By the chromophore extraction-HPLC method, it has been shown that an isomeric mixture of pigments (9,11-dicis, 9-cis, and 9,13-dicis) was formed from interaction of 9-cis, 11-cis-retinal with bovine opsin. That from 7-cis,9-cis-retinal retained the original geometry and that from 7,13-dicis contained almost completely the isomerized 7-cis pigment. © 1990.