C41 Developing at home question

Peter De Smidt · Oct 6, 2005

Hi Folks,

I'd like to do some C41 developing in my Jobo CPP-2. I've bought the various Kodak Flexicolor chemicals, and I have a question on storage. I seem to have two options. First, I could mix up the whole batch of developer (1 gallon) and store it in small glass bottles, using a whole bottle each time I process film. Second, I could mix up fresh batches by using the appropriate amount of the concentrated solutions, with the idea being that the concentrates should keep better than a mixed working solution. Years ago, I used the latter process successfully with Flexicolor developer for developing Tech Pan. The problem with this is that total chemical contents aren't listed, and so I'd have to measure them, (which wouldn't be that hard.) Which method would you recommend?

jd callow · Oct 6, 2005

If you store it as you suggest I still wouldn't mix up any more than you'll use in a month.

Photo Engineer · Oct 6, 2005

I have done what you suggest and it works.

There is one minor problem. The first time around, you must pour out the chemicals to measure the quantity, and this aerates the developer portion of the chemistry (the stuff in the glass bottle) and so your very first batch of remaining concentrate will keep more poorly than subsequent packages that have never been poured out and then back into their original bottles.

Otherwise, it works just fine.

PE

Peter De Smidt · Oct 6, 2005

Thanks Guys. Kodak says that mixed working strength developer will last 2 months in full, tightly capped glass bottles. My guess would be that opened concentrate would keep a little longer, especially if I keep the concentrates in the fridge. But as Mr Callow suggests, I'll have to be careful. I mainly plan on developing XP-2 Super, but I'll also do some 4x5 Fuji Pro 160.

Another question: various sprays are available to extend the life of oxygen sensitive liquids, like wood finish.... However, these sprays are fairly expensive and somewhat of a pain to get. Most "dust-off" type of sprays seem to be some non-oxygen gas. Would spraying a small amount of Dust-Off into the bottle before capping be a good idea? Someday I'll probably pick of up cylinder of argon or nitrogen, but I just can't justify the expense at the moment.

Photo Engineer · Oct 7, 2005

All I can say is that nitrogen works, but then full bottles that are oxygen impermeable work also.

I have kept RA color developer for 6 months mixed to working strength in full plastic Jobo bottles (1 L) and 3 months in full 5 L bottles. The Jobo bottles are very robust and air tight.

C41 color developer has kept more poorly for me than the RA paper developer under identical conditions.

PE

jd callow · Oct 7, 2005

PE,
I have c41 tanks (wing-lynch) which use nitrogen in the air space and maintain the chems at temp. What would be your best guess for how long they will remain good?

Photo Engineer · Oct 7, 2005

Mrcallow, I have no idea. I can say this though. Keeping the developer at working temperature shortens the lifetime somewhat over room temperature storage.

Replenishment extends lifetime due to adding fresh sulfite and hydroxyl amine from the replenisher. They are both essential to color developer stability. Since I can get several months in closed containers under nitrogen at room temp, I would assume you could too, but that is no guarantee. A capped bottle leaks less than a lidded tank.

I eyeball my developer and toss it when it gets to about a cola color. I usually test it with a strip of leader as well. The RA developer makes it for over 6 months (see above), but the C41 will not do as well. IDK why. They are both carbonate based and use HAS as stabilizer, but one is CD3 and the other is CD4 which is slightly more reactive. Maybe that is the reason.

PE

Peter De Smidt · Oct 7, 2005

PE,

Thanks for your help. What kind of life are you seeing with the C41 developer? If I can get 3 or 4 months in tightly capped, full, refridegerated glass bottles; then I won't bother with measuring out small amounts of the concentrated solutions.

-Peter

eumenius · Oct 7, 2005

It's quite easy to divide the whole kit (I assume it's dedicated for minilab use, like the ones I get here?) between small bottles, each aliquot enough to make a volume of working solutions enough to fill your machine. I prefer to use small soda PET bottles - they have good screw-on caps, are airtight, and allow to squeeze out almost all residual air before closing. For smaller volume it's convenient to use large syringes (make sure they are full plastic, without rubber on plunger). But it's definitely a bad idea to keep color developer in half-full bottles. In return, the aeration is a must for bleach-fix mixture - it's essential for its activity (at least in modern mixes based on EDTA/Fe3+).

Cheers from Moscow,
Zhenya

Photo Engineer · Oct 7, 2005

I can get about 3 - 4 months in capped Jobo bottles which seem to be very oxygen resistant. I do put a nitrogen blanket over partially full bottles though. I divide one gallon up between 4 1 qt (liter) bottles filled to the top otherwise and put the cap on tightly. I use clear bottles so that I can judge the color change to the developer. There is no need to use dark bottles in a darkroom. There is not enough light, normally, to harm the solutions. All of my processing is done one-shot with the developer being discarded after use.

Normally, you should NOT refrigerate any photographic solution, as it could crystallize out or 'oil out' with organic chemicals becoming insoluable. If that happens it is sometimes difficult to redissolve the chemicals. You can often only do it by using a hot water bath for fairly long time with stirring, and this only aerates the solution.

Only an actual test will tell if any harm is being done by refrigeration and any treatment to redissolve any crystals or oils that may form. If an oil forms, it may be quite damaging to the solution, as the oil is probably not properly protected from oxidation.

PE

gbroadbridge · Oct 8, 2005

Peter,

Mostly the solutions used for C41 process are a lot more resilient then the packaging and technical data would suggest.

I routinely use 500ml of AGFA C41 chemistry that is supposed to survive for 5 x 120 or 3 months for 8 x 120 or 6 months. I simply mix with distilled water, heat to process temp, process, then let cool to room temp until needed next. I do shoot a squirt of butane into the Jobo 600ml bottles before recapping to remove oxygen that is not in the solution - the rest just oxidises I suppose.

I can never see any difference between the first and last roll, although I suppose a process control strip might tell a different story.

Same with RA-4, but that stuff never dies, just a squirt of new to replenish and it'll keep going forever

Try it

Graham

Peter De Smidt · Oct 9, 2005

I just developed my first two rolls of 120 XP-2 Super through C41. While the negatives are still drying, everything looks good.

In doing a little research, there seems to be some question about how much developer is needed per roll, both to cover the film in the Jobo tank, and to properly develop the film. According to Kodak's most recent bulletin, 1 gallon of the flexicolor will only develop 11 rolls of 120 film, whereas some on Photonet claim being able to run twice as many films without a loss of quality. Any opinions?

I developed two rolls in 500 ml of chemistry all one shot in a Jobo 1500 series tank that'll fit three 1501 reels in the 120 size. I used two seperate reels, and thus the film was only in the outer edge of the reel. I've not had any luck loading two 120 films onto the same reel. In fact, I find loading these plastic reels with 120 film to be a pain, whereas loading the Hewes SS reels was no problem whatsoever. Unfortunately, I don't have the appropriate stainless steel rod for the three 120 reel tank.

In any case thanks to everyone who offered advice.

gbroadbridge · Oct 10, 2005

It's a lot easier than some would have you believe, eh

I'd suggest you do your own tests to determine the life of the solutions.

I always completely fill the jobo tank, as on one occasion when using the minumum required according to the tank I ended up with a partially developed film. The chemistry was getting quite old (5-6 months) so was losing activity, but running a test strip immediately through the system with the tank full showed it still worked, it just needed more developer

Graham

ErinHilburn · Oct 10, 2005

Student Photographer with ???'s

I am studying photography in school and we have been forced to go digital for portrait class, I've found its not to my liking at all. We took b&w and the teacher (luckily) made us learn in the darkroom developing our own film and prints. The problem is he gave up a long time ago in teaching the development of color prints and film(preferably slide film) so I've taken a colorslide class but never developed my own. I would like to learn this process and use it myself and hopefully evade the digital onslaught, is there any books or materials you could suggest that I could learn these things from?
Thanks,
Erin

Photo Engineer · Oct 11, 2005

Erin, there is a Kodak color dataguide book with lots of information on E6 and C41 processing. It also has a section on RA processing with printing examples.

You might find it useful.

PE

srs5694 · Oct 11, 2005

Tom Grimm's The Basic Darkroom Book, 3rd Edition (Plume, 1999) has chapters on color processing, as well as on B&W, that cover the basics. If you buy a complete C41 or E6 "kit" from Paterson, Tetenal, or the like, it'll come with basic directions that should get you through the process, although these instructions won't cover all the finer points and theory behind it all. My experience is that if you buy chemistry in non-kit form (separate developer, bleach, fix, etc.), you won't get as much in the way of manufacturer instructions, although they may be available on the manufacturer's Web site.

Note that the details differ from one manufacturer to another, so be sure to check the description that comes with any kit you buy. It may require slightly different times than would be mentioned in an unaffiliated book, Web site, or whatever.

ErinHilburn · Oct 13, 2005

Thank you I really appreciate it.

C41 Developing at home question

Peter De Smidt

jd callow

Moderator

Photo Engineer

Peter De Smidt

Photo Engineer

jd callow

Moderator

Photo Engineer

Peter De Smidt

eumenius

Photo Engineer

gbroadbridge

Peter De Smidt

gbroadbridge

ErinHilburn

Photo Engineer

srs5694

ErinHilburn

C41 Developing at home question

Moderator

Moderator

Privacy & Transparency

Privacy & Transparency