A man stands in an office doorway glaring balefully down a dingy corridor. He looks straight through the seven people clustered around him, through the floodlights, the tangle of cables, the huge camera.

"Red light and bell, please!" someone calls firmly. "No one to use the lift. Nice and quiet, now. Everyone settle down. Action!"

The man stares for a long moment, hatred radiating from his aristocratic face. Then he steps back into the office and closes the door.

"Cut. Thanks very much. This shot ends this sequence. K'you!"

Everybody claps a bit. A makeup womanin jeans picks up her tray and goes away. The soundman unhooks a mike. Chatter resumes. There will be champagne downstairs in half an hour, for the crew has been shooting in this building for six weeks and everyone is sick to death of it. Director John Irvin talks quietly with the actor, Ian Richardson.

The scene they have just made lasted onlu a minute, but they have run through it six times.

Perfection is routine in this sevenpart BBC serialization of John LeCarre's spy novel, "Tinker, Tailor, Soldier, Spy" -- partly because the star, Sir Alec Guinness, demands it of himself, partly because that's the way BBC works.

People are always asking why American television can never seem to do a series the way the British can. Why is it that when we try to produce another "Upstairs, Downstairs," we come up with a "Beacon Hill"?

There are several reasons.

The most obvious is the fact that the BBC doesn't have to worry about sponsors. being government supported. There is no committee of executives dabbling in every artistic decision. Ratings are studied and analyzed but otherwise treated in a way that shocked Americans would call downright disrespectful.

(Irvin and other BBC people thought the series "Washington: Behind Closed Doors" was the best thing American TV has done for years. American audiences didn't think so -- according to the ratings.)

"The editorial line is absolutely clear and fundamental," said Jonathan Powell, who is producing the series for BBC and Paramount for fall screening in Britain. "It is an enclosed world: I can use whatever director and writer I want. There is no interference. It's a question of trust. I don't have to show a thing to anybody at BBC until I have the final cut finished."

As producer, he in turn gives the director great freedom, and when a show runs over budget it's no big thing: He goes to the head of the serials department and asks for more money. There are no controllers running about with clipboards, no censorious viewing of rushes, no crowds of hostile strangers to be sweet-talked.

"I got the idea for this serial in April '72," Powell said. "The first thing was to get an okay from my boss, and then I saw LeCarre, and he approved it in principle. Then we negotiated the rights, commissioned a dramatist, roughed out the costs. Later I wrote up a proper budget, and we all agreed upon it. It's all much more gentlemanly than in America, and there aren't so many people involved."

Another reason why the BBC can't seem to miss with its exported serials is the quality of acting.

"Stars do big parts for us readily," said Powell. "They know they won't be let down by the technical standards or production values. Now this one happens to be the first big thing Guinness has done for television, but in addition to him we have a very starry cast."

Some are far better known in Britain than in America. For instance: Alexander Knox, the Canadian who played Woodrow Wilson some years ago, has come out of retirement to play the gray eminence, Control.Beryl Reid, known to Americans for "The Killing of Sister George," is playing Connie Sachs. Ian Richardson (Bill Haydon) has been a star with the Royal Shakespeare Company for nearly 20 years, has toured the world in everything from Lear to Marat/Sade, did Professor Higgins in "My Fair Lady" on Broadway two years ago.

Michael Jayston (Peter Guillam) had the key role in "Equus" at the Old Vic and has played Custer in Arthur Kopit's "Indians," Laertes, Henry II and assorted crazies in "Beyond the Fringe." (In Who's Who he lists his recreations as "sports and listening to drains.")

There is a third reason for BBC's success, and it is the most fun.It's the all but maniacal attention to detail.

Much of the action takes place in the Circus, an old office building in downtown London. LeCarre's greatest strength is the wry joke he plays on thriller fans: His conceit that all the derring-do of spies, all the gunplay, the chases in souped-up Alfa-Romeos, the baccarat games, the lethal but beddable beauties -- in the end it all comes down to these crummy offices, the airless lair of a moribund insurance firm, smelling of armpits and ashtray fires.

Well, Jonathan Powell found just such a place, an abandoned building on Cork Street in Mayfair. Incredibly, it had once actually been a secret service base, complete with heavy curtains to prevent conversations being picked up by electronic listeners from window vibrations.

The setting is a tribute to LeCarre's authenticity, with its narrow corridors, its Continental-style open elevator with stairs winding around it, its polite grime, its walls the color of dead flesh, its unloved squalor.

So far, there's nothing an American production couldn't have duplicated, given a bit of luck. (A genuine Tudor country house would be something else again.) But wait.

Offices come with three types of floor: Linoleum, rug and wall-to-wall carpeting. BBC has given each character the appropriate floor. You won't see it in the film. But that doesn't matter.

"Just because you don't see their feet, we still give them the right shoes," said director Irvin.

The same with costumes. Most of the characters come from the possessing classes, so they wear expensive Savile Row suits. Some, like the dapper Toby Esterhase, wear them with style and dash. Others, like the tubby Roy Bland, have a slept in appearance, so those suits were left on the floor to be walked over by one and all.

LeCarre customarily writes complete dossiers on all his characters -- where they went to school, what they did before coming into his stories -- and this information was the basis for furnishing each office.

Bill Haydon's cubicle sports Orientalia, opium pipes, Jade statues, old World War II group photos of Montgomery's 8th Army in Africa, the umbrella on the hat rack. Control's office is bigger, brighter, has the coveted carpeting, a picture of the queen, chairs for guests, but little personality.

Someone spent a lot of highly paid time thinking up and finding all this stuff, even to the ragged-edged rugs and the sloppily kept fake archives, cases and cases of them. (They are old BBC records.) It is what a spy would call deep cover. And it is marvelously convincing.

The whole series is being filmed, not videotaped. This is more expensive again, but gives better depth of field, sharper images, more finely honed editing. Many American (and British) TV shows are done in studios with videotape and some film inserts for a touch of class.

"Tinker, Tailor" went to Scotland for two weeks to do scenes set in Czecholslovakia, to Portugal for another two weeks and will wind up in Oxford. The original shooting schedule was 16 weeks, but union slow-downs have stretched that to 20 weeks. They are producing five to six minutes of finished film a day, and the shooting ratio runs about 7 to 1, that is, one foot used for every seven feet filmed. This is respectable even for movies.

"Tinker, Tailor, Soldier. Spy" will be seen in Britain next September. Irvin thinks it is one of Guinness's finest roles -- the drab and brilliant George Smiley -- down to his very walk.

American audiences will have to wait at least a month or two longer to see it. But chances are, it will be yet another sensation in the States, to be succeeded by yet another imitation, committee-built and unmemorable.