Involved in the biosynthesis of carotenoids spheroidene and spirilloxanthin. Catalyzes the hydration of neurosporene to the corresponding hydroxylated carotenoids 1-HO-neurosporene and that of lycopene to 1-HO-lycopene. It exhibits negligible activity in converting HO-neurosporene, HO-lycopene, or any other derivative such as spheroidene, 1-HO-3,4-didehydrolycopene. rhodopin = all-trans-lycopene + H2O 1,1'-dihydroxy-1,1',2,2'-tetrahydrolycopene = H2O + rhodopin Carotenoid biosynthesis; spheroidene biosynthesis. Belongs to the CrtC hydratase family.