In reply to LeeWood: Thanks for ideas. The P50 has a plethora of modes which may be useful with practice. Under the dial SCENE setting there are two which may be relevant: Night Portarit & Night Landcsape. The latter is supposed to fix the focus at infinity. After which there are several flash settings to experiment with.
Heh heh, I did explore a couple of small caves yesterday but after approach in heavy rain and a few squeeze passages I was well grimed up and had no wish to soil the camera. Oh, and the boy complained sorely because we got lost on the approach.