Kodak C-41 Gallon Sized Color Developer Capacity

Dave;

Michael's question was, I believe, could you use less fresh developer with longer time to achieve good curve shape, grain, color etc. He was not asking about 'seasoned' developer if I understand him correctly.

Here is my answer. Seasoned developer gains in restrainer concentration and loses in developer and alkali concetration. The time compensation for one roll of 220 is about 5% which is just at the detectable level in sensitometry. I don't think that there will be much change, as the local concentrations of these chemicals will be much different due to micro effects and diffusion. However, with the right amount of developer solution present, those things should be in reasonable balance.

If you use too little solution and extend the time, I would imagine that the situation would be slightly different in that the total alkalinity would be different.

Here is a hypothetical example of a film that needs 1 liter per roll. If there is 5 g/l of CD4 in the developer and after 1 roll it is 5% used then you would have 4.75 g/l of developer. However, if you used only 1/2 liter, expecting to increase development time, you only have 2.5 g of developer present even though it is still at 5 g/l, so the mass effect is different in developer, buffer etc and might affect the process as it has to be spread out over the same area. You can extend this by imagining the continuing decrease of the amount of developer to the point where it will no longer wet the entire surface of the film. So exhaustion is not the same as dilution or decreasing the quantity below a critical level.

EK has defined this critical level as 1 pint or about 470 ml for one roll of 220 film.

As for bleach and fix, EK states in my literature and manuals that these solutions have about 2x the capacity or more and about 2x the keeping or more than the developer. In practice, I find this to be more like 4 - 6x in both capacity and keeping, but I do extend my bleach and fix times.

Ron Mowrey

Ron, I was thiking, instead of 470ml per roll one shot, to process

with 640ml (or up to 1 liter) per roll then reuse with exteded time

for the second roll. The result of the first roll would be perfect.

But I worry about the 2nd in grain and colors (not so much about density).

I can believe (with a little doubt due to experience) 470ml per roll

one shot. If 470ml is the critical point for one 220 roll then I should never try to develop two rolls at one run with the same amount

of developer. This is basically what my probelms were last year.

How about process only one 220 with 470ml then reuse for the 2nd

roll but with a liter of this used (once) developer with extended time? If it gives OK density will it result coarse grain and poor colors? I don't mean that I will do it rather I woder what would

the result look like.

Dan, color TV CRT fades from deteriating phosphorus materials behind

the screen. But it is color dyes or pigments behind a LCD screen.

It may take 100 years for pigments to fade. It may take 100 years for

dyes based on nano technology to fade too. The pixel sized filters

behind LCD screen are very pure and accurate in colors (RGB). If a LCD

display does not have pretty colors it is the CCFL light souce that

does not emit pure RGB mixture of light. CCFL light source is similar

to CRT tube in that the light comes from phosphorous materials.

Well, CCFL has a 500,000 hours MTBF life on average. If you leave it on it will

take 10 years to lose half its brightness. TV CRT tubes are much shorter around 1000 to 2000 hours only. Plasma display also has only

one to two thousand hours before losing half of its brightness.

Dave;

Sorry I was not clear then.

Taking the 5% change in process time as an estimate in the change in chemical balance if you will, then a 5% error in overall characteristics of the film, compensated for by development, will be barely noticeable. This is due to the fact that the effects in question are balancing each other and end up making little change overall when one does things properly.

Doing two rolls at the same time should have even less effect as the changes are not complete in the developer, but are taking place slowly and locally for all practical purposes in each individual roll of film.

Therefore, there should be no problem either way when you run up to 2 rolls of film in one pint either consecutively (I don't really recommend this due to the dilution effect of the prewet) or at the same time (this is what I do).

Ron Mowrey

Dave,

Repeat after me... Bigger drum, bigger drum, bigger drum.

You won't be able to cram a pint into a 1540 drum and have it slosh around enough to not worry about local exhaustion, which is what I'm thinking is the problem.

Here's a quickie test: Load four 135-36 C-41 rolls (320 square inches -- Same as two 220 rolls) into the smallest 15xx drum the 4 reels will fit in. Process, and look for "weird stuff" in the vicinity of the sprocket holes.

For what it will cost you for a few test rolls of 160 square inch 220 film, you can buy a 25xx drum & a couple 2502 reels... And put your 220 problems to bed once and for all.

Dan

Ron,

I am looking at Kodak publication Z-131, Table 3-3, where it says that one gallon of C-41 developer has a capacity of 5 or 4 roll films 220, depending on the film. That's not the 3 films per gallon that I implied above, but it is still quite a lot of chemistry per film, and I wonder why other manufacturers quote much higher capacity for their C-41 products.

Michael;

If you look at my scanned capacity information it shows 1 roll / pint or 8 / gal unadjusted and 24 / gallon with adjusted development times.

I get 2 rolls / pint undadjusted using Jobo recommendations which work just fine if you do both at the same time.

Kodak is being very conservative, I guess as they are changing the suggested capacity downwards. The data I posted were valid from 1977 - 1996 or thereabouts. Or perhaps someone made a typo in the new instructions as the old ones were good for about 20 years. I know that the developer has not changed in that time.

Ron Mowrey

Dan, I understand your point. I will be looking for 25xx drums and

reels. But Ron insisted that he could do 2 220rolls in one 15xx drum

with one pint (470ml) of developer. When I did that the result was

always poor. And Kodak Z-131 seems a confirmation of that. Now I am

willing to believe that it may be OK to process only one 220 roll

in a 15xx drum at a time with same 470ml of developer. My NPS roll

was not great still. I am skeptical about two 220 rolls with one

pint developer. Well, 25xx drum will allow me to pour in a lot more developer. What I really hoped is to do 2 rools per 15xx drum (470ml).

It seems impossible now.

I did go out today but the weather has changed enough to make me

turn back with no shots taken. I will have to wait for another week

as the forcast says it will rain tomorrow.

Dave;

If you do 1 roll in 1 pint and it is not good, then something BAD is going on there!

I guarantee it.

Ron Mowrey

Ron, it is the two rolls that I have doubt. But I will not rule it

out without further experiment. Thank you so much for all your input.

Dave;

The problem I have is that your original post here says that with even one roll, the negatives are thin. That is what makes me feel that something else is going wrong.

I was doing some thinking about your problem, and I wondered if you might have had some of the prewet left in the drum when the developer went in. That dilution would cause the problem you report.

Ron Mowrey

Ron, I have quite a bit of doubt in 2 220 rolls in one 1540 drum with

470 ml of developer. I am a little skeptical about 1 220 roll with

same everything of the rest. If I remember correctly results of my

1 roll runs were mixed. Some might have been good but some not.

The ATL-2300 has a problem based on my observation of the machine.

If I run a cleaning cycle by filling all chemcial supply bottles with

water and let the machine go through a flush cycle to clean all

bottles and hoses, at the end I will see some residue water in the hoses between the supply bottles and the pump. I estimate the amount of water in the hoses is around 10 cc.

I have not figured out how to get rid of the water from the hoses

yet. I did empty all supply bottles to make sure no water remained there before pouring in fresh chemicals. Maybe the residue water

in the hoses is ruining my processing?

I do not prewet my films. The tank was always dry to begin with.

In the 4 minute prewarm cycle I am sure no water got into the tank.

I have done a measure of processing temp. It was 100F right on.

The amount of efluent was around 450ml+/-.

BTW, the density of the resulted films seem dense enough. The grain

and color balance are the complaints I have. Most my Portra 160/400 NC/VC seem quite grainy, except the recent 400VC. I like 400VC now.

Managed to shoot half a roll of 400UC today in San Francisco's Golden

Gate Park. Once it is done I will try it alone in a 1540 with 470ml

again.

Dave;

Again, with weak development, grain and balance don't suffer. Speed and contrast go first. That is why this entire scenario is bothering me. Something is going on here.

BTW, a prewet is recommended by both Jobo and EK, as the preheat cycle does not heat up the inner portions of the drum evenly the way a water prewet does. Also, the prewet swells the film allowing smooth penetration of the developer solution. Could that be the problem? IDK, but I always prewet film and paper, even B&W in the Jobo.

Ron Mowrey

Dave;

One little thing that might influence your results. If your atl does not rinse out all bleach and fix properly after you're done with it, that might account for your problems with grain and colour. Just an idea as you say you have residual water in connecting hoses and that density does not suffer, but grain.

Never used kodak c41 myself, but have achieved exellent results with two 35mm rolls in 250 ml developer both from jobo and agfa which would correspond to one 220 roll in film area. This in a cpa with 1500 series drum.

This is why i suspect you might suffer some contamination. maybe there's some nooks and crannies in hose-joints that might hold solution. Good luck troubleshooting your atl!

Anders, That's a good point. I believe the cleaning cycles are factory programmed but I can always reprogram it if I need to. The residue

water was found in the hose between supply bottles and the pump. There is one hose for every supply bottle. So the residue water should have no chance to contaminate other hoses. But without dismantling the machine I can't tell exactly.

Able to process 2 35mm rolls (36 exposure) per 250ml is fantastic.

I am going to have to experiment with 35mm rolls to see if it will

work for my 2300. Thanks for your input.

Ron, the reason I do not prewet before the developer step is to

avoid further diluting the developer that is already low in volume.

I am going to have to try it next time. Thanks for the tip. I was

actually concerned about prewarm myself. It is true the prewarm

cycle is not likely to warm up the reels and films in the tank.

Thanks again for your invaluable help.

"BTW, a prewet is recommended by both Jobo and EK"

Ron, I looked up Kodak web pages but could not find the recommendation

of prewetting the film. I alos checked Jobo instruction manual it

actually recommends not to prewet but to prewarm the empty tank for

5 minutes. I remember reading some c-41 processing articles that

strongly opposed to prewetting of films. It will reduce developer

strength significantly as the film will have already absobed much

water in it. The developer comes in contact with the film later

will be diluted by the water already absorbed in the film.

I am afraid I do not agree to prewet the film.

Dave;

I have examined three sources by Jobo. I have not looked at any EK refereces yet.

In the Journal of Rotary Processing, one chapter refers to prewet for film and another refers to pre heat of film and pre wet of papers. This is followed in the other two books (the CPP and CPE manuals) by similarly ambiguous comments. So, it appears that you are right about Jobo.

However, I use a prewet for every process including B&W. I get results comparable to the local pro labs.

Sorry about the confusion. I'll look for my EK references tomorrow, but I would imagine that it only applies to paper. IDK.

Ron Mowrey

Dave,

If Ron says to prewet, then do it! :)

Dan, it probably won't go wrong. I will try it to see if it makes

things better.

Guys;

Thanks for the confidence, but I do it and it works for me. That does not mean that the procedure is recommended or right.

If you try it, I hope it works for you Dave.

Ron Mowrey

Ron, many years ago when I did simple stainless steel tank processing

I always prewetted my films for sometime. I don't think I had problems.

But then I saw the article that opposed it so I stopped doing it.

If it solves my problem it may be a good solution. I prewetted the film

at around 105 degree to make sure when the developer met the film

it wasn't cooled down below 100.