ISO and C41 ?

[VincentM]

Hello,

Im used to B&W development and I will try soon C41. One thing is troubling me though: nowhere I read about ISO when developing C41... Does it change development time Whether I have 200 and 400 films?

My second question is what shall I do when I shot a C41 expired film rated at 200iso one stop underexposed ie: 400iso? Shall I develop longer ? 3mn30s?

Thanks

 

[Sirius Glass]

+1 What Greg said is exactly right.

Steve

 

[2F/2F]

Hi,

C-41 is a standardized process, as is E-6. That means that the film makers design films such that they work with a process that is set in stone.

The amount to add for a push will vary from emulsion to emulsion. Kodak Portra 400 and 800 follow the 30 seconds per stop for the first two stops rule. Others may vary, though those are good starting points for experimentation. And those were times for the old Portra 400 (VC and NC), which has now been replaced, so I don't know if new Portra 400 follows the same pattern. Not every film is equally sensitive to pushing, so make sure you experiment if you plan on doing that often.

 

[VincentM]

Thanks guys great info. I m now ready to start

 

[Sirius Glass]

Think about it. You see film development in Costco, Walmart, ... they just add one roll of color film after another without bothering to check the type.

Unfortunately this is not true of black & white film. Each film type has its own development times.

Steve

 

[hpulley]

Yes, makes you understand why they went for Chromogenic B&W films. Processing many different types of B&W film was a royal pain for them...

Makes me wonder why there is such mystique for home C-41 development. One time, one temperature, one developer, so much simpler than B&W in many ways!

 

[Sirius Glass]

Yes, makes you understand why they went for Chromogenic B&W films. Processing many different types of B&W film was a royal pain for them...

Makes me wonder why there is such mystique for home C-41 development. One time, one temperature, one developer, so much simpler than B&W in many ways!

I put it off because I did not have a good way to maintain the temperature.

Then I got a Jobo processor and tanks.

I bought two boxes of 1 liter Unicolor chemicals.

I waited to collect enough color film to make the processing worth mixing the chemicals.

I kept reading here that it was easy to do. Still did not have enough exposed film.

After a year I came back from a trip and with the exposed film in the refrigerator, I had enough film.

Spend a day figuring out which films I could afford to loose if the first batch screwed up.

Divided up the film. I mixed Ektacolor 100, UltraColor 400, Vivid Color 400, ...

Worried.

Mixed the chemicals, loaded the tanks, and waited for the temperature to stabilize.

Processed the first batch of four rolls. They came out with the rinse water purple and the film purple. I posted on APUG. Back into the tank and rinsed many more times. The film looked good. Figured out that each two minute rinse really meant four 30 second rinses. Back at APUG others said yup that is right.

In the end I did four batches of processing in about 12 hours.

It was easier than I thought. Even easier than black & white.

Now I am going to spend some quality time shooting black & white with my 4"x5" Pacemaker Speed Graphic hand held at the Andrews AFB open house this coming weekend.

Steve

 

[2F/2F]

That is interesting. The rinse times are 3:15 at 15 to 105 F in the C-41 process I know (one after bleach and one after fixer).

 

[Sirius Glass]

At 100.4º F or 38º C for Unicolor C-41
3:15 Developer
6:00 Blix
2:00 Rinse
2:00 Rinse
30 to 60 seconds Stabilizer

Right of the instruction sheet.

 

[Athiril]

It's +15% stop consecutively, as opposed to 30 seconds, which equates to 30 seconds for the first two, but not exactly. After 2 stops, it needs more than +15% imho.

 

[Sirius Glass]

I ended up doing 12 rinses instead 8 rinses just to be sure.

 

[hpulley]

The JOBO/Unicolor 1L kit lasts longer than a day! You don't need to save up so many rolls. I saved up 9 rolls the first time I used a 1L kit just in case but that one lasted for 24 rolls over 4 months! So the next batch I mixed up and processed 4 films, then 1-2 weeks later, 4 more films. Then 1-2 weeks later, 3 films... The stuff lasts much longer than the instruction sheet says.

I do 3 rinses, then stabilizer. With just 2 rinses I find there is still some pink in the water so better one more rinse I thought.

 

[Sirius Glass]

I did 4 rolls of 120, 4 rolls of 120, 2 rolls of 120, and six 4x5s. That is equivalent to 11 1/2 rolls. The instructions state that the kit is good for 8 rolls but with caveats that 25% or 50% more can be processed. Further it recommends that the processing be done in three days for best results.

One of the sales persons at FreeStyle recommends no more than 12 rolls per kit.

I am interested to hear what others got out of the 1 liter Unicolor C-41 kit and still got good results.

Steve

 

[Athiril]

12? Even 8 is a lot.

I go like this pre-soak to get up to temp -> C-41 Dev -> Bleach -> open tank and rinse reels with 100-200ml water, tip out -> Full Rinse/Wash, plunge reels up and down -> Fixer -> Same thing with the 100-200mL -> Same Full/Rinse Wash again -> Let soak in water (same temp as dev btw +/- a few) for 5 min, it'll come out pink -> Soak Stabiliser III for a few min.

Though I am using Flexicolor.