How to determine the correct amount of developer concentrate per roll for inversion and rotary processing

[logan2z]

I look forward to seeing its answer or your summary of it, should you want to share it

pentaxuser

I had a back and forth exchange with Ilford on the subject. I have to say, their customer service is excellent. Very quick responses and it was clear that their technical folks spent time investigating before responding.

Here is what they ultimately said (edited slightly to remove extraneous information and personal information):

You will be fine with 500mls at 1+4 for your two films as long as you have sufficient coverage...the one shot case is based on Patterson tanks of 300mls (16 films per bottle). In reality the max capacity is 50 films per bottle i.e. one film = 20mls concentrate, so this is the figure you can use.

...we are going to amend the tech sheet to explain this better. Hopefully this resolves your issue.

 

[pentaxuser]

Thanks, logan2z. So at 20ml per film we were both seriously over estimating the amount of DDX required. Assuming that I have interpreted correctly what Ilford has said to you. Here's what the current Ilford sheet says at the end.

"ILFOTEC DD-X is available in 1 litre bottles world-wide. Used at 1+4 for one shot processing it will develop 16x 135/36 films. If reuse techniques are used, it will develop up to 50x 135/36 or 120 films"

However earlier it says:1 Litre of ILFOTEC DD-X 1+4 can process up to 10 x 135/36 or 120 roll films provided that the developer is reused.

So currently Ilford's statements suggest that it can develop more films one shot (16) than it can by-re-usage(10) It then proceeds to completely contradict this figure of 10 by suggesting that it can develop 50 films by re-usage

Its statements are all over the place and, yes, it certainly needs to amend the tech sheet to clear this up.

As re-usage involves pouring back the used developer at 1+4 into the unused developer to get to 50 films but the percentage increases only cover 10 films, it would look as if the user has to make 1 litre of working strength DDX with 200 concentrate and 800 ml of water. Then use 200ml of the working strength for each film pouring it back into the 1L working strength each time until 10 films have been developed using the percentage increases it states. Dump the 1L of used working strength solution after 10 films and make up a fresh 1L of working strength solution and begin again for 10 films thereby getting to 50 films.

Thus 20ml of concentrate per film applies only for re-usage and is NOT a figure to be used one shot

If my logic is right then the best method for re-use is to divide the 1L of concentrate into 5 x 200ml bottles and use one at working strength at a time

50 films certainly reduces the cost of DDX per film considerably. My only concern is how long does the concentrate last in 200ml bottles and how long does 200ml once made into 1L of working strength last?

Anyway well done for getting what you did from Ilford and I look forward to seeing if its amendments to its tech sheet reflect what I think it is saying now

pentaxuser

 

[logan2z]

Thanks, logan2z. So at 20ml per film we were both seriously over estimating the amount of DDX required. Assuming that I have interpreted correctly what Ilford has said to you. Here's what the current Ilford sheet says at the end.

"ILFOTEC DD-X is available in 1 litre bottles world-wide. Used at 1+4 for one shot processing it will develop 16x 135/36 films. If reuse techniques are used, it will develop up to 50x 135/36 or 120 films"

However earlier it says:1 Litre of ILFOTEC DD-X 1+4 can process up to 10 x 135/36 or 120 roll films provided that the developer is reused.

So currently Ilford's statements suggest that it can develop more films one shot (16) than it can by-re-usage(10) It then proceeds to completely contradict this figure of 10 by suggesting that it can develop 50 films by re-usage

Its statements are all over the place and, yes, it certainly needs to amend the tech sheet to clear this up.

As re-usage involves pouring back the used developer at 1+4 into the unused developer to get to 50 films but the percentage increases only cover 10 films, it would look as if the user has to make 1 litre of working strength DDX with 200 concentrate and 800 ml of water. Then use 200ml of the working strength for each film pouring it back into the 1L working strength each time until 10 films have been developed using the percentage increases it states. Dump the 1L of used working strength solution after 10 films and make up a fresh 1L of working strength solution and begin again for 10 films thereby getting to 50 films.

Thus 20ml of concentrate per film applies only for re-usage and is NOT a figure to be used one shot

If my logic is right then the best method for re-use is to divide the 1L of concentrate into 5 x 200ml bottles and use one at working strength at a time

50 films certainly reduces the cost of DDX per film considerably. My only concern is how long does the concentrate last in 200ml bottles and how long does 200ml once made into 1L of working strength last?

Anyway well done for getting what you did from Ilford and I look forward to seeing if its amendments to its tech sheet reflect what I think it is saying now

pentaxuser

I omitted one statement from Ilford's response that might clarify the one-shot usage - or possibly confuse it further

In reality the max capacity is 50 films per bottle i.e. one film = 20mls concentrate, so this is the figure you can use.

You are not re-using so don’t need to bother about adding back to the stock / time adjustment etc..

I interpreted that to mean that the 20ml/roll figure was for one-shot processing, not re-use processing.

If that's the case, and you can also get 50 roll of film developed by re-using the working solution as you and Ilford have stated, then I'm not sure what is the point of re-use.

Hopefully their updates to their data sheet will clarify this once and for all.

 

[MattKing]

The difference between the two is due to the fact that the instructions put too much weight on the size of the tanks when talking about one shot developing.
If you are using the developer 1 + 4 in a 300 ml tank (one roll of 135) you need to use 60 ml of concentrate to make up that 300 ml of 1 +4. After using that 300 ml once, you discard it, including the 60 ml of concentrate in it. 16 x 60 ml ~= 1 litre.
If you are using the developer 1 + 4 in a 500 ml tank (one roll of 135) you need 100 ml of concentrate to make up that 500 ml. After using that 500 ml once, you discard it, including the 100 ml of concentrate in it. 10 x 100 ml = 1 litre.
In order to get the 50 rolls of development out of the 1 litre bottle, you will need to use the re-use the developer approach - the one that involves increasing the time by 10% as each film goes through the re-used developer.
Be sure to note the short 24 hour projected life of working strength (1 + 4) DDX. This means that if you mix up a litre of 1 + 4 intending to re-use it for 10 rolls, you will need to develop those 10 rolls within 24 hours of mixing.
I have to chuckle when I see the people at Harman referring to "Patterson" tanks, given that Harman distributes "Paterson" in the UK.

 

[logan2z]

The difference between the two is due to the fact that the instructions put too much weight on the size of the tanks when talking about one shot developing.
If you are using the developer 1 + 4 in a 300 ml tank (one roll of 135) you need to use 60 ml of concentrate to make up that 300 ml of 1 +4. After using that 300 ml once, you discard it, including the 60 ml of concentrate in it. 16 x 60 ml ~= 1 litre.
If you are using the developer 1 + 4 in a 500 ml tank (one roll of 135) you need 100 ml of concentrate to make up that 500 ml. After using that 500 ml once, you discard it, including the 100 ml of concentrate in it. 10 x 100 ml = 1 litre.
In order to get the 50 rolls of development out of the 1 litre bottle, you will need to use the re-use the developer approach - the one that involves increasing the time by 10% as each film goes through the re-used developer.
Be sure to note the short 24 hour projected life of working strength (1 + 4) DDX. This means that if you mix up a litre of 1 + 4 intending to re-use it for 10 rolls, you will need to develop those 10 rolls within 24 hours of mixing.
I have to chuckle when I see the people at Harman referring to "Patterson" tanks, given that Harman distributes "Paterson" in the UK.

Matt, I think your analysis is spot on for one-shot developing of a single roll of film in DD-X.

My question to Ilford was with respect to developing multiple rolls of film in a single tank, which is why I was trying to find out how much developer was truly needed to develop a single roll of film. Given their response, it seems like 20ml of developer concentrate - mixed 1:4 with water - is required to develop a single roll of film. So, if one had a 100ml tank, they could develop a single roll of film with 20ml of developer concentrate mixed with 80ml of water - which corresponds exactly to the first row of the table on page 2 of the DD-X data sheet:

Perhaps there was some logic to the inclusion of that tank size at the start of their table after all, and may have been a subtle clue to the minimum required developer amount.

Given all of this, it seems more than adequate to develop two rolls of film in a 500ml tank with DD-X mixed 1:4. That would leave 50ml of developer per roll. Rotary processing in a Jobo 1520 requires about 250ml of working solution, which would be comprised of 50ml of DD-X concentrate and 200 ml of water. For two rolls of film, that's 25ml of developer per roll which still exceeds the minimum required. So there's no issue developing two rolls of film in a Jobo 1520 with DD-X used one-shot for either inversion or rotary processing.

 

[MattKing]

So there's no issue developing two rolls of film in a Jobo 1520 with DD-X used one-shot for either inversion or rotary processing.

Correct, as long as you adjust the volume of working solution to suit the orientation of the tank - more in the vertical tank when using inversion agitation, and less in the horizontal tank when using continuous rotary agitation.

 

[pentaxuser]

Well it would seem, Matt, that we need to await Ilford's amendment to its tech sheet to see what it actually meant in its response to logan2z I hope we are all like Joe Friday of Dragnet and are just after the facts, ma'am

If logan2z's sentence in bold is actually what IlfordPhoto said to logan2z then it would appear unequivocal to me that 20ml of concentrate is all you need for each 135 or 120 film. Yes this makes a nonsense of 1+4 for a 135 film that requires 250ml minimum and turns the dilution into 1 + 12 for a Jobo tank. I usually quote a Jobo 1500 tank as 250ml but this is simple rounding up. It is in fact 240ml. As logan2z says it also make a nonsense of bothering with the extra effort to use a "re-use regime"

Assuming that Patterson is the actual spelling used by the Ilford spokesperson then this may simply indicate that it is just a spelling error. Happens a lot these days. I blame lack of education in English that afflicts all who are less than about 60 years old . How many spell the name of Floyd Patterson correctly or the name of the place in Noo Joisey which is Paterson

I admit it went over my head that the spelling was Patterson but I am unsure why this is germane to the discussion.

Was there any particular reason why you picked up on this at the end? Did it have any relevance to the substance of the IlfordPhoto reply to logan2z?

pentaxuser

 

[logan2z]

Now, if I just knew the minimum amount of HC-110 per roll. Some say 3ml, some say 6ml. I haven't seen anything in the Kodak literature that discusses it at all.

At high dilutions like H, I'd be at around 4ml per roll in a 500ml tank which seems like it's getting a little low, but maybe doable. Rotary processing seems like a no-go in a 500ml tank if using 250ml of working solution. It seems like a Jobo tank extension for the 1520 might be necessary for developing multiple rolls at very low dilutions.

 

[logan2z]

If logan2z's sentence in bold is actually what IlfordPhoto said to logan2z then it would appear unequivocal to me that 20ml of concentrate is all you need for each 135 or 120 film.

The two statements I included in bold were taken verbatim from Ilford's email response.

 

[MattKing]

Well it would seem, Matt, that we need to await Ilford's amendment to its tech sheet to see what it actually meant in its response to logan2z

Actually no - their response is consistent with the existing confusingly written tech sheet.
Ten rolls can be developed with 200 ml of concentrate diluted to a litre (1 + 4) if you either reuse it, or can figure out how to fully immerse a roll in 100 ml of solution.
Otherwise you are limited mostly by the minimum volume required by the reels and tank, where one shot works great, but doesn't make the most economical use of the concentrate.

 

[MattKing]

Now, if I just knew the minimum amount of HC-110 per roll. Some say 3ml, some say 6ml. I haven't seen anything in the Kodak literature that discusses it at all.

The logical inference to be made from the datasheet capacity information and information concerning use while replenishing is 6 ml. That includes the safety factor that a manufacturer oriented towards serving the commercial lab market (which HC-110 was originally designed for) will build into any capacity recommendation. The inclusion of the safety factor means you can often get away with less, but I never took the risk of using less than 5 ml per roll, and only with normal films, not films filled with lots of high key images.
Jason Brunner's 1 + 49 dilution is particularly practical - I could do 4 120 reels in a 1 litre tank, when I was willing to take the 5 ml risk.
Here is a link to a Photrio resouce with the 1 + 49 information:
https://www.photrio.com/forum/resources/hc110-made-simple.220/

 

[logan2z]

The logical inference to be made from the datasheet capacity information and information concerning use while replenishing is 6 ml. That includes the safety factor that a manufacturer oriented towards serving the commercial lab market (which HC-110 was originally designed for) will build into any capacity recommendation. The inclusion of the safety factor means you can often get away with less, but I never took the risk of using less than 5 ml per roll, and only with normal films, not films filled with lots of high key images.
Jason Brunner's 1 + 49 dilution is particularly practical - I could do 4 120 reels in a 1 litre tank, when I was willing to take the 5 ml risk.
Here is a link to a Photrio resouce with the 1 + 49 information:
https://www.photrio.com/forum/resources/hc110-made-simple.220/

Thanks, I'm just thinking ahead. Given the trouble I've had with streaking, I'm not ready to rock the boat at this point. If I get a string of good rolls developed one-at-a-time using HC-110 Dilution H then I may start to experiment. But not until then.

 

[pentaxuser]

logan2z, having looked at the full Ilford statement it does appear to confuse matters further rather than clarify it

"In reality the max capacity is 50 films per bottle i.e. one film = 20mls concentrate, so this is the figure you can use.

You are not re-using so don’t need to bother about adding back to the stock / time adjustment etc.."

I wonder if the llford responder realises that its statement may not say what it was trying to say

I agree with Matt sentiments or what I think were his sentiments that the 20ml as the minimum for one shot use, given we are talking about 135 and 120 films, is a figure that is so far from the 1+4 standard dilution and 240 mls minimum liquid that it is nothing less than astounding and as you say if it is correct then whoopee we can ignore the faff of re-use as it allows us to do the same 50 films as the re-usage method

What may be the case, based on the 20/80 figure that Ilford quotes, is that you might be able to make a container of some kind that such as a narrow trough that you could see-saw the film through but even then if,say 60ml of concentrate is require for a 135 film of 36 frames then this 20/80 is only going to develop properly one third of a film or about 12 frames. So all the faff of the right container, see-sawing etc for the sake of a short 12 frame film. Makes you wonder if there ever was a point in setting out its list of dilutions when as far as I can see most of them have no practical value

We are now getting close to the point where the maths leads us towards absurdity in terms of practicality of method

I await Ilford's changes but this may not be quick. I imagine an alteration to the tech sheets is relatively simple but if a similar sheet is included in each container of DDX that may not be so quick or easy

pentaxuser

 

[MattKing]

The OP is concerned about whether the quantity of diluted developer he/she wants to use is enough, given the dilution he/she intends to use is for the number of rolls he/she wants to develop in the tank size he/she has available.
Harman got back to him and clarified that as long as he/she has at least 20 ml of concentrate in the tank for each roll he is developing, he is fine.
The list of dilutions doesn't have any relevance to the capacity question, it is just an aid to calculate the necessary mix to fill the tank.
The tank and reel size and the type of agitation controls the volume constraints, and only indirectly affects the capacity question. It is important not to confuse the two.
No one is suggesting you use 100 ml of 1 + 4 DDX to develop your film. Harman is saying that you need at least 100 ml of 1 + 4 DDX to develop your film, but the actual amount used over that figure is based on the reel and tank and agitation regime.

 

[pentaxuser]

The OP is concerned about whether the quantity of diluted developer he/she wants to use is enough, given the dilution he/she intends to use is for the number of rolls he/she wants to develop in the tank size he/she has available.
Harman got back to him and clarified that as long as he/she has at least 20 ml of concentrate in the tank for each roll he is developing, he is fine.
.
No one is suggesting you use 100 ml of 1 + 4 DDX to develop your film. Harman is saying that you need at least 100 ml of 1 + 4 DDX to develop your film,

I'm even more confused that ever, Matt. So do you agree that Harman is right that with at least 2Oml of concentrate in the tank for each roll he is fine or are you simply saying that this is what Harman says but it's only right in the re-use scenario where you can develop 50 films with 1L of concentrate? In the re-use scenario mathematically it is 20ml of concentrate as 50 films divided into 1L is 20ml per film. but in this case the statement that he is fine with 20ml of concentrate needs quite a lot of qualification, surely?

If Harman is right and 20ml concentrate is OK for each 135 film then as it needs 240ml of liquid in the tank all anyone has to do is ignore the ratio of 1+4 and use 1 +11 or in a rotary process use 1 +7 = 140ml ?

pentaxuser

 

[MattKing]

One last try.
Capacity is different than coverage, which is also different than activity.
There is enough developing "oomph" in 20 ml of DDX concentrate to develop a roll of film without concerns about it prematurely exhausting.
But, capacity and exhaustion aren't the only things we care about. We also care about activity of working strength developer, and ph, and how much preservative is present and a bunch of other things. In most cases, 1 + 4 working strength works really differently than 1 + 11, because of all sorts of factors, including relative sulfite levels and a bunch of others.
The water in developer is a chemical too, and its ratio to the other chemicals matters.
In some cases, 1 + 4 may work well, while 1 + 11 may not work effectively at all.
You have to look at several things in order to develop the film.
1) you need enough liquid to cover the film and reels effectively - rotary agitation adds to your options there;
2) you need a developer dilution that will perform in the way that you want it to; and
3) after assuring yourself of the first two factors, you need to check that there is enough developing capacity in the working solution volume you are working with to avoid developer exhaustion.
The result of all these factors is that your reels and tanks and agitation schemes and dilution choices may force you to use more concentrate than the absolutely most economical minimum. That's life, and only some sort of radical re-design of the tanks and reels will change that.

 

[MattKing]

By the way, the multiple possible dilution options feature is probably the biggest single strength of HC-110. There just aren't a lot of developers that are capable of giving relatively similar results over such a wide range of dilutions. That is probably the reason HC-110 was as successful as it was in its target market - commercial labs.

 

[projectbluebird]

Harman got back to him and clarified that as long as he/she has at least 20 ml of concentrate in the tank for each roll he is developing, he is fine.

I would just like to say, thank you Matt (or Logan2z, for kicking off this thread.) I have been looking for this information (and not finding it) since I started using DDX a few months ago.

From this thread, minimum concentrate quantity is obviously less of a concern for manual inversion - but I have been looking into (manual) rotary processing, where minimum quantity is much more important. My motivation is less about economics (though that is a bonus) and more of a practical concern. I have (successfully!) used a 8 reel tank to process films with manual inversion - but the novelty of slinging around 2 liters of chemistry quickly wears off.