A light flash given to the eye of Calliphora leads to a movement of the legs (light induced leg reflex) which most likely normally initiates flight of the animal. This reflex has a short latency (12 to 30 ms, depending upon light intensity) and is quite reproducible without habituation. The spectral sensitivity of the reflex shows that receptors R1-6 most likely govern the input to the reflex in dark adaptation, a contribution of receptors R7 can be demonstrated with selective chromatic adaptation.