"Artscope"--the after-dark cinema-happening running nightly on the Mall in front of the National Air and Space Museum--is uniquely suited to its site. Like the art museums around it, this visual spectacle--a circle of 16 screens receiving simultaneous projections of 100 short films on art per night--is the brainchild of a collector who accumulates on a large scale.

For 20 years, Englishman Anthony Roland has been collecting (and making) films on art. He rents or sells them to museums and others through a commercial enterprise known as the Roland Collection. "Artscope," which runs for two hours, is something he dreamed up for last summer's Edinburgh International Film Festival. This is its American premiere.

What "Artscope" amounts to is a three-dimensional catalogue of Roland's film collection.

Some catalogues are more interesting than others, and Roland's is less interesting for the quality of its contents than for the unusual nature of its packaging. Looking like a campfire-circle for culture vultures, it consists of 16 6-x-8-foot screens centered by a giant trailer from which strong, dusty beams of light carry the images to their destinations. People choose where they'll sit on their hand-carried plastic seats, and though admission is free, can rent earphones (for $4 at the site) that tune in on the soundtracks.

A program handed out at the tent entrance promises films on everything from prehistoric cave drawings to Botticelli paintings, Michelangelo sculpture, Art Nouveau architecture and Max Ernst collages. But eager beavers should resist the impulse to waste time checking off what they'd like to see--or arguing about where they're going to sit--since once the show begins, the lights go out, making the programs impossible to read. And since many of the films tend to be boring, uninformative, inappropriately scored or far too casually written, there's a great deal of milling around. In the end, few make their way from one screen to another based on anything more than whim or impulse.

Roland makes much of the fact that he is only interested in films that are works of art in themselves. But those who sit themselves down to concentrate on any single film may end up feeling that his criteria are the show's worst flaws. There are more than 60 filmmakers represented, so no blanket judgement can be fairly issued. Some viewers were most taken with a film on Turner that had no words; others were most annoyed with a particularly unsatisfying cinematic study of Michelangelo's Medici Tomb. In two hours, I saw no single film I shall remember.

But the atmosphere is glorious, and just sitting on the Mall at night can be a most agreeable experience, especially for those who've had the good sense to bring good food and good company along. Art lovers watching an image of Rembrandt superimposed on the National Gallery fac,ade, however, are likely to be left thinking they'd rather be inside looking at the real thing. The show begins at 9:15 every night through Aug. 16.