Bob I think you're in the ballpark with EI 50 especially since neither of those developers are "speed" developers. Try adding 10g/L sodium sulfite to your Rodinal working solution; you may get back 1/3 to 2/3 stops or at least it'll be a solid EI 50, not iffy. Otherwise try D-76/ID-11; I use 18'/68F for D-76H 1:3 intermittent and 13'45"/68F D-76H 1:3 rotary.(posted 8162 days ago)I'd strongly suggest you try Delta 100 in D-76 1:1, 12'/68F intermittent or 7'50"/68F rotary, EI 100.