Ilford DD-X reuse

[briandaly]

I have a batch of 4 35mm films I need to develop and wondered if it is wise to re-use the developer.
I'm using DD-X (1:4 dilution) in a daylight tank.
I've read that I should increase the development time by 10% for each film.
Anyone have any opinions or any experience of this?
How many films is it reasonable to develop before dumping the developer?

Thanks,
Brian

 

[MartinP]

The recommended re-use of DD-X is covered in the instructions on the container. The times and so on are based on a re-use from a one litre of mixed concentrate.

With the usual dilution of 1:4, you will use (4x60)=240ml of concentrate. Making up a litre of the stock solution will use 200ml of concentrate - but that litre can (according to Ilford) process a maximum of ten rolls of 36exp or of 120. The drawbacks are that the development times get much longer and rather more imprecise, plus the litre of DD-X stock "should" be used within 24 hours, plus push-processing is not recommended with this method due to the extra by-products of development (or some phrase like that, from memory).

It can make sense to try the litre of stock-solution idea if you have, for example a double reel tank and six rolls to develop. I have done this with no problem, but for four rolls there is little benefit.

Have you also looked at making up a litre of Microphen ? That will last longer as a stock-solution and has similar effects to DD-X.

 

[briandaly]

Thanks Martin.
I have an open bottle of DD-X I want to finish first.
Then I have a few packs of each of XTOL and D-76 that I want to use.
I've found Ilford's recommendations here http://www.ilfordphoto.com/Webfiles/20073211236917.pdf, but wondered how well it worked in practice.

 

[rich815]

I tried it and something funky happened. Firstly the "used" developer was sort of grey and a bit cloudy. And the second set of negs came out to my eye more grainy, and they were the same emulsion as the first set, shot in the same location and same camera, so the only really variable was the use of the used developer (and any subtle difference in my temps and agitation, that I tried to keep minimal). I would not do it for anything important. I will not be trying to do it again myself.

 

[MartinP]

A good point from rich, although his example sounds worse than normal - it is a good idea to filter the dev when you are reusing it (whatever sort of dev it is), as there is always the possibility of carrying tiny bits of something-or-other which would usually be thrown away if it was used once-only. A funnel with a twist of cotton-wool stuffed down it works fine - no need to buy lab-grade paper filters.

The Ilford quoted times go up by 10% per film-batch. This sounds simple and clear, but I have the impression that doing two lots of four rolls, or five lots of two rolls, or ten separate rolls (even despite the different volumes of developer obviously used in each scenario) will all result in slightly different chemical activities.

It does seem to work, but I'm sure someone armed with a densitometer and a testing-fetish could come up with some changes in performance. That said, my negs were still printable (I'd better say 'as printable as usual') with no discernible unwanted effects, just as suggested by Ilford.

Please let us know how it went as everyones circumstances are different and we can learn for the future.

 

[Silva Lining]

I use DD-X to develop 4 or 5 films from one batch of 1:4 solution in general adding 30 seconds on to the development time for each film. I've tried this with fuji Acros, Ilford Delta 100, 400 and PanF always with acceptable results. (In fact I can't remember the last time I just used the solution once !)