Tacita Dean The Green Ray Author:Tacita Dean, Tacita Dean The green ray is an optical phenomenon that occurs during the last moment of the sun's setting. Rarely seen from land, and then only when the horizon over the sea is 100% clear, it appears here, on a few pages of a flip-book which documents an entire sunset in Madagascar. The stills are taken from Tacita Dean's 2001 video Green Ray on Madagascar.