1:1 Xtol and D96 in Jobo math problem

Radost · Mar 7, 2024

Hi,
I have been doing jobo stock D96 and Xtol and while I am happy with the results i miss my 1:1 sharpness and easy development at higher temperatures.
Shortening Jobo times and developing at 73F 74F makes the development times very short.
Kodak recommends minimum of 125ml stock per 135 film .
The math shows more liquid in a jobo tank than hand inversion recommendation.
1510 needs 170 for hand inversion. 70ml less than Kodak recommended. “jobo document below says that 100ml is enough.
Any body doing 1:1 in jobo?
Any advice?

Radost · Mar 7, 2024

I found this:

https://img1.wsimg.com/blobby/go/059fdc02-f8c5-4493-829d-bd516896d654/downloads/Kodak%20XTOL%20Developer.pdf?ver=1626884388425

Steven Lee · Mar 7, 2024

Ignore JOBO minimums and pour more to satisfy developer capacity requirements.

Radost · Mar 7, 2024

Steven Lee said:
Ignore JOBO minimums and pour more to satisfy developer capacity requirements.

So when the jobo is side ways some of the developer is outside the tank. I just don’t understand how filling up the tank all to the top works when the tank is rotating sideways…

Steven Lee · Mar 7, 2024

You don't necessarily have to fill it to the top, that's a bit extreme. My processor doesn't have a lift. I pour the required amount of developer, which is always more than JOBO minimums, close the lid, and put it into the machine.

But even if you don't close the lid, the maximum amount of liquid that a JOBO tank can take laying on the side without spilling is still higher than the stated minimums in JOBO manuals. You should have some room. Essentially, JOBO minimums are calculated to physically cover film with liquid. They do not take developer capacity into account. Therefore, the formula is max(jobo_minimum, developer_capacity_minimum).

Radost · Mar 7, 2024

Steven Lee said:
You don't necessarily have to fill it to the top, that's a bit extreme. My processor doesn't have a lift. I pour the required amount of developer, which is always more than JOBO minimums, close the lid, and put it into the machine.

But even if you don't close the lid, the maximum amount of liquid that a JOBO tank can take laying on the side without spilling is still higher than the stated minimums in JOBO manuals. You should have some room. Essentially, JOBO minimums are calculated to physically cover film with liquid. They do not take developer capacity into account. Therefore, the formula is max(jobo_minimum, developer_capacity_minimum).

I have a lift

pentaxuser · Mar 7, 2024

An interesting find in your #2, Radost My 1510 says 140 ml only is required and that certainly works for C41 using rotary. I have never used rotary processing for b&w film but from the document you linked to it sounds as if Kodak and Ilford films are OK at 1+1 with 100ml of Xtol stock so 200ml in the tank.I presume that 200ml does not spill out when using rotary processing?

It looks as if you have to use the bigger 1520 tank if you want to be sure of complete development with say 1+2 or with some developers 1+3 and wish to stick with the "recommended" stock levels

I'd try say 80ml stock at 1+1 and see what results you get. Some believe that with Perceptol for instance the minimum stock level is 250ml so that's a 1L tank with 1L of liquid rotating. Could that really be necessary? All I can say is that I wrote to Ilford and said that I had got good results with Perceptol 1+3 and 62 ml of stock but asked what their recommendation of stocl was and they replied that 70ml was safer. 70 ml is a long way short of 250 ml. OK that's Perceptol and not Xtol but maybe we need not be tied to this figure of 100ml for Xtol either It's all a question of what is acceptable to the user

After all if 100 ml is perfect then 99ml cannot be a disaster, can it? Can say 95ml be noticeably worse and so on down to that level where the stock level does not meet you requirements

It's try it and see or that how I would approach it

Here's a thought Wait a while until everyone has forgotten about this thread then place a picture in say the Gallery where you are looking for a critique of the picture and see if anyone mentions not achieving full Kodak CI or of the blacks not being black enough

pentaxuser

grahamp · Mar 7, 2024

Jobos have a maximum volume for rotary development - it varies a bit with the machine model, but the CPEs are limited to 600ml. That is for the motor and the largest tanks/drums it accepts.

You should be fine with any tank that takes two or more spirals of the format you are developing and putting in less than the maximum amount of film. If you want to work out the depth in a running tank, you need the circular segment formulas - Wikipedia has a nice page - and the displacement of your center column and reels for a given depth. But it really is not necessary.

Work out the volume of dilution you need for the film area being processed, and ensure it is between the maximum and minimum for the machine/tank/drum. Higher dilutions will probably need larger tanks.

You can always fill your tank, with reels, then place it level in the sink until it stops draining, and then measure the remainder. You want to be under that and inside the limits noted earlier.

You can stop and fix using the Jobo standard volumes, even if the developer volume was more.

MattKing · Mar 7, 2024

If you want to know what the permitted maximum liquid volume is for a developing tank:
1) put the reels and any core in a tank set up for rotary (not inversion) agitation;
2) fill the tank with water; and
3) tip it on it's side and roll it back and forth a bit until the water stops leaking out.
The amount that remains in the tank (minus a little bit for the amount displaced by film) is the absolute maximum - I would use a little bit less.
It is important to also remember that some machines have weight limitations for the tanks - large amounts of liquid weigh a fair bit.

Radost · Mar 9, 2024

MattKing said:
If you want to know what the permitted maximum liquid volume is for a developing tank:
1) put the reels and any core in a tank set up for rotary (not inversion) agitation;
2) fill the tank with water; and
3) tip it on it's side and roll it back and forth a bit until the water stops leaking out.
The amount that remains in the tank (minus a little bit for the amount displaced by film) is the absolute maximum - I would use a little bit less.
It is important to also remember that some machines have weight limitations for the tanks - large amounts of liquid weigh a fair bit.

Tried it. when I put 200 a little gets out…

mshchem · Mar 9, 2024

I use a next larger tank with diluted XTOL. Don't try and go below the 100 mL minimum. Kodak put in a tremendous amount of work putting together recommended times and dilutions for XTOL. The minimum amounts Jobo decided on work great with full strength one shot for color and black and white.

brbo · Mar 10, 2024

Radost said:
Tried it. then I put 200 a little gets out…

If you want to use Xtol 1:1 and religiously adhere to the "125ml minimum of stock solution per roll"... buy a 1520 tank.

Radost · Mar 10, 2024

brbo said:
If you want to use Xtol 1:1 and religiously adhere to the "125ml minimum of stock solution per roll"... buy a 1520 tank.

Kodak says 100ml
I have a 1520 tank. The problem is the jobo might keep rotating basically the same amount of chems and not refresh it. Maybe if i lift slightly every now and then. .

Bill Burk · Mar 10, 2024

Steven Lee said:
You don't necessarily have to fill it to the top, that's a bit extreme. My processor doesn't have a lift. I pour the required amount of developer, which is always more than JOBO minimums, close the lid, and put it into the machine.

But even if you don't close the lid, the maximum amount of liquid that a JOBO tank can take laying on the side without spilling is still higher than the stated minimums in JOBO manuals. You should have some room. Essentially, JOBO minimums are calculated to physically cover film with liquid. They do not take developer capacity into account. Therefore, the formula is max(jobo_minimum, developer_capacity_minimum).

For people with a lift how about factoring in max lift capacity (maybe a lower percentage like 80% of max to engineer a safety margin). And then devise recommended time extension that’s appropriate for the capacity deficit.

grahamp · Mar 10, 2024

The 1520 tank has a Jobo minimum of 240ml. With a single spiral set to 120, and a cog lid (for the Lift), the maximum solution with the tank horizontal is 300ml (I was curious, and measured it). Adding the 1530 extension puts the Jobo minimum at 240 + 330 = 570ml for up to 5 x 35mm or 3 x 120.

Jobos do disperse the solution. For one thing the space between the film is a spiral allowing flow, and the spiral itself has slots allowing lateral flow. The whole point of rotary processing is that the solution is not still relative to the film. In the half rotation the film is in air, the emulsion is saturated. In the other half of the cycle, the solution refreshes.

Jobos, and other rotary devices do work. Or I would not use one

Radost · Mar 10, 2024

grahamp said:
The 1520 tank has a Jobo minimum of 240ml. With a single spiral set to 120, and a cog lid (for the Lift), the maximum solution with the tank horizontal is 300ml (I was curious, and measured it). Adding the 1530 extension puts the Jobo minimum at 240 + 330 = 570ml for up to 5 x 35mm or 3 x 120.

Jobos do disperse the solution. For one thing the space between the film is a spiral allowing flow, and the spiral itself has slots allowing lateral flow. The whole point of rotary processing is that the solution is not still relative to the film. In the half rotation the film is in air, the emulsion is saturated. In the other half of the cycle, the solution refreshes.

Jobos, and other rotary devices do work. Or I would not use one

So the chems away from the reel get sucked in the the reel and it circles through? Considering I am putting only one reel inside a 1520 and it is at the bottom “end” of the reel, the chemicals keep cycling trough the reel?

mshchem · Mar 10, 2024

Radost said:
So the chems away from the reel get sucked in the the reel and it circles through? Considering I am putting only one reel inside a 1520 and it is at the bottom “end” of the reel, the chemicals keep cycling trough the reel?

Important to remember that the reel doesn't spin inside the tank like a Paterson. The Jobo tank, column and reel rotate as one unit, the solution is somewhat chaotic so every bit of the film experiences the same amount of chemistry.

The 100mL stock per 80 sq in is the stoichiometric requirement for complete development, per EKCo.

Radost · Mar 10, 2024

135 is 80sq inch?

mshchem · Mar 10, 2024

Radost said:
135 is 80sq inch?

135-36, 1 120, 1 8x10 is about the same. 80 sq in.

Sirius Glass · Mar 10, 2024

brbo said:
If you want to use Xtol 1:1 and religiously adhere to the "125ml minimum of stock solution per roll"... buy a 1520 tank.

I use 500ml replenished XTOL regardless of the number of rolls. The same for 4"x5" film in the 3010 Expert Drum.

Radost · Mar 10, 2024

mshchem said:
135-36, 1 120, 1 8x10 is about the same. 80 sq in.

Thanks . Should have googled it.
I will try D96 1:1. I feel like I can get more sharpness and less contrast the same way XTOL 1:1 does.
I am using 5222 and there is a grainess in white skin tones “similar to under exposed hp5” that I want to smooth out.

Radost · Mar 10, 2024

Also I know its counter productive for blown highlights to do it in Jobo but I am trying to not blow the highlights of 5222 and use a jobo

1:1 Xtol and D96 in Jobo math problem

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