Ed, The following is from the Photo Lab Index dated 1980. HP5 -- gives brilliant, full scale negatives with remarkable detail in both highlights and shadow areas.(posted 8707 days ago)HP5 in Rodinal 1+75 -- ISO 200 (20)C 16 min (24)C 10 1/4 min
The development times are given for negatives printed in condenser enlargers with normal average scene brightness on grades 2 and 3 paper. The data assumes processing in a spiral tank with agitation for the first 10 seconds of development and then for 10 seconds every minute for the remainder of the development time. For continuous agitation reduce time by 25 to 40 percent.
The FP-4 chart mentions contrast development to a G of 0.55. I assume 0.55 also applies to HP5 data.
I looked up Agfa and Rodinal and came up with info for Plus X, a similar emulsion to Verichrome.
Plus X in Rodinal 1:100 ISO 125 (20)C 11 min Plus X in Rodianl 1:75 ISO 160 (20)C 12 min
Directions: Agitate continuously for the first minute, After the first minute, every thirty seconds give nild agitation for about five seconds, and continue this method until the desired development time as been achieved. For 72 degress decrease development time by 20%. Sorry, no contrast reference point was given but should be the same as current Rodinal directions.