@Rudeofus: My formula requires that 90 g/L of sodium sulfite be mixed in separately from the concentrate. That makes it a little more hassle than HC-110, but it also means it gains the buffering and other benefits from the sulfite.
Originally Posted by Gerald C Koch
@BetterSense: My motive for creating this concentrate is to have something that will last for a few years. After mixing, XTOL lasts 6 months according to Kodak, and I can't use 5 litres in that time. So this concentrate is intended for people who shoot 2 rolls per month or less as a hobby. Those who shoot 3 rolls per month or more will be able to use all 5 litres of XTOL (undiluted) in 6 months. But for low volume shooters, the extra few minutes it takes to measure two things (sulfite and concentrate) is not a problem.
@PE: Thanks for the encouragement, and the note about alcohol. From prior tests with similar formulas, I believe sharpness will equal XTOL. But I'll certainly run sharpness tests with the actual concentrate. For now, grain is the main thing I'm watching, while keeping development-times identical to XTOL.
@Gerald: Do you know if the formula from that article matches the patent? I have the patent, but haven't been able to locate that article. If you have access to that article, can you post the formula?