Prescysol and the Zone System

All this talk of Prescysol reminded me that Peter Hogan is scheduled to join the East Midlands Monochrome Group for a chat on Wednesday the 5th April. Visitors are most welcome at this, and any of our other meetings. Details at:

Dead Link Removed

So book your flight now folks.

Commercial over.

being that I live on chalk, the water here is very hard ... yet I use it to mix all my chemicals with very little problem ... it did mess up my dixactol when i tried that a few years back though, and like dave, only using distilled water for stock solutions.

Did I read somewhere that hard water is better for fixing than soft? Or am I hallucinating? :confused:
I’ve been Bromoiling again today, and it’s made my arm ache, a fact that has nothing to do with anything; so I won’t mention it. :rolleyes:

Dave Miller said:

Pentaxuser, Northamptonshire water hard? I thought it quite soft, but then I moved here from south of the Thames where they don’t have to put cement in the water to build houses. In the summer I collect water from my darkroom a/c and use that after filtering. Recently I have brought some by adding it to paper/chemical orders from Retrophotographic. I think I’ve said before that I only use distilled for mixing stock solutions, and the final film rinse, so a little goes a long way.

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Thanks Dave Stoo and Leon. As none of you uses water direct from the tap for developing, it looks as if I might just have to suck it and see, if I go for Prescysol. I have used only Rodinal and Ilford devs(ID11 and Perceptol) to date and have never had a problems with negs with ordinary tap water. I wonder what my chances are that Prescysol will be as equally unaffected as my current devs are by tap water? When I bought most of my kit secondhand there was a filter which can be attached to the tap. Never used it. It is called Flokleen( these marketing herberts can never spell). The filter inside the perspex cylinder looks like a silvered version of a car oil filter. The filter looks the kind that is replaceable.That could be my fallback if I need to use filtered water. I don't know who makes/made these or how you tell if the filter is still in good condition. It has no stains or other marks to suggest it was heavily used. Anyone own one or one that is similar?

Dave.Looks as if I need to try and make the Peter Hogan meeting if at all possible. I do know that hard water is good for your heart and bad for whisky. There's none in Scotland which is why it has about the worst record for heart attacks but the happiest victims

Cheers

Pentaxuser

Pentaxuser,

I use tap water through a Britta filter. Have also used distilled water and noticed no difference (with a range of developers). Our water in Hampshire is not that bad but limescale does build up in the kettle when unfiltered water is used.

Stoo, thanks for your note, I will continue to use alkali fix as I agree with Dave's arguments:
- if used only for film it is not that much more expensive and given all the money spent on equipment a few pence on fixer won't make much difference
- Peter has done much more testing than I ever will

It is however good to know that alternatives are available should they be needed.

Regards, Erwin

pentaxuser said:

Thanks Dave Stoo and Leon. As none of you uses water direct from the tap for developing, it looks as if I might just have to suck it and see, if I go for Prescysol.

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Sorry p'user ... i wasnt very clear. I only use distilled water to mix my chems into stock solutions. I always use water staight from the tap to mix to working strengths. No problems at all - and definitely no problems when I used Precyscol. But if you're concerned, I'm sure there'll be no harm in filtering

and dave, I've got some ralgex I could lend you ... but then again, suffering for art is no bad thing

Leon. Thanks for that clarification.

Pentaxuser

De-ionized water is available from your local Halfords (or similar) for a few quid per 5 litres if you find a problem with filtered.

Cheers, Bob.

Dave Miller said:

If you use a Paterson Orbital processer then you will only need to use 60ml per 4 sheets of film.

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Hi Dave, After a delay, I've just got my hands on an orbital processor with motorbase. By how much do you modify the dev time if using continuous agitation with your base? The Paterson Orbital needs a minimum of 450ml to cover 4 sheets of 5x4 when still so continuous agitation or larger quantities of chem must be needed.

To follow up Leon's suggestion for N+1 development, doubling the quantities of solution B in Prescysol seems to be about right (not a very scientific analysis!) for me.

Also, last weekend I developed some 35mm HP5 exposed nearly 9 years ago and the negs are beautiful using Prescysol - and they print like a dream.

Mark

As you have guessed Mark you do need continuous agitation, that’s why the motor base is so useful, if you are going to use the recommended 60ml of fluid. As for time I have always followed the chemical manufacturers’ recommendation for machine development, generally about 10 to 15% reduction in time, but experimentation is the name of the game. However for Prescysol I would stick with the 8½ minutes to start with since it does seem to be dilution rather than time dependent.

Dave Miller said:

However for Prescysol I would stick with the 8½ minutes to start with since it does seem to be dilution rather than time dependent.

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Thanks Dave, that's where I would have started but it's nice to have it confirmed.

Mark

Just out of interest I’ve dug out the edition of Darkroom User with Roger Hicks article in. Issue #31 – 1997/5 if anyone wants to look it up. Roger described the modifications he made to the Paterson Orbital unit by roughening the base, and said that he confirmed with Ilford that the recommended 55ml of developer was adequate for 4 sheets of 5x4 film. They confirmed that it was. Geoffrey Crawley said that discrepancies in developer activity in the range 18 to 24 C would be negligible. Roger Hicks applied what he called “Kentucky Windage” to ascertaining the development time and reduced it by 10% plus a bit because that seemed to be the thing to do.

Now, can someone explain the principle that says that when looking through a stack of magazines for an article, it will always be in the last one examined; unless you happen to look in that one first! :confused: