Gunzburg and his brother Julian thought they had a solution with their Natural Vision 3D film process. They shopped it around Hollywood. 20th Century Fox was focusing on the introduction of CinemaScope and had no interest in another new process. Both Columbia and Paramount passed it up. Only John Arnold, who headed the Metro-Goldwyn-Mayer camera department, was impressed enough to convince MGM to take an option on it, but they quickly let the option lapse. Milton Gunzburg turned his focus to independent producers and demonstrated Natural Vision to Arch Oboler, producer and writer of the popular Lights Out radio show. Oboler was impressed enough to option it for his next film project. Oboler said he had overheard Joseph Biroc and the camera crew talking about 3D while filming The Twonky and Oboler became interested. Production Oboler announced the project in March 1952. He said it would be called The Lions of Gulu and would include footage shot in Africa several years beforehand. Filming was to start in May. It was always going to be in Natural Vision. Howard Duff and Hope Miller were the first stars signed. Eventually Duff and Miller dropped out and were replaced by Robert Stack and Barbara Britton. The title of Oboler's film was changed to Bwana Devil in June 1952. (Oboler already announced he would make a second film in the format, Spear in the Sand with Lisa Howard.) The film was shot in the San Fernando Valley. The Paramount Ranch, now located in The Santa Monica Mountains National Recreation Area, sat in for an African savanna. There is now a hiking trail in the area named "The Bwana Trail" to denote the locations used in Bwana Devil. Authentic African footage shot by Arch Oboler in 1948 (in 2D) was incorporated into the film. Ansco Color film was used, instead of the more expensive and cumbersome Technicolor process. Lloyd Nolan appeared in a prologue for the film. The film was given Code approval in two dimension but not in three dimension due to a kissing scene. Eventually approval was given. Release The film premiered under the banner of "Arch Oboler Productions" on Wednesday, November 26, 1952, with a twin engagement at the Hollywood Paramount Theatre and the Paramount Theatre in downtown Los Angeles. It opened to the public the following day. At all U.S. screenings of feature-length 3D films in the 1950s, the polarized light