MAYBE IT'S his red beard; perhaps it's always itching. Or his gray wool trousers surely they set a fellow on edge.

No. matter.

Ridley Scott presents himself as a forthright, damn-the-torpedoes type, given to epithets like "God bless his cotton socks," a man who tells you right out what's on his mind. And right now what's on his mind are commericals.

His commericals.

"I run into snobbism about them all the time, but I refuse to knock them, I refuse to agree," he says stoutly. "People don't know what the - they're talking about. I will show them to anybody and they stand up." So there.

If it weren't his nature Scott wouldn't be so devilishly pugnacious, because things are rather going his way. His first feature film, "The Duellists," now at the Fine Arts, opened to more than kindly reviews in New York (Pauline Kael said of one sequence: "This is either the luckiest shot a beginner movie director ever caought or the most entranced bit of planning a beginner ever dared"), and even people who think the story line is not as strong as it ought to be are taken by the film's impeccable, almost too-good-to-be-true look, all the more remarkable because it was brought in at an astonishingly low cost of $1.4 million. Including a check for 25 British pounds to cameo actor Albert Finney, delivered framed with the note, "Break glass in case of emergency."

But since Scott is 39, not the youngest age at which to begin directing, and since more than a few of the earlier years were spent making close to 3,000 commericals from his home base in England, people are naturally curious. "There are no specific routes on directing," he says, "and though it took me a bit longer than I expected, it wasn't through lack of trying. You know your nose, try to make the right decision. God knows how you do it.

"Commericals just appealed to me," he says when asked about the not-so-dark past. "There's a finesse you can bring to bear, especially in Europe, that is difficult for Americans to relate to. Commericals here are the curse of American TV, the worst; or as you call it, the pits. They're done with the use of a bludgeon, with the idea that if you push hard enough people will buy, something I don't believe."

Scott likes the "humorous, dramatic little filmlets" like the VM ad done by a competitor which answers the question "How does the snowplow operator get his snowplow?" (Three guesses.)

He worked often in the United States, dragging bags of film "like - ing coal sacks" and disregarding the well-meaning advice of various executive producers who told him that for an incipient feature film director this would never do.

"I settled on my own theories," he says unflinchingly. "I thought I did commericals really well and I couldn't go back. It was either make or break with them."

It turned out to be "make." Producer David Puttnam saw some of Scott's work, put together the deal with Paramount for "The Duellists," and now deftly defends the man's commerical background as follows: If you're not putting film (See RIDLEY, K12, Col. 1> through a camera you're not a director, you're a coffee drinker."

Based on a Joseph Conrad short story about two men who duel obsessively (not to say compulsively) across the map of Napoleonic Europe, "The Duellists" came in slightly over its $1.1 million budget but still ranks as the niftiest visual display that amount of money has bought in years.

Scott, who noted that Stanley Kubrick used commerical photographers as second-unit people in the equally dazzling, if more frightfully expensive "Barry Lyndon," says that it was precisely his work on commercials that made his first feature look so good.

"Making things beautiful, this is what I do well, this is what I was good at for 10 years," he says, adding that he even served as his own camera operator in order to get exactly what he wanted. In addition, commerical work "teaches you to organize yourself, your head. There's no creativity unless you have everything you require, whether it's 12 camels in Times Square or whatever. You have to preconceive what you do."

Besides organization the film's minusucle cost is attributable to the fact that, as Scott bluntly puts it, "everyone worked. There was not one passenger. Both David and I ostentatiously lugged things, really ran places. There can be no argument when it starts from the top. No one wants to be eating alone in the corner."

Not even, it turns out, the electricians, or sparks as they are called over there, who, says Scott, "had - all to do. So we used them as extras. All those frozen dead bodies in the Russian scenes, they're sparks!"

Yes, it all looks beautiful, but might not it look in fact too beautiful for its own good? Might not the film's mere words be swamped in a languid sea of imagery? Before Scott can answer, producer Puttnam - what else are producer's for? - gallantly steps in.

"The new result might be slightly overbalanced, perhaps the script isn't strong enough to balance out," he admits, "but a director works instinctively. Could a painter paint less well, could Rembrandtdo less than his best?"

The defense rests.