C41 Home kit capacity clarification...

[NortheastPhotographic]

I am about to order a Jobo CPE2, because I have found myself in a bit of a film processing desert. I have some questions about the available C41 processing kits from Arista/Tetenal...Mostly in reference to capacity. So, if I get a a 2523 tank, I can do 2x rolls of 120 or 35 at a time, using 270mm of solution. They say that the capacity of the developer is 8 rolls of 36ex 35mm film. So, does that mean I could take my 300mm of solution and run a full 8 rolls before adjusting time/discarding the solution? Or should each 300mm of solution be treated as "one shot"?

If I could re-use the working solutions I could then get 24 roll of 120 out of a 1qt kit, vs only 6 if I use it all one shot.

Also, in the PDF instructions they mention extension of developing times when re-using, but it's unclear to me if this is in reference to after you meet the 8 roll listed capacity, or each time you re-use the solution.

Thanks for your help in advance!

 

[Peltigera]

If they say that the capacity of the kit is 8 rolls, that will be for the kit, not each 300 ml. Your quart is going to be less than a litre - you won't process 24 films in that.

You say your tank's capacity is 270 ml and then talk about using 300 ml. If you stick to the 270 ml, you will process more films for your money. There is no benefit in over-filling the developing tank.

 

[Pioneer]

I typically get 50% higher capacity from each kit so I expect 12 36 exposure rolls from the 1 quart kit.

To get that increased capacity I use distilled water for mixing and do all my developing within a few days.

Additionally, if I am mixing film formats I calculate my development by square inches, not by number of rolls. For example, I actually can process 20 rolls of Fuji Superia 200 in 24 exposure rolls. If I mix some 4x5 in with a couple 36 exposure rolls of Ektar and the rest is all Fuji 24 exposure rolls then I write the number of square inches of each developing session on the bottle. When it adds up to 120 square inches or so, then the developer is pretty close to exhaustion.

And yes, I increase the development time every so many square inches as I go along, not after after I have exposed 8 rolls of 36 exposure film.

Hope this helps a little.

BTW, I love my little CPE2 but I have to be careful to keep the total solution in the tanks below their recommended minimum or that poor little motor starts to struggle. As a result I rarely use my 5 reel (35mm) tank but stay only with the smaller two reel tank.

 

[klownshed]

I use the Tetenal C-41 rapid kits and they are not one shot. You mix up 1litre of Dev, blix and stabiliser and then use the required amount in your tank. Then pour it back into the 1l container.

After every few rolls you up the times as per the instructions.

They are rated at 16 rolls of ISO 200 or less or 12 rolls of 400 and greater.

I usually get about 24 rolls out of a kit before noticing any issues.

I use the stabiliser in a different container though and take the film off the spools as the stabiliser is hard to wash off the spools. I noticed the next time I used the tanks after stabiliser was the last thing in them that I'd get foam in the tank, even after wAshing everything well. Obviously not well enough!

Anyway, since not using stabiliser in the tank that issue has gone away.

I use a CPE2+ With the 1520 tanks and get pretty good results with Tetenal.

 

[Berri]

I use tetenal 1L kit and get 14 rolls mixing 0.5L at time and processing 7 rolls with each half liter re-using the same solution.

 

[Storm Image Studio]

I use tetenal 1L kit and get 14 rolls mixing 0.5L at time and processing 7 rolls with each half liter re-using the same solution.

The small issue with mixing only parts of powder kits, is that you can't be sure you are getting an even distribution of all the component chemicals in each portion. Which in turn can lead to uneaven/unpredictable processing.
If you really wanted to split the kit into 2 x 0.5l I would suggest you do the split after you've mixed up the 1L and store in 0.5L airtight containers.

 

[afriman]

The small issue with mixing only parts of powder kits, is that you can't be sure you are getting an even distribution of all the component chemicals in each portion. Which in turn can lead to uneaven/unpredictable processing.
If you really wanted to split the kit into 2 x 0.5l I would suggest you do the split after you've mixed up the 1L and store in 0.5L airtight containers.

I'm sure he's referring to the liquid kit, not the Press Kit. I believe the liquid kit is now only available in a 2.5l size - so it's also it conveniently divisible into 5 x 0.5l.

 

[Storm Image Studio]

I'm sure he's referring to the liquid kit, not the Press Kit. I believe the liquid kit is now only available in a 2.5l size - so it's also it conveniently divisible into 5 x 0.5l.

Ah yes, there is that possibility

Still, I am a fan of mixing whole and storing in parts if needed. I have been unlucky in the past after opening the developer to part mix and the unmixed portion went off pretty quickly.

 

[Berri]

Ah yes, there is that possibility

Still, I am a fan of mixing whole and storing in parts if needed. I have been unlucky in the past after opening the developer to part mix and the unmixed portion went off pretty quickly.

yes I use the liquid concentrate. Here in EU is available in 2,5L and 1L. E6 only 5L or 2.5L. The liquid concentrate has a longer life, I also use gas to protect it from qxidation. It last quite a long time

 

[Sirius Glass]

The tanks should have the minimum and maximum fill limits on them. Also those are published by Jobo. I would scan them and post them but they are not with me at this moment [when I am posting this, not necessarily when you are reading this].

 

[trendland]

I agree with Pioneer.
The capacity of the new tetenal Kits
is really much higher than one will expect.

For example : If you use a working solution with is aged (concentrated)
5 weeks - you suspect the capacity that
Tetenal gave you when you bought it.

This is even the case when you have bought a kit witch stands round about
5 years in the room of your lokal Dealer.

If your kit is realy new (nearly produced
in 2016) the capacity is even higher than
+ 20 , + 30 % i would say.

This is even the matchpoint if you try other temperatures (lower) or other
dillutions.

You have to find out where the border
of capacity could be.

Always using Test Films or parts of them.

with regards to you

 

[TattyJJ]

I have noticed the tetenal kit gives two different options for temp. Is there any real benefit for using the lower temp, any increased capacity etc?
I'd be interested in knowing how to really get the maximum number of films from a kit.

 

[Berri]

I have noticed the tetenal kit gives two different options for temp. Is there any real benefit for using the lower temp, any increased capacity etc?
I'd be interested in knowing how to really get the maximum number of films from a kit.

I always work at 100F, but as you say, Tetenal gives instructions for processing at lower temperature. I think it depends on what equipment you have available but I don't think a lower temperature would make much difference in terms of life span of the product. Some might say that a higher temperature would increase the oxidation, but it would be difficult to say how much.

I think your best option to get the most out of it is to use a pre wash, a stop bath after developer and use brown glass bottles filled with neutral gas. Also process more films at time will help a lot.

 

[Berri]

With this workflow I get 14 rolls that makes 1.5€/roll. I'm ok with it, but I'm sure I could squeeze in a couple more rolls if I really wanted.
I forgot to say that I mainly use 100/160 iso film, if you use a lot of 400/800/1600 you might get less good rolls out of the kit

 

[MattKing]

Low temperature C41 gives unsatisfactory results. Colour crossovers are inevitable, and if you are optically printing, they are terrible to deal with.
Even digital processing is difficult with crossovered negatives.

 

[canvassy]

I use the Tetenal press kits. You definitely get more rolls out of it than the box claims. I keep mine mixed up for about 10 months and usually put 40-45 rolls through it. I've seen people on APUG use their kit for a year and 50+ rolls, but I don't push my luck that much. The kits do keep for quite a long time though!

 

[TattyJJ]

That's good to know.
I have a 2.5L kit making it way to me. I have a JOBO CPE2 and can do 2 35mm films at once.
I was thinking about waiting till I have a load of film saved up and doing it all at once, but seems they keep pretty well so not sure it's worth it.

So, pre-soak and a stop bath will help drag it out, I'm guessing just a normal B&W acetic acid is fine?
I'm planning to use RO water to mix the chemicals as the tap water round my way is really hard, might even boil it as well to get the oxygen out.

Anything else might extend it's life a little?

 

[Berri]

That's good to know.
I have a 2.5L kit making it way to me. I have a JOBO CPE2 and can do 2 35mm films at once.
I was thinking about waiting till I have a load of film saved up and doing it all at once, but seems they keep pretty well so not sure it's worth it.

So, pre-soak and a stop bath will help drag it out, I'm guessing just a normal B&W acetic acid is fine?
I'm planning to use RO water to mix the chemicals as the tap water round my way is really hard, might even boil it as well to get the oxygen out.

Anything else might extend it's life a little?

I asked few days ago about acetic acid and it is ok, experts say not to use citric acid. You can also use diluted white vinager. Boiling water prior to mixing c41 will help to elimintate oxigen trapped inside the water, but it will inevitably come back after the first time you put your chemicals through the processor, so I don't think it is really worth the hussle. good idea to use distilled water, this will help to have clean negatives. I strongly raccomand using inert gas to protect your chemicals it works really well.
I believe, but I may be wrong, that rotary processor will oxigenate your chemicals a bit more than a normal tank, but I can't say if this will influence the life span of your chemicals.
keeping your chemicals in a fridge (or even freezer) is proven to increase the shelf life. No need to say not to put your chemicals in the same freidge you store your food, drinks or anything else!

 

[Berri]

Also remember that you will lose some volume each time you put a roll through the process, check if the amount you have left is enough to cover the whole film, or you will end up with uneven development, streaks and other issues. Pre-soaking will help maintaining the correct volume, but will dilute your chemicals a little bit every time, making necessary to increase the developing time accordingly. This is in theory, in practice I never adjust the dev. time and the results are satisfactory to me, I am not too critical about tiny density variations.

 

[TattyJJ]

All good stuff, thanks!

You say put the chemicals in the fridge or freezer.
My understanding was this is ok for the concentrate, but not a mixed working solution?

I use air duster for removing the oxygen of my B&W chemical bottles.
If you look up what they are made of it's exactly the same as the Tetenal stuff, but VASTLY cheaper!

 

[sfaber17]

So, if I get a a 2523 tank, I can do 2x rolls of 120 or 35 at a time, using 270mm of solution.

If you get a 1520 tank you can do the same in 240ml, so you get 4 runs per liter before re-use.

 

[Berri]

All good stuff, thanks!

You say put the chemicals in the fridge or freezer.
My understanding was this is ok for the concentrate, but not a mixed working solution?

I use air duster for removing the oxygen of my B&W chemical bottles.
If you look up what they are made of it's exactly the same as the Tetenal stuff, but VASTLY cheaper!

yes the concentrate. I use the air duster too, very cheap

 

[Wallendo]

I will be doing my first batch of C-41 in the next few weeks, and have found much of the documentation with the kits to be sparse and vague.
This FreeStyle listing is confusing, for example:
http://www.freestylephoto.biz/800341-CineStill-Liquid-Developing-Kit-for-C-41-Color-Film-1-Quart
Apparently one quart will develop 24 rolls of film (up to 10 at one time) ... and with reuse can develop up to 8 rolls of film. ???
My assumption is that 8 rolls is the real limit, but if you are shooting Cinestill film you won't notice any additional color shift until you've processed 24 rolls.

 

[rpavich]

Here are the capacities for Jobo tanks.