My "No waterbath" C-41 Processing

Paul Verizzo · Jan 12, 2011

I quickly got tired of getting multiple gallons of water up to temperature, holding it there, and fishing out my steel tank every thirty seconds during development.

So I switched to my plastic Yankee Master tank and did some experiments with plain water and a digital thermometer. Despite the disdain many here hold for plastic tanks, I love mine. Fast pour in and out, no slipping of the lid off (I had that happen once, granted, my bad) and now, I can insert my thermometer into the developer. And if that wasn't enough, the better insulative qualities of the plastic.

In a 3:30 development time, the liquid loses only about 1.7 degrees F.

With lots of experiments and the handy microwave to warm the 625 ml of water that the tank holds, I set to work. Since the tank and contents needs to come up to 102 degrees from room temperature, I added extra heat to the water, then measured temperatures as it went through 3:30 of change (times and temps are for my Unicolor chemicals.)

The end result: Start at 107 degrees, pour. The temperature will drop 4 degrees as the tank and film comes up to temp, now we are at 103 degrees. I agitated by rapid swirling since I wanted to leave the thermometer in to equalize the water temp internally. At the end of 3:30, it's at 101 degrees, averaging, ta ta, 102 degrees.

Both of my digital thermometers, ironically, have bad readouts on the 1/10 degree digit, so I'm going to get a new one ASAP. That will let me fine tune this a bit. This is the one I like the best: http://www.harborfreight.com/instant-read-digital-thermometer-95382.html , better than my more expensive lab grade one. El cheapo agrees with the lab one within a couple of tenths, it's easier to read, and faster to respond.

It should go w/o saying, YMMV!

hpulley · Jan 12, 2011

Yery interesting! I'm using Paterson Super System 4 plastic for color mostly because my old Nikors leak under pressure and the blix really needs some burping I find. But I am using a water bath, both to get my dev and blix up to temp and to hold the plastic tank as I work starting at 39C or 40C when I can.

Not having to use the water bath would be nice so it is good to hear of your experiment.

Have you considered a pre-soak so that the developer loses less temperature when you pour it in? I normally do a pre-soak for one minute with hot water so that the dev doesn't drop when it goes in.

brucemuir · Jan 12, 2011

I ran a similar test once and my findings are similar although I would imagine ambient temp could play a part. It gets quite cold at this time of year in my utility/film processing area that has the slop sink so I may run another test.

I usually run a dishpan thing for my water bath with no heater and fudge things as I go.
This of course is not optimal but I've been getting great results with manageable color shift if any.

Paul, thanks for that Harbor Freight link. I got a cheapo digi readout thermo from ebay and it quit after about 8-9 months. I did test it against my mercury thermos and all was good but those cheaper models have a plus/minus 1.8 degree F margin for error. Hopefully this would be okay considering.

Paul Verizzo · Jan 12, 2011

hpulley said:
Yery interesting! I'm using Paterson Super System 4 plastic for color mostly because my old Nikors leak under pressure and the blix really needs some burping I find. I thought it was my imagination or mishandling! Good to hear, and I'll take measures from now on. But I am using a water bath, both to get my dev and blix up to temp and to hold the plastic tank as I work starting at 39C or 40C when I can. No need to with my system. Warm blix in the microwave if you wish.

Not having to use the water bath would be nice so it is good to hear of your experiment.

Have you considered a pre-soak so that the developer loses less temperature when you pour it in? My system avoids that. Keep life simple. I think the use of a presoak on all of the consumer kits is to avoid developer temperature drop more than anything. Just my opinion. I normally do a pre-soak for one minute with hot water so that the dev doesn't drop when it goes in.

I'm sure your tank would work as well, just always use maximum liquid for better thermal control. I want to make color as simple as B&W, I think this does it.

Also, if one's intended use is to scan the film and go from there, super accurate temperature and other controls is not needed. "Good enough."

Paul Verizzo · Jan 12, 2011

brucemuir said:
I ran a similar test once and my findings are similar although I would imagine ambient temp could play a part. Yes, I'm sure, but not as much as one might think. There just isn't much latent heat in plastic or film. If you have concerns about your work area, let the tank warm to 70-75 degrees in your living area and then just go to the work area with the developer ready. It gets quite cold at this time of year in my utility/fim processing area that has the slop sink so I may run another test.

Paul, thanks for that Harbor Freight link. I got a cheapo digi readout thermo from ebay and it quit after about 8-9 months. I did test it against my mercury thermos and all was good but those cheaper models have a plus/minus 1.8 degree F margin for error. Hopefully this would be okay considering. Consumer grade digital thermometers have quite a +/- margin, as do analog thermometers. I think in the real world they do much better. Go to Wart-Mart and look at the thermometers. Typically you will see they almost all read the same. Almost! The important thing is consistency, not exactitude.

Digital reliability is an oxymoron. I have display problems with both of my thermometers, as said, and my microwave. I've had four out of five digital cameras need factory repair. (Present Minolta A2 doing well, fingers crossed.) Some of the issues, I think, are because cost is always a concern, so things get done on the cheap. I also think some is due to this is all brand new in relative terms, and just like it took 80 years for cars to become reliable, maybe digital is going through its adolescence.

domaz · Jan 12, 2011

Hmm interesting. Makes me wonder if you could just put the whole tank in the Microwave during processing and run it every few seconds to keep temperature up. Now that would be a unique way to hold temperature.

Paul Verizzo · Jan 12, 2011

domaz said:
Hmm interesting. Makes me wonder if you could just put the whole tank in the Microwave during processing and run it every few seconds to keep temperature up. Now that would be a unique way to hold temperature.

I warmed a tank once in the microwave as an experiment. My concern was the four little steel balls in the reels. But there was no problem.

The problem is lack of control and trying to agitate every 30 seconds and check the temp, which takes almost 30 seconds for the thermometer to stabilize.

Just start off a bit hot, and you are done with it all. K.I.S.

2F/2F · Jan 12, 2011

Doing C-41 without a water bath is a good reason to use plastic tanks. You only need to hold the 100 F average temperature for 3:15. I probably would not try it with a metal tank unless ambient temp was close to 100 F.

I am kind of confused by your numbers. When is the 4 F drop occurring? If the developer drops 1.7 F from beginning to end of the first step, and you are processing at 102 F (odd to me, but I guess some kits use 102 F instead of 100 F), you should half 1.7 F and add the result to 102 to find your starting temp (102.85 F).

hpulley · Jan 12, 2011

He is losing 4 degrees when he pours into the tank since he isn't doing a 102F pre-soak to warm up the tank.

Paul Verizzo · Jan 12, 2011

2F/2F said:
I am kind of confused by your numbers. When is the 4 F drop occurring? If the developer drops 1.7 F from beginning to end of the first step, and you are processing at 102 F (odd to me, but I guess some kits use 102 F instead of 100 F), you should half 1.7 F and add the result to 102 to find your starting temp (102.85 F).

The 4 degree drop comes from the 107 degree developer being rapidly cooled by the 70 degree tank and reels.

As to the numbers, I'm just rounding off. As explained, my thermometer has a fluky one tenth degree digit, so I was interpreting as best as I could.

But fear not! I bought a new thermometer for $5.30 with tax at Harbor Freight and will run more experiments tonight or tomorrow.

2F/2F · Jan 12, 2011

OK, so tell me if this is right. Your developer first hits the film at 107 F, and you pour it out at 101 F?

Or do you put the developer in an empty tank at 107 F, wait till it hits 103 F, and then put the film in in total darkness?

The problem I am seeing with the former way is that the film hits the developer at 107 F and cools down to only 101 F, making the average temp 104 F. Where are you making the separation between the 107 to 104 drop and the 103 to 101 drop?

What about using hot water at 103 F to warm up your film and tank before pouring in 103 F developer?

I am sorry if I am being dense.

fschifano · Jan 12, 2011

brucemuir said:
...I got a cheapo digi readout thermo from ebay and it quit after about 8-9 months. I did test it against my mercury thermos and all was good but those cheaper models have a plus/minus 1.8 degree F margin for error. Hopefully this would be okay considering.

Yes, do be careful with these cheap digital thermometers. I've found that they can be off by quite a bit. The ones I have are up to 1.5 deg. F off my calibration standard Paterson color thermometer. That's OK though because they're consistently off. They do go bad after a while and that's OK too 'cause they're cheap.

Paul Verizzo · Jan 12, 2011

2F/2F said:
OK, so tell me if this is right. Your developer first hits the film at 107 F, and you pour it out at 101 F? This is correct.

Or do you put the developer in an empty tank at 107 F, wait till it hits 103 F, and then put the film in in total darkness? No.

The problem I am seeing with the former way is that the film hits the developer at 107 F and cools down to only 101 F, making the average temp 104 F. Where are you making the separation between the 107 to 104 drop and the 103 to 101 drop? A good logical observation requiring amplification! Although the film is hit with 107 degree developer, the cooler tank and reels bring it down to 104 within some few seconds. From there it coasts downward to 101.

What about using hot water at 103 F to warm up your film and tank before pouring in 103 F developer? That should work, too, buy why have another step?

I am sorry if I am being dense.

Good questions, no density seen.

Paul Verizzo · Jan 13, 2011

2F/2F said:
What about using hot water at 103 F to warm up your film and tank before pouring in 103 F developer?.

Upon further reflection, your proposal would give more accurate time/temperature control. Then two further questions arise, in my view. One is, "Is it necessary?". In other words, is there visible difference? Two is, "If the answer to the first question is, 'Yes,' then can't a guy just reduce the development time by a short amount?" I presume the answer is "Yes."

I guess it gets back to the burning question of just how perfect does one have to be in the processing of color film. I mean, there's that old +/- .25 degree temperature MUST be maintained...........and yet, in the real world, we soon find out that is BS. Especially if scanning the results, not printing. I think a lot of that anal retentive thinking was tight controls for analog printing, it would make the printing easier. But within reason, for scanning, it doesn't matter. Probably not for computer analyzed printing, either.

As I first posted, these experiments were done with water, not developer. Since I don't have a densitometer, I probably couldn't tell any difference if the film got cooked a bit much on the front end, or how much to kill the process by on the back end, if needed.

I'll experiment a bit more, focusing on the initial drop. I've got that new thermometer, and I can also use my little infrared one to measure outside tank temperature. It reacts faster than the digital thermometer, although, I guess, there will be a slight difference between the liquid temperature and the outside of the tank.

Whichever way this pans out, I won't be going back to waterbaths!

glbeas · Jan 13, 2011

From what I've read that anal urge to keep the temperatures totally even has to do with color crossover between the dye layers that can compromise color accuracy in ways that cannot be compensated for by any scanning algorithm. That said most folks aren't going to quibble much over this and the human mind can compensate for such when viewing a scene and even enjoy a bit of wierd color on occasion.
I've found you can do your preheat by placing the tank in a warm water bath to heat the container and reels and not pre rinse. Another option there.
I've even seen a dip 'n dunk system built in a cabinet totally regulated by warm air under the deck the tanks were inset into.

Paul Verizzo · Jan 13, 2011

We've all heard this stuff for years, glbeas. But is it true? Or, under what conditions? Photography is loaded with urban legends, i.e., "Borax gives finer grain than other alkalies." Borax "gives" finer grain because of the low pH, longer development, more time for the sodium sulfite to take the hard edge off of the grain. (And you can't just use a teensy bit of carbonate because there are no buffering reserves.)

How does one maintain +/- a quarter of a degree even in commercial operations? Are those thermostats THAT sensitive? Are the thermometers THAT accurate? I've yet to see either type of component at the consumer or lab level.

And then there's the "You CAN'T develop at lower temperatures, it just won't work right!" And yet, like the bumble bee that "can't" fly, it works. I saw where a guy on flicker has successfully use dilute C-41 as a stand developer.

I'll bet you can't do that!

hpulley · Jan 13, 2011

The Tetenal sheets give low temperature times for machines, but not for tanks. For 75F which is room temperature in some places, the developer time is 17:30 and blix is 8:00. The time for 104F with the same machine is 3:30 which is the same time for hand agitated tank at 102F. So hand agitation seems to be a bit faster, needs lower temperature for the same time. So if you really wanted to you could probably even do longer for 68F in a hand tank, perhaps 22:00? It seems the blix time maxes out at 8:00 once the temp drops to 90F so that's half an hour dev and blix, followed by some wash. 3:30 + 6:30 is 10 minutes so you waste time there doing it at room temp but I probably spend 20 minutes getting the water bath set up properly and the dev and blix up to temperature for the first roll anyways!

The sheet recommends 104F in that machine however, not the lower temperatures so I don't know if there will be color issues. 37C/100F is the lowest I've done it by hand.

Paul Verizzo · Jan 13, 2011

I tried to find answers to these differences, you may recall on another thread: (there was a url link here which no longer exists)

This is just a guess, but I'm thinking that the Unicolor drum is unheated, I've heard, so it starts at 104 degrees. The times are different, as I'm sure you know, in the heated processors.

I think it all confirms that this process isn't near as critical as always thought.

My "No waterbath" C-41 Processing

Privacy & Transparency

Privacy & Transparency