I use FX2 quite a bit, mostly with Pan F but also with APX100. It provides about a 2/3 true increase in film speed. I use it as a stand develop with a development time of 60 minutes at 68 degrees F and no agitation. I have also tried it with Tri-X a couple of times with uncertain results. It did not look that bad exposed at EI 640 but did not look quite right either.(posted 8204 days ago)