A Little Help with Signaling Devices

[Slappy]

Unfortunately I have no clever formulas, but I think the visible radius has a lot more to do with altitude and LOS than candle power at least at practical distances. I would suggest that if looking the right way on a clear night one would be able to spot just about any illumination round out to several km. The key would be whether the character was in fact looking in the right direction (matter of lookout SOP and luck) and whether the ILLUM was over the visible horizon (which could be dramatically shortened in woods or urban areas).
I would further suggest that detcetion would be automatic to at least 5x the effective illumination range as the light shed would be in obvious v. the background light at that range but not enough for effective illumination of targets.