Shortly after I started B&W developing way back around 1962 there was a film developer on the market called Ilford Hyfin. It was a powder developer which gave absolutely exquisite negatives, that were so sharp and fully toned they were far better than Agfa Rodinal. It was not a cheap product for what you got. 4 packets of powder, each packet made 500cc of working solution for only 2 of the Ilford films Pan F and FP3 (at the time no FP4). There were instructions that it was a 'use once and discard' developer. The keeping properties were minimal, even after processing one film, the colour of the developer had turned a distinctive yellow!l So I used to split a packet into 2 halves and make one half up to 250cc. The development time was I remember 18 minutes @ 68f. No variations were ever given. Shortly after wards I left home to join the Military and the next time I went to buy some it had been discontinued. I have since been in touch with Ilford and asked if they could release the formula so I could have some made up but they flatly refused, claiming it was commercially sensitive. They also declined to say if it would ever again become available to the general public. Has anyone else used this product and what did they think of it?