(1) I rate both HP5+ and Tri-X at EI 200 developed in my standard soup (HC-110 diluted 1:43). That's what gives me 0.1 above b+f at zone 1. With Microphen I can push the EI to around 400.(posted 8173 days ago)(2)My densitometry readings are based on two sources. First a Minolta Autometer IIIF. You can measure changes in transmission to 1/10 stop, then the change in OD is log(2^(change in stops)). Second I use a Perkin-Elmer Lambda 9000 UV/VIS/NIR spectrophotometer calibrated to NIST standards and I average density over the 450-600nm range. Note that I use the Minolta at home and the Perkin-Elmer at work! The two methods give suprisingly close results.