Thursday I exposed & processed 3 sheets of Ilford Ortho Plus and measured the base-fog densities. The first sheet had a 10x12" Kodak 1A safelight directly overhead about 1 meter above the development tray. For the second sheet, I turned the safelight around so it bounced from the ceiling to illuminate, and for the third sheet, I turned that safelight off. For each of these, three other 1A safelights were illuminating the room via bounced light from distances of about 2, 3 & 4 meters. The FBF densities were 0.18, 0.08, and 0.06, respectively. The first sheet was given 5 minutes development and the other sheet received minutes development in HC110B. The first sheet was also 1 year older than the other two and since it was the last last sheet in a box handled by several others in a community darkroom it may have received some unknown cumulative exposure (but so could the others), this observation isn't OTBE. But, it seems to indicate that the film is responding to the red safelight especially when the illumination is direct rather than bounced. I suspect the effects would be more pronounced if a more active developer had been used.
Joe