Color Developing Tempered Bath Heater

[Peter De Smidt]

For cooking, I'd worry about chemicals from the plastic leaching into the food. That's why you don't want to drink plastic bottled water that's been left in your car in the summer. But that's just a hypothesis.

For darkroom use, I'd use a PID controller, thermocouple, silicone heating element (or quality aquarium heater), and a small aquarium pump. This would likely be cheaper and more versatile, as you could set it to any temp above ambient. Obviously it would be more work.

People use PID controllers for regulating the temp of smokers, fermenters, espresso machines....

[Drew Wiley]

Depends on your process. Cibachrome chem was tolerant of about 3 degree swings, while RA4 is distinctly tighter or will show color irregularity print to print.
Very tight tolerances apply to my needs only in matched color separation negatives and companion masks. For everything else, a simple water jacket works.
With tempering baths, you need to wait for the gradient to equalize, both vertically in the water itself, and in relation to the actual temp inside your chemical bottles. Recirculating pumps themselves add extra heat, which must be factored and offset with a drip line or blue ice pack if they are used for quicker equalization. Most color processes call for higher temperatures anyway, but many sheet films will risk edge frilling around 75F or above.

[highkrausen]

Jackpot! Finally got around to mixing chemistry and developing a couple test rolls of film. Here's some notes from my first (ever) color development:

First, anyone reading this that is scared of color development... Other than the temperature of the Developer/Blix, it was VERY similar, and shorter, than my B&W development.

The kit I used was Unicolor 1L. Easier than B&W to mix, but definitely much harsher chems.

The picture of the London Eye was from a roll of 35mm Kodak Gold 200. It was shot on a Minolta X-700 with banged up 50mm lens I inherited from my grandparents
Not nearly an expert in that film's capacity, but all of the frames turned out similar and within expectation given the film's "quality".

Temp Control
-heating period from 80F to 102F took about 20 minutes (obviously, could have been shortened if I used hotter water to start).
-chemistry was mixed slightly warmer than room temperature and then took about 15 min to heat up (in the future I'll do this simultaneously with the bath heating)
-the Anova cooker EASILY held the temp at 102F within less than +/- 0.3F variance (verified by 2 trustworthy thermometers - one analog and one digital).

I did not put any insulation around the tub/bin so I kept the cooker running during the development. Without it running, there was an average heat loss of about 5F in the first hour (67F ambient).

Overall...I am more than thrilled with the results and ease of using the cooker to hold tempering bath temp. I'm going to develop some Ektar 100 and Portra 400 4x5 this week. Will share those results as well. Hoping my chems will hold up a week in the fridge.

[rbultman]

Congrats. I bought the ANOVA some time ago exclusively for this purpose. It worked very well for me and it was my first time using C-41 color chemistry. I don't have a means for determining if the process was controlled well, I can only say it worked as well as the rolls I had lab-developed previously. I plan to repeat with E6 when I get a chance.

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[Ironage]

Thanks for posting this. I'll be getting one of these.


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[sheel]

Quick update... I dev'd color (C41) for the first time ever in my life yesterday, and used my Anova to maintain water.

I stored my chems in relatively thick glass, and it took me a bit of effort to get the chemicals to the right temp, but the anova maintained water temperature consistent w/ my thermometer

Samples below - please keep in mind this is my first dev, and I'm still calibrating my monitor and epson v800:

r013-06 by Sheel Kapur, on Flickr

r013-10 by Sheel Kapur, on Flickr

r013-03 by Sheel Kapur, on Flickr

[Drew Wiley]

These kinds of devices are intended for sustaining temperature, not for use as water heaters! You should start with tap water mixed just slightly below your intended working temperature. Otherwise, you're going to prematurely burn out your temp regulating device.

[highkrausen]

sheel - Great pics! What film/format?

Drew - Agree, or even start with bath water higher than your desired processing temp - assuming the chemistry will bring the bath temp down as the chems warmup.

[sheel]

sheel - Great pics! What film/format?

Drew - Agree, or even start with bath water higher than your desired processing temp - assuming the chemistry will bring the bath temp down as the chems warmup.

Thanks! It's Kodak Portra 160 6x7 using Plaubel Makina 67...

[stawastawa]

Can anyone comment on how well it works in ambient temperatures of 37*F? or subfreezing?
~nicholas