The Biograph is accepting entries for its seventh edition of "Expose Yourself," a two-day showcase of recent work by local filmmakers. The selections will be shown on the evenings of Monday and Tuesday, Dec. 12 and 13, with cash prizes and theater passbooks going to the three pictures judged most interesting and/or diverting. All entries must be submitted by Friday, Dec. 2. They may be sound or silent, but they must be in 16mm. For further information, contact Jef. Hyde at 338-0707.

The Key has scheduled a preview of its next attraction, the animated feature "Allegro non tropo," reputed to be an elaborate homage to "Fantasia," on Thursday at 10:15 p.m. The movie begins a regular commercial engagement on Friday. "First Love," a collegiate love story co-starring William Katt and Susan Dey and directed by Joan Darling, also opens Friday, at several area theaters, following a preview tonight at 7:30 at the Springfield Mall.

"Silver Bears," a romantic adventure comedy starring Michael Caine as a financial wizard aided and obstructed by characters portrayed by Cybill Shepherd, Louis Jourdan, Stephane Audran, David Warner, Tom Smothers and Martin Balsam, opens Friday, Nov. 18, at area theaters. Ivan Passer directed from Peter Stone's adaptation of a novel by Paul E. Erdman. Pasolini's "Salo," derived from the Marquis de Sade's "120 Days of Sodom," a self-defeating source for a movie if there ever was one, has been booked at the K-B Janus, probably to follow the current attraction, "The Good and the Bad."

With "Iphigenia" opening today at the West End Circle, "Outrageous" shifts to the Inner Circle. Ettore Scola's, "We All Loved Each Other So Much," which recently vacated the Outer Circle after an extended run, reappears today on a multiple sub-run. While awaiting the Monday, Nov. 14, opening of one of the year's best American pictures, Herbert Ross' "The Turning Point," the Dupont Circle is featuring a series of David O. Selznick revivals.

The University No. 3 in Fairfax will host a showing of student films sponsored by two American University students, Eric Young and Gary Gershowitz, Sunday evening. Admission will be free. Call 250-7265 for estimated starting time and titles.

Sheldon Tromberg is planning another seminar course for prospective movie writers, "An introduction to Feature Motion Picture Screenwriting," on or about Tuesday. There are five weekly sessions lasting three hours each. For details, call 966-7799.