Metol storage, should I...

Ian Grant said:

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I don't use it [METOL] much because I prefer Phenidone as it's better (as in gives warmer tones) in Warm tone developers and I now only use Pyrocat HD as a film developer (all formats 35mm upwards).


Ian

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Ian,
Do you have a replacement value for Phenidone to Metol in a given formula, such as 1 to 1 or something like that?

Bruce Osgood said:

Do you have a replacement value for Phenidone to Metol in a given formula, such as 1 to 1 or something like that?

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Commonly reported conversion ratios are around 0.1g Phenidone for 1g Metol, but you won't get exactly the same developer. Also note, that Phenidone hydrolyzes in caustic environment, which means your Phenidone based developer won't have good keeping properties. Most commercial developers today use the more stable Dimezone-S, a substituted form of Phenidone, and you need about 0.15-0.2g Dimezone-S for 1g Metol. Sadly, Dimezone-S is hideously expensive compared to Phenidone.

Bruce Osgood said:

Ian,
Do you have a replacement value for Phenidone to Metol in a given formula, such as 1 to 1 or something like that?

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This Ian's site

http://www.lostlabours.co.uk/photography/formulae/developers/devPQ-ID11.htm

lots of non-metol formula's. if you browse

the sub is nearer 1:20 but a pub formula better.

Rudeofus and Xmas


Thank you for your insights. They help me in avoiding problems not yet realized.

And Ian, thank you for "lostlabors". A lot to enjoy here.

Bruce Osgood said:

Ian,
Do you have a replacement value for Phenidone to Metol in a given formula, such as 1 to 1 or something like that?

Click to expand...

There is no hard and fast rule for the amount of Phenione to replace Metol. It depends a lot on the developer itself. Whether it is a film developer (there are various types each with its own ratio) or a print developer. L F A Mason, Photographic Processing Chemistry gives ratios from 1:10 to 1:28 and even higher. The use of Phendone has been largely superseded by the two Dimezones which have better stability in solution.