important, as is making sure the wetting agent is the same as the wash.

Doremus

 

[esearing]

for 4x5 I use Pyrocat M , a SP445 plastic tank, indoors, and if doing EMA I get some drift start to finish but the long stand times may compensate. For shorter process times like 12 mins I may lose 1degree. I always start at 70*F and if its cold outside - I pre-warm the sink by running hot water in it or run the dishwasher which seems to heat the whole counter top and sink area. For Summer I use ice.

It may also depend on your choice of developer/dilution + agitation too and how it builds contrast. Pyrocat M is relatively slow when diluted below 1:1:100. Whatever you do try to be consistent and keep good notes so you can make adjustments. At the same time don't be afraid to experiment.

 

[Randy Stewart]

B&W processing commonly is done at or about room temperature, so temperature regulation is rarely a problem. Color, C-41 or E-6, does require temperature regulation, most commonly with some form of water bath. For color (only), I use a Unicolor system from the 1980s which agitates with a roller base, rolling a film drum which is heavily insulated. The loaded drum and film are brought to process temp with heated water. Once at temp, the heated processing solutions and water baths tend to maintain system temperature as each step progresses. For longer development steps, as in E-6, a "drift by" temperature control works well. (Test the temperature drop over process time for a given step, divide by 2 and add that amount to the starting temp for the step. So, a developer may start 2 degrees over the recommended temp and end 2 degrees below. Sounds funky but it works well. Since other process steps go to completion in E-6, I can make that temp adjustment for the developers and apply it to all of the process steps, so separate temperatures for each chemical is not required.)

 

[focus_on_infinity]

B&W processing commonly is done at or about room temperature, so temperature regulation is rarely a problem. Color, C-41 or E-6, does require temperature regulation, most commonly with some form of water bath. For color (only), I use a Unicolor system from the 1980s which agitates with a roller base, rolling a film drum which is heavily insulated. The loaded drum and film are brought to process temp with heated water. Once at temp, the heated processing solutions and water baths tend to maintain system temperature as each step progresses. For longer development steps, as in E-6, a "drift by" temperature control works well. (Test the temperature drop over process time for a given step, divide by 2 and add that amount to the starting temp for the step. So, a developer may start 2 degrees over the recommended temp and end 2 degrees below. Sounds funky but it works well. Since other process steps go to completion in E-6, I can make that temp adjustment for the developers and apply it to all of the process steps, so separate temperatures for each chemical is not required.)

My own experiments at room temperature indicated it wasn't worth it to use a water bath for b&w. At most, one might go up by a degree for a longer developing time.

I wondered how risky it is to do a drift bu for color in general. I've read about color issues when there are sudden temperature changes, but I don't really know what constitutes 'sudden'. That said, with a sous vide it's pretty easy to do a water bath.

 

[RalphLambrecht]

I notice that in almost all videos on developing I've seen, and all tutorials, there doesn't seem to be any temperature maintenence once the developer is in the tank. i.e. other than agitation, the tank just sits there. I haven't yet seen someone set the tank into a water bath to hold temperature.

And while one may adjust one's processes accordingly for B&W, it seems like it just might be good practice if one also does or intends to do C41 or E6.

What say you? A good idea or not?

god idea and executed everywhere; look at the Jobo processors;they rotate the tank in a tempered bath!

 

[Adrian Bacon]

I notice that in almost all videos on developing I've seen, and all tutorials, there doesn't seem to be any temperature maintenence once the developer is in the tank. i.e. other than agitation, the tank just sits there. I haven't yet seen someone set the tank into a water bath to hold temperature.

And while one may adjust one's processess accordingly for B&W, it seems like it just might be good practice if one also does or intends to do C41 or E6.

What say you? A good idea or not?

I use a JOBO with a tempering bath, even for black and white.

 

[Doc W]

Most people don't talk about maintaining water temperature constant because they live in houses with proper insulation and usually have some kind of climate control which keeps the house constant all year round.

I live in an old house in Canada and the temperature in my basement darkroom can vary widely. Even crazily. Also, the ground water is extremely cold in winter and gets very warm on the really hot days in summer. With all of the experimentation I did to try to keep the developer bath at a constant temperature, I probably could have got the darkroom insulated properly. Maybe someday. I finally caved in a got a Jobo. Smartest thing I ever did. I don't worry about temperature at all. In the winter, the Jobo heats it up just fine. When it is stinking hot in the summer, I put freezer packs in the bath (keeping it away from gears, etc.) and the Jobo does the trick.