Kubrick was notorious for demanding multiple takes during filming to perfect his art, and his relentless approach was often extremely demanding for his actors. Jack Nicholson remarked that Kubrick would often demand up to fifty takes of a scene. Nicole Kidman explains that the large number of takes he often required stopped actors from consciously thinking about technique, thereby helping them enter a "deeper place". Kubrick's high take ratio was considered by some critics as "irrational"; he firmly believed that actors were at their best during the filming, as opposed to rehearsals, due to the sense of intense excitement that it generates. Kubrick explained: "Actors are essentially emotion-producing instruments, and some are always tuned and ready while others will reach a fantastic pitch on one take and never equal it again, no matter how hard they try" ...