In Rome, the film event of the summer was the three-day engagement of Abel Gance's 1927 silent masterpiece, "Napoleon," which took place earlier this month. The film was shown on a screen mounted on the Arch of Constantine in the shadow of the Colosseum. As the moon rose over the ancient arena, a sold-out crowd in an open-air piazza and a thousand eavesdroppers packed onto the slopes of the Palatine and Quirinale hills sat enthralled by the epic. The audience treated the silent film as an opera, giving standing ovations to particularly masterful sequences of shots . . .

When the film went into its multi-image, triple-projector finale, the audience response was like the cannons going off at the end of the 1812 Overture . . . Another large ovation went to Carmine Coppola, who led the orchestra through his three-hour score . . . The film, which has been seen in limited engagements in New York, L.A. and Chicago is now rumored for a D.C. showing sometime early next year . . .

* Washington's own Robert Prosky is scoring points with overseas critics. This is from a review in the London Observer of the film "Thief" (released as "Violent Streets" abroad): "What is perhaps most memorable about his director Michael Mann's film, incidentally, is a quietly understated performance by Frank sic Prosky as a smiling suburban gang-boss with the kindly face of Jack Jones and the instincts of Himmler . . ."

* Casting News: Laraine Newman, formerly of "Saturday Night Live," replaces Swoosie Kurtz in "Fifth of July" around Oct. 6 . . . Mark-Linn Baker, who appeared as Florizel in "The Winter's Tale" at Arena Stage two season's past, stars as a Mel Brooks-like writer in "My Favorite Years." Richard Benjamin is directing this film about the Golden Age of Television . . .

* Popular Movies From All Over, Part 1: In New York, the most popular movie last week was "Mommie Dearest," which grossed more than $1.3 million. Reports have the audiences responding to the movie in the call-and-reponse tradition of "The Rocky Horror Picture Show." . . . Part 2: In Japan, a film called "The Killing of America," a documentary on crime here, grossed $1.2 million . . .

* Greece, the setting for much of the popular James Bond film, "For Your Eyes Only," is becoming a favorite spot for filmmakers (in addition to half the population of Europe). This summer Paul Mazursky filmed "Tempest" starring John Cassavetes in Athens and in the Peloponnesus. Randal Kleiser, who directed "The Blue Lagoon," was in the islands directing "The Greek Project."