Allan Franklin Arbus (February 15, 1918 – April 19, 2013) was an American actor and photographer. He is most known for his role as psychiatrist Dr. Sidney Freedman on the CBS television series M*A*S*H.
Early life:
Arbus was born in New York City, of Jewish background, the son of stockbroker Harry Arbus and his wife Rose (née Goldberg). He attended DeWitt Clinton High School in the Bronx, where he first developed an interest in acting while appearing in a student play.

Arbus was also a music lover. Before becoming an actor, he was reportedly so taken by Benny Goodman's recordings that he took up playing the clarinet.

Photography career:
During the 1940s, Arbus became a photographer for the United States Army. In 1946, after completing his military service, he and his first wife, photographer Diane Arbus (née Nemerov, whom he had married in 1941), started a photographic advertising business in Manhattan. Arbus was primarily known for advertising photography that appeared in Glamour, Seventeen, Vogue, Harper's Bazaar, and other magazines, as well as the weekly newspaper advertising photography for Russek's, a Fifth Avenue department store owned by Diane's father. Edward Steichen's noted photo exhibition The Family of Man includes a photograph credited to the couple. The Arbuses' professional partnership ended in 1956, when Diane quit the business; the couple formally separated three years later. Allan Arbus continued on for a number of years as a solo photographer, but was out of the business by the time the couple divorced in 1969.

Diane and Allan Arbus's studio/living quarters were at one time at 319 East 72nd Street in New York City. Their neighbor and friend was Robert Brown, an actor on the TV show Here Come the Brides.

Acting career:
After the breakup of his first marriage and the dissolution of his business, Arbus decided to leave photography behind and pursue a new career in acting. In 1969 he moved to California. His new career took off after he landed the lead role in Robert Downey Sr.'s cult film Greaser's Palace (1972), in which he appears with Robert Downey, Jr. (who would go on to star as Diane Arbus's muse in Fur, a fictional account of the end of the Arbuses' marriage). Arbus also starred opposite Bette Davis in Scream, Pretty Peggy in 1973, and was featured as Gregory LaCava in W.C. Fields and Me in 1976. These roles led to his casting as Maj. Sidney Freedman on M*A*S*H, although in an early episode, "Radar's Report" (1973), he was called "Milton Freedman".

Arbus's work on M*A*S*H helped his career as a character actor, and he eventually appeared in more than 70 TV shows and movies. He appears briefly in the 1973 film Cinderella Liberty as a drunken sailor; another 1973 film, Coffy (starring Pam Grier), features Arbus as a drug dealer with strange sexual needs; in the 1978 movie Damien: Omen II, he plays Pasarian, one of Damien's many victims in The Omen trilogy.

Arbus is far better known for his television work, which includes over 45 titles and works as recent as Curb Your Enthusiasm in 2000. Among Arbus's non-M*A*S*H TV work are guest and recurring roles in such television series as Law & Order, In the Heat of the Night, L.A. Law, Matlock, Starsky and Hutch, and Judging Amy.

Personal life:
Allan and Diane Arbus had two children, photographer Amy Arbus and writer and art director Doon Arbus. The couple separated in 1959 and divorced in 1969, two years before Diane Arbus's suicide in 1971.

Arbus married actress Mariclare Costello in 1977. The couple have one daughter, Arin Arbus, who is the Associate Artistic Director at Theatre for a New Audience.

Arbus died of congestive heart failure on April 19, 2013, in Los Angeles. He was 95.

Source: wikipedia.org