Delta 100 turned out to want a 35-percent decrease in development time to match curves for continuous agitation and intermittent agitation in D-76H 1:1 and 1:3...and a couple of oddities appeared.(posted 8448 days ago)When using intermittent agitation, the speed (defined as .10 DU above fb&f for Zone I) for D-76H 1:1 and 1:3 was EI 160, although I shot it at EI 100.
With continuous agitation, it dropped to EI 100 in D-76H 1:1 and EI 80 in 1:3. That's 2/3 stop slower for 1:1 and a full stop slower for 1:3! Also, at the 1:3 dilution a mild shoulder appears beginning at Zone X.
The same amount of stock was used for the 1:3 dilution for both the intermittent and continuous-agitation tests; no speed loss or change in curve shape was found with HP5+ in the same dilutions.
So...for Delta 100 in D-76H with continuous agitation it appears that the 1:1 dilution is the sweet spot, with the 1:3 dilution reserved for those times when I have to deal with excessive sky brightness etc.