C-41 kits and the process in general

[Chris101]

Thanks. I will remember that. Gloves are probably a good idea, especially since my hands crack quite badly in the dry winter here. I have some goggles that I use for soldering, so perhaps I should get them out of the closet.

My hands crack easily as well. I use nitrile gloves because they are cheap and easy to get on and off. Plus they are VERY chemically inert.

If you ever splash, goggles are a good idea. In fact, we have a state law that says I MUST have my students use goggles whenever they use chemicals. So I do, but just between you and me, I never use them unless I am using a caustic solution (like rodinal.)

 

[Fotohuis]

The times for all C-41 films is the same: 3:15 minutes but the capacity of the kit will be less if you're using iso 400 films or higher.

Further a Stabilizer should be supplied. If not you can use a wetting agent + a very small amount of Formalin in the last bath. This type of Stabilizer is also succesfull for E-6/C-41 films before 2002. 27ml of 37% Formaldehyde in 1 ltr. gives exactly a 1% Formalin solution. Unfortunately Formalin is a pretty crappy stuff.
For a good stabilizer you can use 0,5%-1% solutions of Formalin in destilled water with the minimum subscribed addition of the wetting agent.
If not using a good Stabilizer your E-6/C-41 film, not used color couplers, will give after 5-10 years a destruction of the negatives, apart from the risk of bacteria grow.

 

[kiss-o-matic]

I think this kit handles things slightly different than normal C41 kits. First of all, it's 3 bath, and everything is premixed (hence, ready-use). There are multiple temperatures you can use, and different times.

C41 Softpack is a new concept in colour negative film processing. Each one of the three component parts of the kit - developer, bleach and fix is pre-diluted in 385ml packs which are ready for immediate use and come in a unique air-tight pack. This lengthens the life of the chemical and means they can be re-used on multiple occasions. Each pack will process an individual film or up to a total of 10 in any combination. Processing can take place at any temperature between 20 and 45 degrees C making this the most versatile (and cheapest) film processing kit ever. Individual replacement component are also available when needed.

As per here.

From the instruction sheet:
37.8C 3:15
45C 2:00
30C 8:00
25C 13:00
20C 21:00

It mentions nothing of film speeds in the least, so I guess I should assume box speed. I've got at least 1 roll I want to push a couple of stops though. It's Provia 400x so it's not the cheapest test roll. 🙂

 

[Fotohuis]

The regular temperature is 37,8C/100F. Any deviation gives a color cast because the color couplers are not exactly reacting in the same way. For RA-4 printing a problem. For scanning, less or no trouble.

Provia 400X is a slide E-6 film and not suitable in any C-41 process, unless you want to do cross processing with fancy colors but then you can better use expired and the cheapest E-6 slide film you can find.

This Digibase C-41 kit is pre-mixed so always less storage time then any concentrated version. But it is very easy in use because all C-41 developer components are already pre-mixed.

 

[zauhar]

My instruction sheet says 3:30 for the time, but listen to the advice above and reduce it ; in fact the last time I used the kit I reduced to 3:00 and got negatives that were less dense and had more range than I had seen in the past.

Don't know if this was suggested above, but if you are using a two-reel tank, put 600 ml of developer and blix each in one bottle, and reserve the remaining 400 ml in separate storage as replenisher. After 8 rolls or so I mix the fresh 400 ml with 200 ml of depleted chemical.

Regarding storage, I think it is better to store in a conventional plastic bottle and squeeze the air out before tightly capping, as opposed to using the accordian bottles. In my experience they don't stay 'squashed', I am not sure if that's due to evaporation of chemical into the bottle or air leak, but in any event the simple plastic bottle stays evacuated, and that's all you need.

Randy

 

[Fotohuis]

accordian bottles. In my experience they don't stay 'squashed',

And inside they have a very big surface due to all those ribs. A lot of (air-) bubbles are inside so that the system is not working very well.
Glass bottles is the best due to no diffusion but then you have to use an inert gas for the top. Protectan from Tetenal e.g.
Or accept a little bit diffusion and use PET bottles which have hardly diffusion and can be squeezed easily.

 

[zauhar]

And inside they have a very big surface due to all those ribs. A lot of (air-) bubbles are inside so that the system is not working very well.
Glass bottles is the best due to no diffusion but then you have to use an inert gas for the top. Protectan from Tetenal e.g.
Or accept a little bit diffusion and use PET bottles which have hardly diffusion and can be squeezed easily.

I'm not sure of the specific composition, but I have easy access to Nalgene plastic bottles for lab use, and have been using those. They are pretty flexible, it's easy to squeeze all the air out - and they stay squished!

Re: the accordian bottles, you think it's really air inside, or the reagent going into gas phase? If the latter it is no problem, of course, but I didn't want to bother with the question.

Randy

 

[Fotohuis]

http://www.ucc.ie/fcis/PKplastics.htmhttp://

Here is your answer about Polymers and diffusion.

 

[kiss-o-matic]

Provia 400X is a slide E-6 film and not suitable in any C-41 process, unless you want to do cross processing with fancy colors but then you can better use expired and the cheapest E-6 slide film you can find.

Yep, I know -- I want to see how well it crosses in really dark settings. I figure about half of my developing will be me developing (mainly expired) E6 film.

This Digibase C-41 kit is pre-mixed so always less storage time then any concentrated version. But it is very easy in use because all C-41 developer components are already pre-mixed.

Indeed... I just don't know exactly how long it lasts.

Anyway, I'm still not sure how I would push something 2 stops above box speed... or how I would pull it.

Don't know if this was suggested above, but if you are using a two-reel tank, put 600 ml of developer and blix each in one bottle, and reserve the remaining 400 ml in separate storage as replenisher. After 8 rolls or so I mix the fresh 400 ml with 200 ml of depleted chemical.

I have a 2 reel tank, but this kit is 385ml of each of the 3 chemicals. So, 1 reel at a time only I'm afraid.

 

[mwoenv]

So your first part is to put the film in the tank, fill it with water, and then warm the water externally by putting it in the cooler? If everything can sit in the same tub is there any reason why you wouldn't raise the temperature of the solutions and the film at the same time? I'm sure there's many ways to skin that cat, but figured I'd ask.

No, the first step is to heat the empty tank/reels/films in a water bath. A cooler is used because it's insulated. Use water up to the bottom of the tank lid. If the tank floats put something on top of it to keep it down. Start with water a couple of degrees warmer than 102F (I use Unicolor) and add small amounts of hot water (from a pot of hot water at around 140F) as needed to maintain 102F until the temperature remains constant, i.e., water bath and tank temperatures are in equilibrium at 102F. This usually takes about 30 minutes. Then maintain the water bath temperature at 102F during developing by adding small amounts of hot water as needed. Bring the chemicals to temperature separately. This way you know the chemicals won't change temperature when added to the tank.

 

[kiss-o-matic]

Cool, thanks. Guess I'm cruious why I wouldn't put the chemicals in the same cooler if the idea is that they all need to maintain the same temperature.

Guess I'll need one of those thermometers that has the end that goes in the bottle.

 

[Fotohuis]

When developing on 100F/37,8C each step in push processing is adding 30s for the C-41 developer.

Ready made Digibase C-41 is good for about 3-4 weeks. After this time you have to re-generate the chemicals.
So use 300ml for your tank and keep 85ml for re-generation after 3-4 weeks. In this way you can use this stuff for 2 months without any risk and use up the maximum capacity of the kit.

 

[kiss-o-matic]

When developing on 100F/37,8C each step in push processing is adding 30s for the C-41 developer.

So, if I'm doing 3:15 for box speed, I just do 4:15 if I'm pushing two stops and that should be it?

So use 300ml for your tank and keep 85ml for re-generation after 3-4 weeks. In this way you can use this stuff for 2 months without any risk and use up the maximum capacity of the kit.

I think I'll hit the maximum well before that in this case. I already have like 4 rolls ready to go, and it only does 100 ISO x 10 (I assume I could squeeze out another 1 even).

 

[Fotohuis]

Correct about the +2F push time, however a C-41 film pushing two stops gives quality loss.
The trick of that soft pack packing is to prevent any entry of air (oxygen). Indeed squeeze till the liquid is in top.

 

[kiss-o-matic]

First roll done.

Conclusion: My thermometer sucks. Will be using my good old fashioned mercury one and tossing the crappy digital one I got.

I checked them side by side once and it seemed fine -- did it again, and they were off by a little more than 1C. So, got some magenta.

 

[Photo_Smith]

How do you mean 'magenta' is this after printing? because you can't see the colour shifts in C41 film before printing and then printing itself can introduce shifts.

What film again?

 

[kiss-o-matic]

It was in the scanning using defaults. (I've scanned another roll of this film no problem). I gotta assume something was done wrong (even though it's easy to fix digitally), right?. The film was Kodak ProFoto XL 100.

 

[Photo_Smith]

So it could be the scan?

Default scan settings won't help you evaluate colour balance. When I started colour printing I had a master channel, on top of which I had a chanel for each different make, then each different speed.
Then on top of that I adjusted the film for under and over slopes-took about a day and was done every month.
Auto anything is not a good way to evaluate negatives, colour negative evaluation is almost impossible because of the mask.

The Pro Foto isn't the easiest film to print, there's not much 'pro' about it as its a budget film.

 

[Ronald M]

Chems have a short shelf life after mixing, order of 6 weeks.

Keep stabilizer off the reels if they are plastic , otherwise sooner or later they will not load dues to sticky build up which is impossible to remove.

Soak loaded tank and reels in 100 deg water for 10 minutes before starting or you cool down developer.

Continuous agitation is 2 inversions in 15 sec if you do a hand tank which does work. Did it many times.

Considering how hard it is to get film developed today, you may need to go that route.

Freestyle sells a Tetenal kit.

You will need a accurate thermometer such as a Kodak Process.

 

[kiss-o-matic]

So it could be the scan?

Deafault scan seeting won't help you evaluate colour balance.

It could be, but as per before, I have scanned a roll of this same film done at the lab w/ the same settings, w/ no magenta tinge on any of them, much less all of them. I doubt it was perfect but it was very natural/usable that time, but not this time. I don't think it's the scan.

The Pro Foto isn't the easiest film to print, there's not much 'pro' about it as its a budget film.

Oh, I know -- that's why I used it on the first roll of the kit.

Chems have a short shelf life after mixing, order of 6 weeks.

I'm keeping that in mind. This kit has only been open a couple of days.

Continuous agitation is 2 inversions in 15 sec if you do a hand tank which does work. Did it many times.

Nah, just a hand held. My inversions take a couple of seconds each.

Considering how hard it is to get film developed today, you may need to go that route.

It's a piece of cake here. I can walk to a neighborhood which has 3 very capable labs if you want it done at box speed and in the right chemistry. If you want to push it will cost you, and only two of them cross, and that will cost you as well. I'm working on getting a 5L kit. After shipping, my per roll cost will be down to roughly $1.70 USD.