Berke, now using his own name for screen credits, was equally capable in making comedies, mysteries, action adventures, and westerns.

In 1942, he joined Columbia, initially directing that studio's westerns with Charles Starrett and Russell Hayden, and then branching into more mainstream fare.

In 1944, he moved to RKO Radio Pictures, handling a variety of movies, including detective fiction (Dick Tracy, The Falcon), musical comedies, and Zane Grey westerns.

Without bothering with editing or any postproduction chores and with short shooting schedules, he was able to squeeze in eight or ten pictures a year.

"[2] According to Fleischer, Berke eventually pestered RKO executives enough to be assigned an A picture with a long shooting schedule and stars, and he still shot it in twelve days.