Hi - I have a few Rollei Retro 400S film (120) around that I'd like to use soon, but what I shoot is a combination of landscape with some day-long exposures, for which I need to account for reciprocity failure. I haven't been able to find information on this subject for this film. Is there anyone out there familiar with the correction necessary for reciprocity failure ? Or any documentation to support it?

Thanks much.