Soooo.... new bullet to bite: Jobo CPE2+ and XTOL-R

JWMster · Jan 11, 2018

So with an eye to developing color C41, I decided to stretch for a Jobo CPE2+ to give myself the best chance at getting it right: holding temps even, rotating at the right speed, etc. Someone will tell me this isn't necessary, and maybe that's right, but this tilts the odds in my favor at least. So I'm going there.

But this brings up the question of XTOL-R and modifies it since the CPE2+ limits chem to 600ML. Omer tells me you can still do up to 6 rolls of 120 with this amount of chem at 75rpm in my existing Jobo 2500 series drum and 3 reels. Whether or not I'd want to is a different story. But if you did this and the hang with the 70ML per roll as the refresh rate on replenishing XTOL-R, I'd come up with adding 420ML to fresh to the mix. Suddenly, all the math changes and it looks like I'm ending up with my fresh portion of the solution rising rather than falling. I'm curious what folks are doing? Love to hear from you even if it's just to point me to the right link where this has all been discussed for JOBO CPE2+ before. (I didin't really find that so far, and Omer at CatLabs uses D76 and doesn't replenish...so there's that). Thanks!

Sirius Glass · Jan 11, 2018

You are on the right track. Use 'P' for tanks [35mm and 120] and '4' for drums [sheet film]. I do not use the water bath for black & white unless I need to lower the temperature. I prewet the film except for Tri-X in XTOL or replenished XTOL.

MattKing · Jan 11, 2018

JWMster said:
Omer tells me you can still do up to 6 rolls of 120 with this amount of chem at 75rpm in my existing Jobo 2500 series drum and 3 reels. Whether or not I'd want to is a different story. But if you did this and the hang with the 70ML per roll as the refresh rate on replenishing XTOL-R, I'd come up with adding 420ML to fresh to the mix. Suddenly, all the math changes and it looks like I'm ending up with my fresh portion of the solution rising rather than falling.

There are two reasons to replenish:
1) replace used developer capacity; and
2) remove (a portion of) after-development byproducts.
If you develop 6 rolls, you have 6 rolls worth of developer capacity to replace, and 6 rolls of developer byproduct to remove.
It is exactly the same as doing 2 rolls on three different occasions, one after another.
It has nothing to do with the ratio between "fresh" and "not fresh".

JWMster · Jan 11, 2018

Matt: Now I'm confused - or at least I've yet to understand your correction. If the formula in Kodak's paper is 70-ML replenished fluid per 300-MLused there's that. But if the assumption was something like 300-ML per film then replenishment could attach to # of films rather than # of ML fluid used originally. I guess the question is whether the dominant part here is the total fluid, or the number of films. In other words, is the dominant part of the equation 70ML per 300ML of fluid, or is it 70ML per film? There must be an adjustment somewhere that I don't have for the JOBO yet on # of ML's to use per film. I think JOBO also has a minimum quantity no matter how many films are in the tank.

Fact is that I must be missing the part of the JOBO spec for # ML's to use per film... as this may resolve my confusion. Am I making myself clear?

Sirius Glass · Jan 11, 2018

JWMster said:
Matt: Now I'm confused - or at least I've yet to understand your correction. If the formula in Kodak's paper is 70-ML replenished fluid per 300-MLused there's that. But if the assumption was something like 300-ML per film then replenishment could attach to # of films rather than # of ML fluid used originally. I guess the question is whether the dominant part here is the total fluid, or the number of films. In other words, is the dominant part of the equation 70ML per 300ML of fluid, or is it 70ML per film? There must be an adjustment somewhere that I don't have for the JOBO yet on # of ML's to use per film. I think JOBO also has a minimum quantity no matter how many films are in the tank.

Fact is that I must be missing the part of the JOBO spec for # ML's to use per film... as this may resolve my confusion. Am I making myself clear?

Do not worry about the 300ml assumption. I use one litter bottles and pour ~500ml into the Jobo processor. Then I add 70ml per roll [roll equivalent for sheet film] into the replenished XTOL bottle. When I empty the tank or drum into the replenished bottle, the bottle gets topped off and the excess overflows into the sink. Then I can put the top on the replenished XTOL bottle squeezing out the air. Note when I remove the hose the level drops a little so I have to squeeze out the air.

MattKing · Jan 11, 2018

First - ignore replenishment for a moment.
When you develop film in a tank of some sort, there are three things that go into calculating volumes of developer:
1) what maximum volume of developer can and should actually be held by the tank;
2) how much developer is needed to physically cover the film and physically ensure that development can be sufficiently even; and
3) how much developer is needed to ensure enough chemical activity for complete development, without developer exhaustion in the highlights.

With respect to the first criteria, things like JOBO processors have limits on how much they can hold, as well as how much weight of developer they can properly agitate. With some older models, you can fill them too far and damage them!

With respect to the second criteria, when it comes to rotary agitation, where the tank is on its side, you need a certain amount of liquid to be confident that the film remains sufficiently covered by developer for a sufficient percentage of time. That volume is affected by the size of the tank, how much film is in each reel, and the version of the reels you are using. JOBO's instructions gives you the recommended amounts - read them carefully.

The final/third criteria concerns how much chemical capacity a developer has - how much chemical "oomph" is there in a given quantity of developer. It is usually expressed in terms of how many rolls of film per a given volume of developer. It can also be expressed the other way - what minimum quantity of developer has enough "oomph" (chemical capacity) to develop a single roll of film. Different developers have different chemical capacity per volume - in some cases a lot of chemical capacity in a small quantity. Those sorts of developers are the ones that permit you to develop several films over several days in the same moderately small volume. Not surprisingly, dilution has an affect on capacity.

If you read the Kodak data on X-Tol it includes a recommendation that there should be at least 100 ml (not 300 ml) of stock developer available for each roll developed. That recommendation comes in the context of using X-Tol diluted and one-shot, but it gives you important information about what the minimum amount per roll needs to be in your 6 roll rotary agitation tank. If you don't have at least 600 ml in there, your development may be incomplete.

So pick a volume - most likely the JOBO recommended volume. As long as it is over 600 ml, X-Tol can develop the film.

Now look at the issue of replenishment. Six rolls will use up a substantial amount of chemical capacity of your two litre working solution, and will add a substantial amount of development byproducts to your two litre working solution. In order to keep the working solution in order, add 420 ml of fresh replenisher to what is left in the working solution bottle, fill the rest of the bottle with the recently used to develop six rolls developer, and discard whatever is left of that recently used developer - the amount discarded will be close to 420 ml.

Net result: chemical capacity maintained, and developer byproduct build-up controlled.

I'm not sure what your reference to 300 ml relates to.

Sirius Glass · Jan 11, 2018

MattKing said:
With respect to the first criteria, things like JOBO processors have limits on how much they can hold, as well as how much weight of developer they can properly agitate. With some older models, you can fill them too far and damage them!

With respect to the second criteria, when it comes to rotary agitation, where the tank is on its side, you need a certain amount of liquid to be confident that the film remains sufficiently covered by developer for a sufficient percentage of time. That volume is affected by the size of the tank, how much film is in each reel, and the version of the reels you are using. JOBO's instructions gives you the recommended amounts - read them carefully.

The final/third criteria concerns how much chemical capacity a developer has - how much chemical "oomph" is there in a given quantity of developer. It is usually expressed in terms of how many rolls of film per a given volume of developer. It can also be expressed the other way - what minimum quantity of developer has enough "oomph" (chemical capacity) to develop a single roll of film. Different developers have different chemical capacity per volume - in some cases a lot of chemical capacity in a small quantity. Those sorts of developers are the ones that permit you to develop several films over several days in the same moderately small volume. Not surprisingly, dilution has an affect on capacity.

If you read the Kodak data on X-Tol it includes a recommendation that there should be at least 100 ml (not 300 ml) of stock developer available for each roll developed. That recommendation comes in the context of using X-Tol diluted and one-shot, but it gives you important information about what the minimum amount per roll needs to be in your 6 roll rotary agitation tank. If you don't have at least 600 ml in there, your development may be incomplete.

So pick a volume - most likely the JOBO recommended volume. As long as it is over 600 ml, X-Tol can develop the film.

My 1540 tank and the 3010 Expert Drum do not need 600ml, in fact they take much less and the minimum is around half a liter. I use those a little more than the minimum amounts and I never had a problem with XTOL and replenished XTOL.

JWMster · Jan 11, 2018

Matt: Thanks. So just to assure that I'm tracking, I'm going to use a minimum of 100ML per film, and replenish with 70ML per film. No matter what... assuming that I am working within the minimum and maximum #'s the Jobo can handle. Note that myCPE2+ limit is 600ML according to Omer at CatLabs and according to the docs.
So no matter what else, looks like I can do up to 5 rolls of 35mm or 4 rolls of 120 and have the right volume for the machine - according to how I read it. So if I do 1 roll of 120 (or 35mm for that matter - given same footage), the volume is 170ML. My read is that then pour into the machine 170ML (minimum) of XTOL-R and when
this is done, I pour back into my 2 liter XTOL-R solution 70ML of NEW XTOL and 100ML of USED from the tank just developed. Similarly, if I do 2 rolls of 120 with 330ML, I pour in 330ML of XTOL-R and when I'm done, pour 140ML of NEW XTOL and 190ML of USED back into my 2 Liter XTOL-R container. Do I have it right, then?
or am I still missing it? THanks!

MattKing · Jan 11, 2018

JWMster said:
Matt: Thanks. So just to assure that I'm tracking, I'm going to use a minimum of 100ML per film, and replenish with 70ML per film. No matter what... assuming that I am working within the minimum and maximum #'s the Jobo can handle. Note that myCPE2+ limit is 600ML according to Omer at CatLabs and according to the docs.
So no matter what else, looks like I can do up to 5 rolls of 35mm or 4 rolls of 120 and have the right volume for the machine - according to how I read it. So if I do 1 roll of 120 (or 35mm for that matter - given same footage), the volume is 170ML. My read is that then pour into the machine 170ML (minimum) of XTOL-R and when
this is done, I pour back into my 2 liter XTOL-R solution 70ML of NEW XTOL and 100ML of USED from the tank just developed. Similarly, if I do 2 rolls of 120 with 330ML, I pour in 330ML of XTOL-R and when I'm done, pour 140ML of NEW XTOL and 190ML of USED back into my 2 Liter XTOL-R container. Do I have it right, then?
or am I still missing it? THanks!

You have it essentially right.
If the JOBO + tank will take 600 ml, you could use 600 ml for every processing run - 1 roll, 2 rolls, 4 rolls anything up to 6 rolls. It would all work the same, and it wouldn't cost you anything more. In my case, my Paterson tank takes one litre at a maximum, so that is the amount of developer I use each time I use the tank.
When you pour out the developer at the end of the development, pour it into an extra graduate, because the exact amount to discard will be determined by how much space is left in the working solution bottle after you have added the appropriate amount of replenisher. Don't measure it out ahead of time - pour from the extra graduate and fill to the fill line instead. Whatever is left, that is the amount to discard.

mshchem · Jan 12, 2018

Kodak recommends only ONE SHOT with C-41 developer and rotary. I have replenished but C-41 is so cheap I have gone back to one shot on developer only.

I used replenished XTOL for years in small and large tanks. When I use the Jobo I use and toss. If you use Jobo recommend minimums with XTOL you definitely need to use XTOL straight.

Sounds like I could go back to replenishment of XTOL with the Jobo based on your experience.

Any reason to worry about oxidation of the replenished XTOL in a Jobo?

Best Regards Mike

mshchem · Jan 12, 2018

MattKing said:
First - ignore replenishment for a moment.
When you develop film in a tank of some sort, there are three things that go into calculating volumes of developer:
1) what maximum volume of developer can and should actually be held by the tank;
2) how much developer is needed to physically cover the film and physically ensure that development can be sufficiently even; and
3) how much developer is needed to ensure enough chemical activity for complete development, without developer exhaustion in the highlights.

With respect to the first criteria, things like JOBO processors have limits on how much they can hold, as well as how much weight of developer they can properly agitate. With some older models, you can fill them too far and damage them!

With respect to the second criteria, when it comes to rotary agitation, where the tank is on its side, you need a certain amount of liquid to be confident that the film remains sufficiently covered by developer for a sufficient percentage of time. That volume is affected by the size of the tank, how much film is in each reel, and the version of the reels you are using. JOBO's instructions gives you the recommended amounts - read them carefully.

The final/third criteria concerns how much chemical capacity a developer has - how much chemical "oomph" is there in a given quantity of developer. It is usually expressed in terms of how many rolls of film per a given volume of developer. It can also be expressed the other way - what minimum quantity of developer has enough "oomph" (chemical capacity) to develop a single roll of film. Different developers have different chemical capacity per volume - in some cases a lot of chemical capacity in a small quantity. Those sorts of developers are the ones that permit you to develop several films over several days in the same moderately small volume. Not surprisingly, dilution has an affect on capacity.

If you read the Kodak data on X-Tol it includes a recommendation that there should be at least 100 ml (not 300 ml) of stock developer available for each roll developed. That recommendation comes in the context of using X-Tol diluted and one-shot, but it gives you important information about what the minimum amount per roll needs to be in your 6 roll rotary agitation tank. If you don't have at least 600 ml in there, your development may be incomplete.

So pick a volume - most likely the JOBO recommended volume. As long as it is over 600 ml, X-Tol can develop the film.

Now look at the issue of replenishment. Six rolls will use up a substantial amount of chemical capacity of your two litre working solution, and will add a substantial amount of development byproducts to your two litre working solution. In order to keep the working solution in order, add 420 ml of fresh replenisher to what is left in the working solution bottle, fill the rest of the bottle with the recently used to develop six rolls developer, and discard whatever is left of that recently used developer - the amount discarded will be close to 420 ml.

Net result: chemical capacity maintained, and developer byproduct build-up controlled.

I'm not sure what your reference to 300 ml relates to.

Well said Matt.
Best Regards Mike

MattKing · Jan 12, 2018

mshchem said:
Any reason to worry about oxidation of the replenished XTOL in a Jobo?

j109 gives comparative information for rotary processing - fresh full strength developer (one shot), fresh 1+1 diluted developer (one shot) and seasoned (replenished developer.
One table, three columns side by side.
As you are using fairly small quantities in a JOBO, you are discarding a fair bit of the potentially oxidized developer anyways when you replenish.

mshchem · Jan 12, 2018

MattKing said:
j109 gives comparative information for rotary processing - fresh full strength developer (one shot), fresh 1+1 diluted developer (one shot) and seasoned (replenished developer.
One table, three columns side by side.
As you are using fairly small quantities in a JOBO, you are discarding a fair bit of the potentially oxidized developer anyways when you replenish.

Good point volume for 1 36 exposure roll in a 1520 tank is 140 mL, so you toss half of it. Reminds me of Cibachrome. I used 50:50 fresh and used.

I'm going to go back to replenishment. Good explanation Matt
Thanks, Mike

JWMster · Jan 12, 2018

Thanks Matt, Mike, et al. Machine should get here early next week. With some set-up, maybe I'll be able to test out some of this next weekend. Meantime, ain't it sweet to have incentive to shoot some films just to have some raw material for testing? You bet!

Tim Stapp · Jan 15, 2018

Sirius Glass said:
You are on the right track. Use 'P' for tanks [35mm and 120] and '4' for drums [sheet film]. I do not use the water bath for black & white unless I need to lower the temperature. I prewet the film except for Tri-X in XTOL or replenished XTOL.

Sirius, he is using the CPE2+. Therefore, limited to one rotational speed only: "ON."

Sirius Glass · Jan 15, 2018

I missed that, but the information is there for anyone who is searching for information on Jobo processors and XTOL. Both parts took me a while to find.

Soooo.... new bullet to bite: Jobo CPE2+ and XTOL-R

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Soooo.... new bullet to bite: Jobo CPE2+ and XTOL-R

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