Experimenting with shooting HP5 at ISO 100 ... Helpful when all you have in stock is HP5 and you want to shoot in daylight with a shutter limited to 1/500 sec: it gives you some aperture control so you can choose different DoF settings.
Saturday Morning by the Cafe - San Jose 2021
Kodak Retina IIIc
Ilford HP5 @ ISO 100
Two frame stitch
Cypress - Santa Clara 2021
Kodak Retina IIIc
Ilford HP5 @ ISO 100
Essentially, to get the slower speed with HP5, I dilute HC-110 concentrate to 1+61 and process otherwise my normal way. I usually use 1+49 for ISO 320-400.
Enjoy! G