THE ADVENT OF VIDEO HAS LED TO older movies being taken for granted. A mere 20 years ago, you'd rush home to see your favorite film when it appeared on TV. Given the lack of repertory houses, it was your only chance to see classic fare like Citizen Kane or Some Like It Hot.

Now, whenever a director dies or you want to brush up on film history, all it takes is a trip to the local video store. Cable TV has made a further dent: Why bother renting a film when it's turning up on American Movie Classics this month?

Still, it wasn't any surprise that when The Third Man played this year's Seattle International Film Festival, it drew nearly a full house at the refurbished Cinerama. The video format might be readily accessible, but it comes up short in another key area--presentation. Movies were made to be seen on a large screen--a fact that is especially pertinent in the case of Carol Reed's The Third Man.

The Third Man found instant acclaim upon its release in 1949, winning Best Film awards in Britain and at Cannes. Robert Krasker's stunning cinematography won an Oscar, and the distinctive score by Anton Karas won him worldwide fame. For its 50th anniversary, The Third Man has been re-released in a restored director's cut that adds 11 minutes to the film. Krasker's imaginative use of lighting and shadow is dazzling, and atmospheric touches conjured up by Karas' music creates a cinematic experience that can't possibly be duplicated by a screening on TV.

The story is deceptively simple. Set in war-torn Vienna, a brash American writer, Holly Martins (Joseph Cotten), arrives to take up a job offer from his childhood friend, Harry Lime (Orson Welles). On arriving in Vienna, Martins learns that Lime is supposedly dead--having been hit by a truck--but as he questions Lime's friends, he becomes increasingly suspicious. Two of the three men who carried Lime's body to the sidewalk are accounted for, but the third has apparently disappeared. Martins also becomes outraged when he learns that Vienna's military police had tagged Lime as a profiteer on the black market. He is then determined to solve the mystery himself, and clear his friend's name.

Screenwriter Graham Greene first saw Martins and Lime as Britons, but Americans were ultimately cast in order to make the film more "American-friendly." Greene nonetheless tweaks his characterizations. As Martins, Cotten loudly blunders along with the self-assured arrogance that Americans are justly known for overseas. The film exudes an aura of cynicism in casually tossed-off observations ("They don't make heroes anymore") that make Martin--a man accustomed to the comforts of the New World, who is unable to come to terms with the demands of the Old World--all the more naive. Conversely, Lime's emotional detachment allows him to exploit the Old World, selling useless, watered-down penicillin to the masses he contemptuously refers to as "dots" (Welles also wrote some of his own dialogue).

The film's other characters are drawn in quick, confident strokes. Major Calloway (Trever Howard), head of the British military police, has a dry wit that underscores his devotion to duty. Lime's girlfriend Anna (Alida Valli) captures the vulnerability of a woman whose past hurts have taught her not to expect too much from life. Even the bit players milk their lines for every nuance, as a doctor does when he frostily reminds Martins of his name's correct pronunciation--"Vinkle!"

Vienna has its own character. Greene visited the city before writing his script, essentially scouting out locations. Even Sacher's, the hotel where he stayed, provides a setting. Piles of rubble line the cobblestone streets, emphasizing Vienna's world-weariness.

Other settings are more dramatic, such as the stone tunnels and chambers of Vienna's sewer system, where the film's climactic chase scene is set. Martins and Lime finally meet in one of the film's most famous scenes, when they ride a Ferris wheel in a deserted amusement park.

At night, eerie shadows appear, and a doorway offers the location for Lime's beautifully-timed entrance; first the tips of his shoes are seen, and then a door opens and a single ray of light illuminates his face.

The film's conclusion takes an unexpected turn, and is something no mainstream Hollywood movie would dare use today. At the SIFF screening, small gasps could be heard from people who clearly expected a more formulaic conclusion. Co-producer David O. Selznick and even Greene suggested a more upbeat ending. But Reed insisted otherwise, and his view prevailed--providing the perfect ending for this stylish and elegant film.