From 1965 to 1967 Coplans was director of the Art Gallery of the University of California at Irvine. As senior curator at the Pasadena Art Museum (1967 – 1970), Coplans was among the earliest champions of Pop Art and a vociferously sympathetic critic of the work of Roy Lichtenstein and especially Andy Warhol. Coplans began a series of exhibitions in a small gallery in the old Pasadena Art Museum which included West Coast artists Dewain Valentine, Doug Wheeler, James Turrell, Robert Irwin, Wayne Thiebaud, and Judy Chicago. In many of these cases, such as with Lichtenstein, it was their crucial first exhibition. Many of the catalogue essays that accompanied these exhibitions were also published in "ArtForum," bringing critical attention for these West Coast artists to a New York audience.