Temperature control in C41 - manual process

ashokgoyal42 · May 14, 2011

How does one control the temperature for the crucial developer process in C41?

I've been heating the Patterson film holder so that the heat doesn't dissipate but despite that when I pour the developer at 39 degrees - it shows 37 within a few seconds.

Should I set the developer at 40C and then let it fall to 38? Any ideas?

Ottrdaemmerung · May 14, 2011

Use a water bath. Fill a container (like a styrofoam cooler, a plastic bin, or your sink) with warm water until it comes up to about 2/3 the height of your Paterson tank. During the developing process, between inversions, let the tank sit in the bath so that the chemicals inside don't have a chance to cool down.

hpulley · May 14, 2011

I use a simple Rubbermade container water bath AND a 1 minute pre-soak. I pre-heat the developer and blix to 39C and also prepare a pre-soak (same volume as developer) at 39C. This way the tank is already close to 39C before the developer goes in. Using a Paterson plastic tank with the pre-soak and keeping it in the water bath except while inverting I don't lose temperature over the 3:30. The blix is not as crucial, can be even warmer like 40.5C as it goes to completion. Rinse water again isn't as crucial, 35-40C or so. Don't let it get too hot though, you can melt the emulsion at 50C.

Diapositivo · May 14, 2011

Even better, two 30-seconds pre-soaks (at treatment temperature) rather than one. The water of the first pre-soak cedes heat to the film and tank, and cools a bit down (somehow half-way between film temperature and water temperature, I guess), the second pre-soak sets the film further near the right temperature.

hpulley · May 14, 2011

Another thing, if you're doing more than one tank in a row, keep the developer and blix bottles in a bucket of 45C water or so to keep it at 40C until you use the next tank. If I could figure out how to load 2 120 films on a single 120/220 reel I wouldn't have to do this but as it is I often have 3-4 120 rolls to do and with only 1L of solution I need to do 2 batches. I need to practice with film and tape in the light to see how to do it, I can't seem to get the second roll to stop sticking when it's been taped...

I suppose if I got a 2L solution or bought some one shot Kodak Flexicolor kit bottles then I could get a bigger Paterson Super System 4 tank and do 4-5 120 rolls at once in their biggest model.

ashokgoyal42 · May 15, 2011

Thanks everyone. Pre soak is a good idea - that should help reduce the temp drop significantly. Also good is keeping the Patterson inside the water bath in between inversions.

Athiril · May 15, 2011

45c presoak in a plastic processing tank, pour in developer when its up to temperature after draining tank.

Mike Wilde · May 16, 2011

hpulley said:
If I could figure out how to load 2 120 films on a single 120/220 reel I wouldn't have to do this.

I load on Paterson reels. I find the white newest version of plastic works best, as it seems to be the slippiest, but all will work.

Load the first film. Once it is past the ball bearings, place a thumb on the end of the film, and while continuing to walk the reel back and forth, you can feel the film continuing down the spiral. A very gentle pressure may be needed to push the thing along.

At some point it will not spiral in any more, and you will fiddle for a second or two before you are sure this is the case. This is normal for me, even after doing this for quite a while.

I then begin to load the second 120 film. I usually take the backing paper off first, but be sure to do so for this second roll. I hook a pinky finger of my 'still' hand into the film to keep it from getting too close to the guide path and getting stuck. When I feel the roll to be loaded disappearing, I slow down on the reel rocking, and stop just after I feel the film get onto the spirals.

I would recommend pratciting with scrap rolls first, but it does reliably work for me.

hpulley · May 16, 2011

Interesting. Too bad I don't have any wasted film to practice on. Next one I respool onto 620 and shoot through the Tourist I could try as the first roll I suppose, it will already have had a fairly rough life...

jm94 · May 23, 2011

When i did C-41 i found it easier at ambient temperature, increasing the times. I used the nova press kit, which also includes a table. I find the chemicals alot more tolorent at 20 - 24C than higher. 24C i usually develop for 7:30 minutes. Blix isnt as critical as the developer, i prefer to use a stop bath also. Tetenal chemicals (2 bath) seem to hold up well at 24C for me aswell. I use tank processing. The rollei (agfa) and Fuji i cannot comment on. You might find it easier to go down the room temperature (20C) route, if you do not mind increasing the times. Experiment

mikecnichols · May 23, 2011

I've got a heating element in a ~13x9x4 plastic container. It seems to heat itself to about 50ºC. The "tank" was my wife's grandfather's (along with most of my other darkroom equipment). I'm going to build a new one using a water heater element connected to a water heater thermostat to give a better control on my temperatures. For RA4, my current setup is perfect, but for C41, I need the water to stay hotter but not too hot.

tomalophicon · May 23, 2011

I use what is basically on of these.

At the very low setting it heats water to exactly the temperature I want.

I just put my flasks in there and wait and hour or more for them to get to the right temperature.

Then I put my reel tank in until it heats itself up. There have been no problems so far with a drop below crucial developing temperature.

ashokgoyal42 · Jun 7, 2011

I've ordered a customized temperature controller in stainless steel which has a capacity to store 8 1 liter bottles of chemicals (I intend to use this for E6 too). I got quite a bargain and I'm hoping that the product turns out as promised. It has an accuracy of 1/2 degree centigrade. Hopefully this will take my developing to a more accurate level and make it trouble free. At least for C41 and E6. I'll post some pictures when it arrives. Thanks everyone for your feedback and response.

tnabbott · Jun 8, 2011

ashokgoyal42 said:
I've ordered a customized temperature controller in stainless steel which has a capacity to store 8 1 liter bottles of chemicals (I intend to use this for E6 too). I got quite a bargain and I'm hoping that the product turns out as promised. It has an accuracy of 1/2 degree centigrade. Hopefully this will take my developing to a more accurate level and make it trouble free. At least for C41 and E6. I'll post some pictures when it arrives. Thanks everyone for your feedback and response.

Can you please provide specifics of the controller or a link to the website? TIA!

Trasselblad · Jun 8, 2011

I use Unicolor 3 bath press kit and prefer processing at 30C. It will work down to room temps as well, but I didn't try that. At 30C, the temp is much easier to control (microwave plus water bath), plus an added benefit is that the processing time errors one may inadvertently introduce become less important. 5 seconds of 3.5 minutes is a bigger problem than 5 seconds of seven minutes. Works fine with no noticable colour shifts.

Instructions call for a one minute pre-soak. Tried with and without with no noticable difference. I do also put the tank in the water bath for a few minutes together with the chems. I use steel tanks and rolls for 120 and plastic for 135. Find those combinations easiest to load.

ashokgoyal42 · Jun 10, 2011

tnabbott said:
Can you please provide specifics of the controller or a link to the website? TIA!

Hello tnabbott,

My system has been ordered from a company based in New Delhi called Sensors India. This is the link to their website -- http://www.sensorsindia.com/

What other detail can I offer you? What specifics would you like to know. Glad to help.

best,
Ashok

little-infinity · Jul 20, 2011

Sorry for the bump, but I was wondering about the feasibility of stovetop C-41.

I have a portable electric stovetop (kinda like a hotplate thingy) that we use when we go camping. An electric range/hot plate of sorts like this.

Basically I plan to put a pot of boiling water and place the bottles of chems in there. Then while I process, I leave the patterson tank in the same pot in between agitations. Will this work? Or will it melt my tank?

Diapositivo · Jul 20, 2011

The heat that those things are designed to produce is probably much more than you would need, and it is maybe not easy to regulate it to the right temperature, consider also the risk of "boiling" your chemistry, melting plastic objects etc.

A food-warmer is probably a better choice, you don't risk melting anything. You then put a basin over the food-warmer (so it must have a flat surface, or be of the kind which is fillable with water) and let the water, tank, and chemicals' temperature stabilize, after which you should be ready to operate safely.

Probably something like that:

http://www.google.com/products/cata...a=X&ei=HSwnTs2iCMP3sgbL1szTCQ&ved=0CD4Q8gIwAw

You can also find Jobo "warmers" quite cheaply on auction sites. They don't have any rotating ability, only keep the chemicals at the right temperature. Something like this:

http://cgi.ebay.de/Jobo-TBE-2-Tempe...der_Entwicklungsmaschinen&hash=item43a80f2360

Fabrizio

olleorama · Jul 20, 2011

Hello, I have said this before, but I hope it will be helpful:

Stuff you need:
*Semi-insulated or insulated container. No need for insulation per se, but makes the whole thing more efficient, I use a cooler chest.
*PID-thermostat, very cheap from china via ebay, or expensive thru your local industry supplier
*PT100 sensor, as above
*Depending on the pid-thermostat you might need a relay, best is a solidstate relay
*Heating element (I use a 300W travel immersion water heater)

This gives you a very consistent setup for little money. Mine cost less than $50 bucks. And it's self calibrating and extremely adaptable. Could be used for a large tank for huge RA4 printing drums, or a small thing for doing single rolls of 35mm.

hpulley · Jul 20, 2011

Don't overheat C-41! I once did a pre-soak at 50C or so and ended up with red spots (in reverse) so it looks like I damaged the emulsion.

little-infinity · Jul 20, 2011

Really? Yeah I wasn't intentionally going to do so. Maybe the lowest setting will give me the right temp?

It says I can control the temperature using a knob. I'll do a test to see what temp the lowest setting gives me to be on the safe side. Thanks for the heads up!

brucemuir · Jul 20, 2011

I dot lose much temp over the 3:15 time for C41 but E6 can drop enough to cause problems.

I monitor closely and stick the tank in the bath between inversions.

I testing a pull for E6 right now on some expired EPP.

Athiril · Jul 20, 2011

ashokgoyal42 said:
How does one control the temperature for the crucial developer process in C41?

I've been heating the Patterson film holder so that the heat doesn't dissipate but despite that when I pour the developer at 39 degrees - it shows 37 within a few seconds.

Should I set the developer at 40C and then let it fall to 38? Any ideas?

Depends on your ambient before presoak, I was using ~44c and it would drop to 38c.

I just use 45c+ water presoak, agitate so heating is even, check temp is ~40c, check dev is right temp, pour out water, pour in dev, go for 3m 15s, negs using replenished flexicolor come out fantastic.

In a patterson tank with ~14c ambient temp I haven't had a temp drop, nor with 6min Kodak E-6 (replenished), if you're worried, just a water bath in the sink shall do.

Beware using steel in a water, any temp change in the sink will translate to a change in your tank.

brucemuir · Jul 20, 2011

I just finished my run of e6
ambient is around 74f in processing area
Paterson plastic tank and reels
water bath at around 108 to start and let drift down to 104f

I tempered critical solutions to about 102-104 and kept an eye during the entire 5:45 1st dev time (slight pull tests to control a magenta shift in expired EPP)
Presoak at 104f drifted down to 101-102 at first.

It was pretty easy to keep the temp right around 101f. (you can check the patterson tanks throughout)

The plastic tanks may be the way to go for E6 although I almost exclusively used stainless for C41.

Gerald C Koch · Jul 20, 2011

This is a situation where metal tanks have an advantage over plastic ones. They come up to temperature in a few seconds. A cheap styrofoam cooler works well as a water bath. The time in the developer is so short that there is little chance the system cooling down appreciably. I never use a presoak as it is unnecessary for metal tanks.

Temperature control in C41 - manual process

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