GOING TO THE MOVIES : BEFORE HIS TIME : THIS IS ORSON WELLES, <i> By Orson Welles and Peter Bogdanovich edited by Jonathan Rosenbaum (HarperCollins: $30; 576 pp.)</i>

Camera angles, admits the normally blustery Orson Welles, are “the only thing I’m certain of. I’m never certain of a performance--my own or the other actors’--or the script or anything. . . . But to me it seems there’s only one place in the world the camera can be, and the decision usually comes immediately.

“If it doesn’t come immediately, it’s because I have no idea about the scene, or I’m wrong about the scene to begin with.”

This is Welles speaking with fellow filmmaker Peter Bogdanovich in “This Is Orson Welles,” a series of conversations that reached printed form by almost as tortuous a route as much of Welles’ own work. In skillfully conducted and relentlessly persistent interviews, Welles’ brilliant analysis of his own and others’ works goes a long way toward easing the buffoonish image Welles had gained in his later years when, in desperate attempts to raise funds for dream film projects, he appeared regularly in comedy skits on “The Dean Martin Show” and as commercial spokesman for low-priced wines.

It was in the 1970s, during the time he was often appearing on television, that rumors about this redeeming book surfaced. Like so many projects in Orson Welles’ troubled career, this autobiographical examination of his work in films remained unfinished at the time of his death in 1985. By then, Welles--who had made the most audacious directorial debut in film history with “Citizen Kane” in 1941--had long since been declared an undesirable in Hollywood, and when he could work as a director it was usually in Europe. Almost all the movies he had managed to complete since his debut had suffered from massive re-editing against his wishes, inadequate budgets, severely limited distribution or all of the above. He had been unable to complete several projects he had started filming, ranging from a retelling of “Don Quixote” to a thriller based on the novel “Dead Calm.”

Although the films he did manage to finish show incredible mastery of the medium, his inability to complete many he started only served to set in stone his reputation as an irresponsible, uncompromising dreamer.

His problem was not, as some argue, that Hollywood hates great artists--Hitchcock made wonderfully innovative and intelligent films, yet he was in great demand. But the bottom line for Welles was the bottom line: His films never did well at the box office.

If Welles had been a brilliant painter (which in the book he says was a lifelong ambition) or novelist, he might have left behind many more great works. But Welles’ art form is hugely expensive and requires not only the cooperation but also the enthusiasm of studio bosses and financiers. That he was not more successful at courting them is a tragedy, both for him personally and for the art form, but Welles must shoulder much of the blame. He must have realized, on some level, that the powerful William Randolph Hearst would not take kindly to the elements suggested by his life in “Citizen Kane” and would do his best to suppress the film. But Welles was brash. In this book he proudly talks about how at the time the film came out he taunted Hearst in person.

Nonetheless, there should at least have been some room for Welles’ art, even within the studio system. But it was rare that anyone with clout would support him.

A notable exception was Charlton Heston, who got Welles the job of directing the 1958 thriller “Touch of Evil” with just an offhand remark. At the time the film was being planned at Universal Studios, Welles had been approached only to act in it. “They called up Chuck Heston and said, ‘Here’s a script--we’d like you to read it. We have Welles,’ ” Welles says in the book. “And he misunderstood them and said, ‘Well, any picture that Welles directs, I’ll make.’ So they got back on the phone quick and said to me, ‘Do you want to direct it?’ ”

That movie amply showed he could make a film that was both innovative and entirely accessible to mainstream audiences. Unfortunately, Universal released it as part of a double bill without press screenings or fanfare.

At the time of the interviews for this book, 1969-1972, it looked as if Welles might finally be ripe for a comeback. One of his fabled projects--an original story called “The Other Side of the Wind,” starring John Huston as an aging Hollywood director--was reportedly in rough-cut stage and almost completed. And the book, to be co-written by his friend Bogdanovich, would finally set the record straight about his endeavors.

But the two projects went the way of so many Welles ventures.

Except for a couple of tantalizing--and now legendary--clips shown in 1975 on the night the American Film Institute gave Welles a Life Achievement Award, “The Other Side of the Wind” never received a public screening. To this day it remains mired in legal and financial constraints.

The book project got as far as to be a 1,301-page manuscript, but before the text could be honed down to a publishable form, the authors’ lives diverged; eventually, they became estranged. The book’s rebirth is largely due to the efforts of film scholar Jonathan Rosenbaum, who pieced together what he considered the best material (and, in a discreet section of editor’s comments, deflates some myths Welles perpetuates about himself).

It’s no surprise that Welles emerges as a brilliant and provocative, if sometimes petulant and egotistical, conversationalist. But he also gratefully acknowledges and discusses in detail the part that others, including cinematographer Gregg Toland, composer Bernard Herrmann and various crew members, made to his films. And at times the forceful Welles comes off as painfully insecure.

He finds acting as mysterious a process as do many lesser directors, but his comments on the subject do give clues to how he chose to play his own roles: “Cagney was one of the biggest actors in the whole history of the screen. Force, style, truth, and control--he had everything. He pulled no punches; God, how he projected!

“And yet nobody could call Cagney a ham. He didn’t bother about reducing himself to fit the scale of the camera; he was much too busy doing his job. Toshiro Mifune: His movie performance would register in the back row of the Kabuki.”

The most arresting bit of news in the interviews concerns the famed 1938 “War of the Worlds” radio broadcast. The H. G. Wells invasion-from-Mars adaptation was read in realistic, documentary style, as if it were a breaking story interrupting a music program.

Thousands of listeners were taken in by the hoax; many took to the streets in panic, and a woman in Pittsburgh was stopped from taking poison while she screamed, “I’d rather die this way”! The next day Welles, who for years maintained he had learned of the disaster from the next morning’s newspaper, apologized profusely at a press conference, saying it was never meant to stir up that reaction.

But here Welles finally confesses that it was the aim of the show to terrorize listeners, and that the radio theater group had been aware of all the events--especially since the police arrived in the studio in mid-broadcast. The effect, in fact, had been “merrily anticipated by us all,” Welles said. “The size of it, of course, was flabbergasting.”

He goes on to explain why he had misrepresented the incident through the ensuing decades.

“There were headlines about lawsuits totaling some $12 million. Should I have pleaded guilty?”

Maybe he should have. Welles’ penchant for storytelling served him well on talk shows and in fine restaurants where he so often held court. But his big performances in life undercut the acceptance of his artistry that he so dearly craved. While there have been several previous Welles biographies, this conversational book confirms that he probably would have been the greatest dinner companion one could ever hope for. But it also serves as a kind of memorial to a great body of unrealized work that will unfortunately never enrich our lives.