MAX OPHULS (Max Oppenheimer), who left Germany in the '30s to work in France and then the United States, made stylish films about high-society lives and passions -- including Liebelei, Caught, Vendetta, The Exile, Letter from an Unknown Woman, La Ronde, The Earrings of Madame De and Lola Monte`s. On Tuesday, the Smithsonian Resident Associates shows "Liebelei" (1933), which was shot in Germany; "Letter from an Unknown Woman" (1948, with Joan Fontaine and Louis Jordan) January 19, shot in the U.S.; and "La Ronde" (1950) January 26. All shows start at 8 at the American History Museum's Carmichael Auditorium. Admission is $6.50 ($5 members), for the series $18 ($14). Call 357-3030 for reservations.

This weekend, the National Gallery of Art begins its 54-film "Cinema of the American Avant-Garde" series of works by Paul Strand, Joris Ivens, Man Ray, Maya Deren, Larry Jordan, Stan Brakhage, Hollis Frampton, Bruce Conner and others. The films cover a 64-year period, from Strand's 1921 Manhatta to Su Friedrich's 1984 The Ties that Bind (two Friedrich films, part of the Hirshhorn's "Independent Films" series, will screen in March). Saturday, the series begins with "Manhatta" (9 minutes), The Wave (Strand and Fred Zinnemann, 1936); Ivens' The Spanish Earth (1937), H2O (1929, Ralph Steiner, 14 minutes), Mechanical Principles (Steiner, 1931, 11 minutes), Weegee's New York (Weegee, 1948, 20 minutes) and Helen Levitt's In the Street (1952, 16 minutes). The first shows will be introduced by series organizer and New York University professor Annette Michelson. 737-4215.

The Franc ois Truffaut series continues at the American Film Institute this weekend with Two English Girls (Friday at 6:30, Sunday at 8) and Small Change (Saturday at 3, Sunday at 6). Also on at the AFI this weekend is a double bill of Ben Hecht's His Girl Friday with Cary Grant and Rosalind Russell and 1931's The Front Page. Bernardo Bertolucci's beautifully made (in 1964) Before the Revolution is Saturday at 6 and Monday at 9.

The Truffaut program (showing most of his works), runs through February 23. Here's the schedule: Bed and Board with Love on the Run (Tuesday and Wednesday); Fahrenheit 451 (January 18-19) Jules and Jim (January 22 and 24); The Woman Next Door (January 30-31); The Man Who Loved Women with Such a Gorgeous Kid Like Me (February 4-5); The Story of Ade`le H (February 6-7); The Soft Skin (February 8); Shoot the Piano Player (February 10-11); Day for Night (February 12 and 14); Confidentially Yours (February 19) and The Last Metro (February 23). Call 785-4600. Admission is $4.50, $3.50 for members.