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