Video art explores many aesthetic horizons in new exhibition.

Video art continues to come of age. A few years ago it was a medium for tinkerers, dabblers, and experimenters. For every aesthetic discovery there were many false starts and rediscoveries of the obvious.

Little by little, however, the new technology has attracted talents to match its flexibility and scope. Its audience and exposure are growing, and it is being viewed with new seriousness by the art community.

The latest sign of this new respectability is a large show called ''New American Video Art: A Historical Survey, 1967-1980.'' The show, mounted by the Whitney Museum of American Art in Manhattan, where it recently finished a three-week run, is being prepared to travel to museums and art centers throughout the United States under a grant from the National Committee of the Whitney. (Although dates and places are still being arranged, a firm engagement has already been set for next March 5-31 at the Sarah Campbell Blaffer Gallery at the University of Houston.) It's billed as the largest and most comprehensive touring show of its kind ever assembled by a major art museum.

A look at the show's program confirms the wide range of artists who have been drawn to video. Ed Emshwiller and Stan VanDerBeek are celebrated filmmakers, for example, while Vito Acconci and Richard Serra are sculptors, and Joan Jonas is an innovative ''performance artist.'' Others, including video pioneer Nam June Paik and the team of Kit Fitzgerald and John Sanborn, have done all their best-known work in the new medium.

The range of video styles has become as diverse as the artists themselves. Jonas's 1976 ''I Want to Live in the Country (and Other Romances)'' is a strange pastoral meditation. John Baldessari's 1972 ''Inventory'' is a ''conceptual'' work in which the placing of objects on a table becomes a witty comment on the medium's relationship to artist and viewer. Bill Viola's 1979 ''Chott-el-Djerid (A Portrait in Light and Heat)'' shapes desert mirages into a hallucinatory tone poem. Davidson Gigliotti's 1979 ''After Montgolfier'' begins with a rush of color and motion so dazzling that it's unidentifiable - until the camera pulls back to show it's a maze of tree branches lining the path of a swiftly ascending balloon. Other examples would show equal variety.

The 38 works in the Whitney show are ''single channel'' videotapes, made for viewing on a regular TV screen. (The museum provides a dimly lighted viewing area that allows for coming, going, and long-term gazing, according to one's interest and capacity.) Some video artists also employ multiscreen or ''installation'' formats, using TV images as elements of sculptural or environmental works. Although such pieces are not included in this, the museum's New American Filmmakers Series has long championed this avenue of exploration.

In recent years there has been hopeful talk of cable TV providing a huge new outlet for video art. According to this theory, giant cable systems will need enormous amounts of ''product'' to fill dozens of new channels and will find some of this in the work of serious video artists. Some activity has taken place along these lines, especially on the rock-music MTV network, where some video artists have ventured.

For the most part, though, cable firms still turn largely to traditional, tried-and-true kinds of programming, and video artists as a group have not found themselves in sudden, overwhelming demand. Thus museums and special video showplaces (such as the respected Kitchen Center in Manhattan) remain the most important venue for video artists eager to show their work and advance the state of the art. This touring show, organized by film and video curator John G. Hanhardt, is a laudable step forward in this direction. One hopes it spawns many sequels.