question: Were both Ted Tetzlaff and David Siegel film actors?
answer: no
context: Title: Time Bomb (1953 film)
  Passage: Time Bomb is a 1953 British-made MGM post-war thriller film written by Kem Bennett and directed by Ted Tetzlaff.  It starred Glenn Ford and Anne Vernon.  In the US it was released under the title Terror on a Train.
  Title: World Premiere (film)
  Passage: World Premiere is a 1941 American comedy film directed by Ted Tetzlaff and written by Earl Felton.  The film stars John Barrymore, Frances Farmer, Eugene Pallette, Virginia Dale, Ricardo Cortez, Sig Ruman and Don Castle.  The film was released on August 21, 1941, by Paramount Pictures.
  Title: The Young Land
  Passage: The Young Land is a 1959 American Western drama film directed by Ted Tetzlaff starring Patrick Wayne and Dennis Hopper.  The cinematography was by Technicolor developer Winton C. Hoch and Henry Sharp.  The film was distributed by Columbia Pictures Corporation.
  Title: Ted Tetzlaff
  Passage: Dale H. "Ted" Tetzlaff (3 June 1903, Los Angeles, California – 7 January 1995, Sausalito, California) was a noted Academy Award-nominated Hollywood cinematographer active in the 1930s and 1940s.
  Title: David Siegel (screenwriter)
  Passage: David Siegel is an American film director, screenwriter and producer, and part of a long-standing writing-directing-producing team with filmmaker Scott McGehee.
  Title: Johnny Allegro
  Passage: Johnny Allegro is a black and white 1949 American film noir, starring George Raft, Nina Foch, Will Geer, and George Macready.  An ex-gangster (Raft) working as a federal agent runs afoul of a crime lord (Macready) who enjoys hunting humans for sport.  The picture was directed by Ted Tetzlaff and produced by Columbia Pictures.
citations: David Siegel (screenwriter) Ted Tetzlaff