Question: What profession did Charles Brabin and Karl Freund share?

Context articles: Susanne Lautenbacher
Burning Daylight (1928 film)
Twinkletoes
A Wicked Woman
Moonlight and Pretzels
Karl Freund
While New York Sleeps
Charles Brabin
The Valley of the Giants (1927 film)
Blind Wives

Susanne Lautenbacher (born 19 April 1932, in Augsburg) is a German violinist.
 She studied violin with the Munich-based violin pedagogue Karl Freund (first violin of the Freund Quartet) and later with Henryk Szeryng.
 She was a prizewinner in the early years of the Munich ARD Violin Competition.
 On some early recordings her name appears as Suzanne or Susi.
Burning Daylight is a 1928 silent dramatic action adventure film directed by Charles Brabin and starring Milton Sills and Doris Kenyon, a real-life married couple.
 It was produced and distributed by First National Pictures and based on a novel by Jack London.
 It was previously filmed by Metro Pictures in 1920.
Twinkletoes is a 1926 silent film romantic drama directed by Charles Brabin and starring Colleen Moore.
 The film, as with most of Moore's vehicles at this time, was produced by her husband John McCormick with the couple distributing through Moore's resident studio First National.
 This film is one of Moore's surviving films from the late silent era and is available on DVD.
A Wicked Woman is a 1934 drama film starring Mady Christians as a woman who kills her abusive husband to protect her family and builds a new life to raise their four children.
 It was directed by Charles Brabin and also starred Jean Parker and Charles Bickford.
 It was based on the novel "Wicked Woman" by Anne Austin.
Moonlight and Pretzels is a 1933 American Pre-Code musical film directed by Karl Freund about a man who puts on a Broadway show.
 The film was released by Universal Studios, and featured Mary Brian and William Frawley, best known as "Fred Mertz" on "I Love Lucy"; Freund was a cinematographer for "I Love Lucy".
Karl W. Freund, A.S.C. (January 16, 1890 – May 3, 1969) was a German Jewish cinematographer and film director best known for photographing "Metropolis" (1927), "Dracula" (1931), and television's "I Love Lucy" (1951-1957).
 Freund was an innovator in the field of cinematography and is credited with the invention of the unchained camera technique.
While New York Sleeps is a 1920 American crime drama film produced by Fox Film Corporation and directed by Charles Brabin, who was the husband of actress Theda Bara.
 The film tells three distinct episodic stories using the same actors, Estelle Taylor and Marc McDermott.
 Long thought to be a lost film like many other Fox Film productions from this period, a copy of this movie is now in the collection of the UCLA Film and Television Archive.
Charles J. Brabin (April 17, 1882 – November 3, 1957) was an American film director and screenwriter.
The Valley of the Giants is a 1927 silent film adventure directed by Charles Brabin and starring Milton Sills and Doris Kenyon who were real-life man and wife.
 It was based on a novel by Peter B. Kyne.
 First National produced and distributed the film having gained the screen rights to the story from Famous Players-Lasky and Paramount.
 Paramount had made a version of the novel in 1919 with Wallace Reid.
 A copy of this film survives at the UCLA Film and Television Archive.
 It is also listed as existing in an incomplete print at the Library of Congress.
Blind Wives is a 1920 American silent drama film produced and distributed by Fox Film Corporation and directed by Charles Brabin.
 The film reunites director Brabin with the stars of his previous success "While New York Sleeps", Marc McDermott and Estelle Taylor.
 The film is based on a 1914 Broadway stage play by Edward Knoblock, "My Lady's Dress" which starred Mary Boland.
 This film survives in prints held by George Eastman House and by the Library of Congress.