C-41 reuse

[Bruce Osgood]

almost embarrassed to ask but I just processed my first roll of color with Unicolor kit and can't find out if you're supposed to toss it out as one-shot or return it to the container and draw off what is needed for the next roll(s)?

I read where people are getting 12 or more rolls from a liter but at 8oz per roll that can't be done. So I assume you return it to the original container and reuse it?

 

[Wade D]

I was just looking in to getting one of those kits from Freestyle. Their ad says when reused you can get 8 36 exp rolls from a 1 liter kit. I was just going to start a thread about it when I saw this thread. Are you happy with the way the negatives turned out? The process looks pretty easy, was it?
Thanks,
Wade

 

[hrst]

You can reuse. There should be instructions for addition of time for developer, but it isn't very much (as C-41 is quite sensitive to developer time changes), a few seconds per roll per liter.

One-shot is recommended for extreme repeatability but there's nothing wrong in reusing with time increase, it is an approved way to process. The deviations from the standards are low, probably lower than with most minilabs. Very well maintained prolabs are different and if you want to get the same level of quality, you should do one-shot and carefully control time, temperature, agitation, solution injection and drain times etc. In that case, the Unicolor blix kit is not recommended anyway, so just reuse, save money and be happy...

It is up to you whether you want to take the smallest possible volume (240 ml?) at a time and reuse it fewer times with greater time increases per roll, or mix the used developer in larger amount of "working solution"

I tend to use 500 ml as a working solution and reuse it up to four to five times, or even more if I don't need guaranteed results. The reason I use more than ~250 ml is that I want to have enough working solution for the cases when I want to develop more than one roll at a time.

 

[Ottrdaemmerung]

I've used Unicolor kits. Yes, you pour the developer back into your container and re-use. About hrst's comment above: the Unicolor kits don't specify extending the dev time after each successive roll (or ever), but you'll still get good results. I've gotten around 14 rolls from a 1 L kit, but make sure you stash a few rolls to be developed so that you can do them mostly all at one time: once mixed, the chemicals only last about six weeks and I wouldn't even trust them for a month.

 

[Bruce Osgood]

Thanks all.

Wade.
The only problem I've found after two rolls is with the appearance of residue after the film has dried. The probable cause offered by Unicolor is Improperly washed 5247 films and their solution is to remove ALL carbon jet backing during final rinse. I have no idea what 5247 films are (I'm using Kodak Gold 200 as a learning film) but I suspect my 3 minute wash in running water before stabilizing is not enough. Next roll I will double the rinse time.

Other than that, I would use the Unicolor kit again but I would like to try the Tetenal C-41 kit next. The process is a breeze.

My next step will be, as Ottrdaemmerung suggest, to collect a few rolls and process as one batch.

Thanks again for your responses, it has been a great help.

 

[MattKing]

Bruce:

5247 is/was one of the films intended for cinematographic applications. It has/had a "remjet" backing that needed to be scrubbed off the film as part of the process.

 

[Bruce Osgood]

Bruce:

5247 is/was one of the films intended for cinematographic applications. It has/had a "remjet" backing that needed to be scrubbed off the film as part of the process.

So, I guess 5247 is not the problem here. Do you think additional wash time will solve my spotting or is it something else again?

 

[hpulley]

I mixed a batch of JOBO/Tetenal/Unicolor 1L dev, blix and stabilizer in January. I developed 24 rolls from then until last week (four months total, kept in cold storage when not in use) when the developer finally became exhausted (luckily I clip tested so as not to ruin film). I mixed up a new batch and am already 4 rolls of Ektar 120 into it, works great but you MUST re-use it to get more than about 4 rolls developed in 1L.

What kind of spotting are you getting, can you post a sample? Could your water be too hot? I used hot water, around 50C on one roll early on and it had red spots from the emulsion being overcooked. Keep it to at most 40C as per the instructions and it should be OK. Or are you getting milky white spots from the stabilizer/drying aid?

 

[Bruce Osgood]

Or are you getting milky white spots from the stabilizer/drying aid?

Exactly, you've nailed it! Now what causes it? You suggest Stabilizer/drying aid. I haven't used a drying aid so I'm left with Stabilizer. Have I perhaps not washed long/aggressively enough in running water prior to Stabilizer. The instructions indicate 3 minutes at 95-105F which I did. I didn't do any rinse/wash after Stab. Just hang and dry.

Additionally, the spotting does not appear on the emulsion side but on the film base side.

 

[hpulley]

You don't wash after stabilizer, you need to leave it generally. The stabilizer already includes a drying aid. I assume you mixed it as per the instructions, very simple: just dissolve the stab packet into 1L of water.

How dry is it where your film is drying? How are you hanging the film? I find if it dries too quickly, before the water drops have a chance to drip off it can be problematic. Used before the spots dry completely I find cotton darkroom gloves and my breath on the base side only can be used to wipe the spots off but once they dry completely you may need to re-stabilize to get rid of them.

At what temp are you using the stabilizer? It should be room temperature.

 

[Wade D]

I'm very encouraged by the ease of development. 40+ years ago things weren't so easy so I stuck to B&W. I have 40-50 rolls of Kodacolor and Fujicolor hiding around here that go back at least 10 years or so. I think it will be very cost effective to develop them myself. I might try 4x5 color also. My darkroom is well equipped to handle that size for developing and printing.
The next step will be printing with RA-4 but that will be another thread.
Thank you all for the great input!

 

[2F/2F]

I do not know about Unicolor, but you can get 16 rolls out of a quart of Kodak developer if you add time after every four rolls, and do them all within six weeks of making the chemicals. (1st time 3:15, 2nd time 3:23.) I never take it all the way to the fourth run through. I use the first two for "important" stuff, and the third for less important stuff (snapshots, cross processing, etc.). There couldn't be that much difference between the developers in the Unicolor and Kodak kits.

 

[hpulley]

Since it is a real Stabilizer you can do the old films with this kit. Newer kits with Final Rinse instead are not enough for old C-41 film.

 

[Ottrdaemmerung]

About that spotting: I've gotten the same exact spotting from the Unicolor kit. (I don't have access to Tetenal and haven't tried other kits, so I don't know if the spots occur with them.) I've tried mixing a couple of drops of Photo-Flo into the stabilizer upon mixing it up, which helps. Or, when you find you've gotten the spots, moisten a small sponge with stabilizer and wipe down the non-emulsion side to remove the spots. But whatever you do, don't moisten the sponge with Photo-Flo like you might do with B&W film: on C-41 film the Photo-Flo just seems to make a "greasy" coating that just stays on top of the film.

 

[Chris Douglas]

Works well here too

I use the Unicolor kits too, and they are very consistant. I add 5 seconds to the developing time per roll of 36 exposure or 120 film. For the 24 exposure rolls I sort of guess a little less. I have no trouble getting twice the rolls the instructions suggest.
For consistant results you need to control temperature. I use a thermostatically controlled bath with a pump to move the water around the tank and bottles. Actually it is just a plastic dish pan, but temperature is very constant at 100 degrees F. I also had trouble with spotting. I add photo flo 1:500 and hang the film at a 45 degree angle with the edge down, no squeegee. No more spots!

 

[brucemuir]

Did you use distilled water to mix stabilizer?

 

[Chris Douglas]

Yup, always distilled water, but there must be no surfactants in the stabilizer cause it beads up on the film and won't run off. I don't squeegee film so I had to do something to get the water to sheet off.

 

[hpulley]

The stabilizer should include surfactants.

 

[Роберт]

I use this set up for my C41 development:
Jobo CPA-2 with elevator, 2523 tank (minimum 270ml volume in rotary) and two 2502 reels.

The tank takes 270ml in rotary. I use Fuji Hunt C41 chemicals. C41 developer in 3 parts A+B+C plus a starter, seperate Bleach and Fix and a Stabilizer (indeed containing also a wetting agent).

In this way a piece of cake to maintain the developing temperature of 37,8C +/- 0,5.
I am using the chemicals in one shot but for a 250ml mixture I add extra 10%-20% water (so an end volume of 270ml-300ml). The whole system is very reproducible.

If a large amount of Fuji Hunt chemicals is too much: The same chemicals are sold under Rollei Digibase C41 as smaller kits, incl. everything like syringes etc. It's exactly the same stuff!

 

[tbeaman]

I don't think it actually does. I could swear I read that here somewhere. In any case, I am sure I read here that it was okay to add Photo-Flo, so that's what I've been doing. Haven't had any problems.

 

[2F/2F]

Old films need Stabilizer for a specific ingredient that is not related to wetting agents. Adding Photo-Flo to Final Rinse will not make it suitable for older films. Photo-Flo can be used, along with other ingredients, to make Stabilizer from scratch, however.

 

[hpulley]

Old films need the hexamine, formeldahyde etc. as a preservative, otherwise they fade. Newer films don't need it, it is built into the base so Final Rinse can be used instead.

 

[tbeaman]

Sorry, I should have specified I'm talking about the Hexamine based stabilizer in the powder press kit. That's the one that I believe (PE said?) contains no drying agent, and is safe for it to be added to.

On another note, I haven't figured out what works best yet, but it seems you do have to be careful when adding time during reuse. If you consider that 15 seconds equals a one-stop push, I'd almost say it's better to err on the side of adding too little time, especially if you're overexposing anyway. I say that because I think I was adding too much time at first, and some of my negs from the first kit came out too dense. I think I was adding something around 15 seconds every four rolls. I think it's safe to say that it's not necessary to add any time at all until you've done at least eight rolls, since the instructions for the (1L powder) kit don't mention adding time within it's expected capacity (of eight rolls).

I'm still trying to decide what to try with the next kit. What have any of you worked out?

 

[hrst]

If you consider that 15 seconds equals a one-stop push

Of course you can consider that, but it isn't true. Generally, 30 seconds is considered as one-stop push.

 

[tbeaman]

I knew there was a reason I don't generally speak up in these discussions. Thanks for the correction.