Quote:
Originally Posted by Rob Archer
The formula I use for microphen is the one from The Darkroom Cookbook (#21) which is described as 'microphen-type'. I use the times given for Ilford Microphen and find it works fine. My personal taste is for a slightly higher contrast negative so I usually develop for 10% above the published times. The formula:
Water 52°C. 750ml
Sodium Sulphite (anh)100g
Hydroquinone 5g
Borax 3g
Boric acid 3.5g
Potassium bromide 1g
Phenidone 0.2g
Cold water to 1litre
This is now my standard developer for faster films.
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That's the published formula for Autophen, Steve Anchell corrected it in the 3rd Edition of The DCB along with a large number of other errors.
In the 1950's Ilford Research release a number of article in the BJP relating to the evolution of Autophen and it's replenishment and naming the above formula as Autophen.
Shortly after they released Microphen, and published ID-68, stating this was an entirely new developer. By reducing the Sulphite to 80g per litre as well as using Phenidone Microphen/ID-68 gives a speed increase compared to ID-11(D76) and Autophen.
Microphen is closer to being a PQ version of Adox Borax MQ or Agfa 44 (Agfa Ansco 17) both ofnwhich give a slight 1/3 stop speed increase compared to ID-11, Microphen is more like 2/3 stop speed increase.
Ian