Colour Comparison: C-41 at different temperatures

drmoss_ca · Dec 18, 2021

Those who have read the thread about a solvent for blix sediment will know I have been tempted back into C-41 development with the promise of speed and ease at room temperature. To be thorough, I have developed colour negative film at 39ºC/102ºF, at 20ºC/68ºF undiluted and diluted 1+5. These comparisons are full strength at 20ºC and full strength at 39ºC. The purple cast and lack of greens in the room temperature version is obvious. These images are the room temp. versions corrected as best as I could manage, but the 39º versions are uncorrected - just as they came out. There may be some exposure variation, as the room temp film was exposed in an F6 and the 39º film in an OM-2n. I need some variety, not being an absolute automaton. I also noticed my current presskit includes times for continuous rotary processors at various temperatures. I think my Rondinax qualifies and will try 90ºF/32ºC next for 8 minutes in both CD and blix. I can get my solutions to that temp in ten minutes, not the 90 minutes it takes for 39ºC (damn Newton's Law of Cooling!)

Room temp:

39ºC

There are more, and I'll add just a few. Clearly, the colours are far better at 39ºC. Eventually, I'll see if they comply just as well at 32ºC and 8/8 minutes instead of 3.5/6.5 minutes.

MattKing · Dec 18, 2021

You need a better test subject!
Clearly this is a test subject for digital, but it gives the idea:

drmoss_ca · Dec 18, 2021

I've got 36 exposures on each. Just hold your horses and wait. There might be a comparison you approve of at some point!

pentaxuser · Dec 18, 2021

Interesting. Isn't 39C nearly 1. 3 degrees C above what Kodak and especially purists say is necessary for perfect development i.e, development at which temperature which is any deviation beyond a fraction of 1 degree C can result in any problem you might describe with C41

What I am trying to say is that unless we believe that anything more than about a small fraction of 1 degree C is fraught with danger we ought to think carefully before raising temperature as the cause of problems.

When we do, all we achieve is to put off newcomers from trying to home develop C41 unless they have the equipment, process controls and sheer determination to ensure that no more than 0.2 degrees C( the figure usually quoted) is exceeded

pentaxuser

koraks · Dec 19, 2021

drmoss_ca said:
These images

...are crated how?
If these are scanned one at a time directly from the negatives, then the actual differences between the frames are virtually certain to be largely obscured by the autocorrection algorithms of the scanner software. Note that these corrections happen outside the scope of user control with all consumer/prosumer scanners; i.e. there's nothing you can do about them.
For a direct comparison, try either scanning both negatives at the same time using a flatbed scanner, capturing both in the same scan, or (contact) print both onto one sheet of RA4 paper using an enlarger.

bernard_L · Dec 19, 2021

koraks said:
...are crated how?
If these are scanned one at a time directly from the negatives, then the actual differences between the frames are virtually certain to be largely obscured by the autocorrection algorithms of the scanner software. Note that these corrections happen outside the scope of user control with all consumer/prosumer scanners; i.e. there's nothing you can do about them.

Vuescan.
Color tab / Color balance /Manual . Freezes color balance but the user still has the freedom to set the black and white points
Technically correct usage would be after setting neutral gray by a right click on an image of a neutral gray card. Missing that, alternate usage would be after using one of the automagic settings on an image with suitable diversity, like the test image proposed by Matt King above. The Santa Claus image in the OP might be unsuitable because of the dominance of red.
@ Matt King. The S* thing is mentioned here only as a tool to evaluate C-41 development.

brbo · Dec 19, 2021

Room temperature stand development -- for C-41?!

foc · Dec 19, 2021

drmoss_ca said:
I've got 36 exposures on each. Just hold your horses and wait. There might be a comparison you approve of at some point!

I look forward to seeing your results.

mohmad khatab · Dec 19, 2021

Excuse me .
Maybe my post is a little far from the main topic.
This is a test I did yesterday with an ECN2 developer that I made with my own hands.
39 degrees Celsius - 3:30 minutes,

Nodda Duma · Dec 19, 2021

pentaxuser said:
Interesting. Isn't 39C nearly 1. 3 degrees C above what Kodak and especially purists say is necessary for perfect development i.e, development at which temperature which is any deviation beyond a fraction of 1 degree C can result in any problem you might describe with C41

What I am trying to say is that unless we believe that anything more than about a small fraction of 1 degree C is fraught with danger we ought to think carefully before raising temperature as the cause of problems.

When we do, all we achieve is to put off newcomers from trying to home develop C41 unless they have the equipment, process controls and sheer determination to ensure that no more than 0.2 degrees C( the figure usually quoted) is exceeded

pentaxuser

OP learning what those of us who have developed lots of color already know. C41 is more forgiving than that in the modern context of developing at home to be scanned or printed in a darkroom. Kodak’s guidance is for a lab making prints in film/print processors.

I fill my kitchen sink with hot water out the tap, drop the chem bottles in, go load film in the darkroom into tanks, and by then the chemicals are up around 42ish. That’s warm enough that the average development temp will be about 40ish. I don’t pay too strict attention anymore to temperature, though I do have a temperature controller that I use if I’m developing a lot of rolls to keep that water warm without runnjng tapwater. Example results for both E6 and C41 are in my media feed color pics.

pentaxuser · Dec 19, 2021

Nodda Duma I agree entirely with your above in #10. My point was that so often I see posters seizing on anything that exceeds these very tight Kodak limits as a likely cause of C41 problems or if a newcomer to C41 asks about the difficulties associated with the process there can be a tendency to exaggerate those difficulties, thus putting off said newcomer when we should be encouraging. This may not be deliberate but that's the effect it has.

As a now "older hand" here ( about 16 years now) I have gotten to know what to expect and make allowances but this probably isn't true of our latest arrivals to film and C41 especially which has this reputation of being almost impossibly difficult to do correctly before they even arrive here at Photrio and to which comments about very, maybe even impossibly strict accuracy so easily add to their existing fears

pentaxuser

drmoss_ca · Dec 19, 2021

I discovered years ago that I didn't need to keep the developing tank in the water bath, it just didn't make any difference. That's why I changed to doing C-41 in the motorized Rondinax (which cannot be immersed). Using plastic measuring cylinders means slow heat transfer, I did buy some glass ones but they are very tall and thin and prone to falling over. It takes me three changes of hot water, which comes out of my tap at 50ºC (once it cools to 43º the change of temperature in the chemicals becomes painfully slow). Once the CD reaches 102/39 I do the pre-wash and then use the developer, adding cold water to the water bath until it cools to 102/39, just so the blix doesn't get too hot. Here's another pair:
20º:

39º:

If I can get the colours of the second photo while processing at 32º/90º I'll be happy. One issue I foresee is that the recommended time is eight minutes, and that might be enough for the solution to cool a bit more than desirable. Only one way to tell...

MattKing · Dec 19, 2021

With these latter two examples, your issues might be due as much to skewing the overall contrast of the negatives as it is to problems with the individual colour responses.

mtjade2007 · Dec 20, 2021

C-41 Processing at a far off from 100 degree F temperature, such as room temperature will result in significant color crossover error. I had been there done that before I eventually acquired a Jobo processor. It is advisable to try to process at 100 degree F as close as possible. Some variation will not ruin your film but try to keep the process at 100 degree F and get the colors right. For shooting natural scenes or portrait of people color accuracy is desired. However, corssover error is OK if you are shooting colorful graphic arts. As long as it is plenty colorful no one will care if the colors are accurate.

mshchem · Dec 20, 2021

I use a microwave to warm chemistry. Very short bursts 5 to 10 seconds at a time. Been doing it for decades. I can be ready to develop in a few minutes. Don't waste precious time, Money etc trying to develop C41 at low temperatures. MHOFWIW
PS I use a dedicated microwave for the darkroom. I think it would be OK to use the kitchen microwave, only if you were quite careful.

drmoss_ca · Dec 20, 2021

mshchem said:
I use a microwave to warm chemistry. Very short bursts 5 to 10 seconds at a time. Been doing it for decades. I can be ready to develop in a few minutes. Don't waste precious time, Money etc trying to develop C41 at low temperatures. MHOFWIW
PS I use a dedicated microwave for the darkroom. I think it would be OK to use the kitchen microwave, only if you were quite careful.

I may end up awarding you a Nobel in photochemistry! That's a brilliant idea. But now I've moved from concertina bottles to brown glass 1l "growlers" from the local brewery, I can't put them in the microwave (metal fixings on the lid), so do my measuring cylinders fit? Nope! Either I saw off measuring cylinders (what's the American name? Graduates?), or I measure and heat in something else. Thinking required (didn't Wol in the Pooh stories say "Thinking requeered"?) Maybe only the CD temperature is critical. Does blix really have to be at 39/102?

I don't take photos of colour charts. Maybe Matt likes orchids?
20ºC

39ºC

mshchem · Dec 20, 2021

drmoss_ca said:
I may end up awarding you a Nobel in photochemistry! That's a brilliant idea. But now I've moved from concertina bottles to brown glass 1l "growlers" from the local brewery, I can't put them in the microwave (metal fixings on the lid), so do my measuring cylinders fit? Nope! Either I saw off measuring cylinders (what's the American name? Graduates?), or I measure and heat in something else. Thinking required (didn't Wol in the Pooh stories say "Thinking requeered"?) Maybe only the CD temperature is critical. Does blix really have to be at 39/102?

I don't take photos of colour charts. Maybe Matt likes orchids?
20ºC

39ºC

My microwave will accommodate 1 liter Kodak graduates. I caution people to be careful. PET bottles will melt, don't try to put any bottles in. The old school Kodak polypropylene graduates work great and come in 1L, 500mL, 250mL sizes. Nalgene makes PMP (polymethylpentene) beakers that you can boil water in a microwave no trouble.

Of course a sous vide on a plastic bucket set to 102°F with the appropriate bottles works great too.

MattKing · Dec 20, 2021

drmoss_ca said:
Maybe Matt likes orchids?

I do:

The problem, however, is that unless you have the original to permit a side by side comparison, you can't get much benefit from using them as a colour check.

Raghu Kuvempunagar · Dec 20, 2021

Colour is only one aspect of C41 development. Does lower temperature processing of C41 films ensure the same sharpness, resolution, grain, and speed as standard processing? And in case of films like XP2 Super, does it guarantee the highlight compensation that this film is known for?

Donald Qualls · Dec 21, 2021

Nodda Duma said:
I fill my kitchen sink with hot water out the tap, drop the chem bottles in, go load film in the darkroom into tanks, and by then the chemicals are up around 42ish.

I can't quite do that, because of my darkroom setup. I load the film first, then adjust my darkroom tap water to the high 90s F using a common bimetal darkroom thermometer, fill a tempering tub with that water, start my sous vide set to 102 F, and plop the bottles into the bath. I then go do something else for forty-five minutes or so. I can't reverse the order because the sous vide has a bright display, and will reliably fog my film.

When I come back, the bath will be up to temp, I'll stick the thermometer in the developer bottle, to verify it's also up to temp, and if it's no, go do something else and come back in another fifteen minutes. Usually that's all I've needed, but in winter it might take more than an hour (the darkroom gets pretty cold even though it has a vent for the central heat).

I don't keep the tank in the tempering bath through the 3:15 developer run, hence why I start at 102 F -- it cools off some while I'm running. Seems to work okay, but I haven't yet gotten to trying RA-4 printing. I may have to modify my process when I do.

Edit: Actually, I do have the option to fill the bath and put the bottles in, then load the film, and sometimes do that -- just don't start the sous vide until after the film is in the tank.

foc · Dec 21, 2021

I know that lower temperature (30C and below) C41 bleach can cause some problems. You may resolve it with an extended time but just be sure you don't have retained silver.

Raghu Kuvempunagar · Dec 21, 2021

foc said:
I know that lower temperature (30C and below) C41 bleach can cause some problems. You may resolve it with an extended time but just be sure you don't have retained silver.

You can use Kodak SR-29 bleach at room temperature without any problems.

Donald Qualls · Dec 21, 2021

foc said:
I know that lower temperature (30C and below) C41 bleach can cause some problems. You may resolve it with an extended time but just be sure you don't have retained silver.

I've used Flexicolor LORR bleach at room temp (~17 C that day) when I tried C-41 stand development. Gave it the same 45 minutes as the color developer, and as far as I can tell, it got all the silver converted so the fixer could dissolve it.

Tel · Dec 21, 2021

Reinhold, AKA "imagesfrugales" over on Filmwasters did some extensive experimenting with C-41 chemistry, dev times and temperatures about 7 years ago. Here's the link to his conclusions:
https://filmwasters.com/forum/index.php?topic=8224.0

Nodda Duma · Dec 21, 2021

Donald Qualls said:
Seems to work okay, but I haven't yet gotten to trying RA-4 printing. I may have to modify my process when I do.

RA-4 can be developed at room temperature using Kodak Ektacolor RA/RT chemicals, as detailed in posts by the late Ron Mowrey here on photrio.

numerous threads on the topic of RA-4 at room temperature. Here is one: https://www.photrio.com/forum/threads/hot-plates-for-water-bath.60626/

Good luck finding the chems with the current supply chain situation, though.

Colour Comparison: C-41 at different temperatures

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