Video art is a relative rarity on Washington's art scene, so Troyer Gallery's inclusion of a pair of videos in its edgy group show titled "Momentum" is a welcome change of pace. While the art form is seldom seen here, it is a hot medium in Manhattan and elsewhere. Some important galleries show videos, and some important museums and private individuals have begun collecting them.

It's a remarkable phenomenon because a great deal of video art is awful--boring, incoherent, visually uninteresting, technically weak and overly long--like a cross between bad TV, bad art and bad home video. But when a video succeeds, like Michael Joseph's "Above and Beyond," which is the strongest piece in this terrific show, the viewer gets hooked into an experience that is unique, powerful and unlike any other art form.

Joseph, a 32-year-old sculptor, photographer and video artist from New York City, shot the short piece, which takes place on the Brooklyn Bridge, earlier this year. In deceptively simple style, "Above and Beyond" documents a walk from Brooklyn toward Manhattan that takes a bizarre twist. The hand-held camera bounces from side to side in step with Joseph's stride as he trudges up the shadowed stairs to the bridge's pedestrian walkway and heads toward the backdrop of skyscrapers punctuating the horizon.

Joggers and other pedestrians flow past in both directions as the bridge's symmetry, grace and solidity frame the scene, which is set to a mix of music and ambient sound. Then, with a jump-cut, the everyday rhythms and vistas vanish. The camera looks out toward the harbor as Joseph walks along one of the bridge's mammoth supporting girders. He reaches the end, aims the lens straight down at the East River, then lets the camera fall. It tumbles through space but continues functioning after splashdown, bobbing gently in the current, rising and falling in the same cadence as the artist's stride. Then the screen goes black.

While suicide is the obvious reference, Joseph's video, which runs about five minutes, is so packed with beautiful, evocative imagery on so many levels that it can't be characterized as being just about taking one's own life. It can, for example, also be seen as an allegory for a young artist's struggle to make the transition from Brooklyn to the big time.

There's a certain dark humor in watching the real-life New Yorkers on the bridge, so utterly self-absorbed that they don't even notice the man with the video camera, let alone the glorious interplay of light and shadow that is all around them. And in the end, there's a hint of resurrection. Just before the camera goes overboard, a small boat can be seen below the bridge. In it are friends of the artist. That camera lives on.

Whether that's a good thing is debatable. "Now Playing," from 1997, is Joseph's other video on display here. It shows him in a theater, taping a scene from a movie called "Spirit of the Beehive." Ah, the show within the show within the show, etc. That's not new, not interesting and not worth watching.

Fortunately, that undistinguished effort is more than compensated for by fine work from the five other artists in the show. All are relatively young, and their work is promising.

Sculptor Luisa Kazanas uses a variety of industrial materials, including cast urethane, paint, wax, Plexiglas and gel caps, to produce glossy works that look like biological mutations based on American life in the late 1990s.

In one large, bright red piece commenting on biotechnology, a pair of legs extends from the top of an egg shape studded with lumps that calls to mind naval mines or alien life forms from early science fiction films. Kazanas's three tiny sculptures enclosed in gel caps, which are titled "36-24-36," "GS-14" and "Mrs," are, respectively, bitingly funny looks at beauty, career and matrimony.

Rhona Bittner's color photographs from her series titled "Circus" revolve around the alienation of the individual in a mass society. Her circus performers stand alone in the spotlight in their colorful costumes, surrounded by darkness. They seem like fragile, exotic things, human orchids blossoming briefly before they disappear into blackness.

A similar fragility can be seen in Kim Hunter's manipulated, black-and-white photographs of children. She uses various materials--paint, chalk and charcoal--to make an overlay that provides narrative context on her poignant photographs of young, slightly forlorn-looking girls. By putting numbers and letters on the photograph, Hunter conveys the sense of a young person trying to develop intellectual and emotional systems for coping with a tough, hostile world.

Systems, both technical and aesthetic, are the driving force in Haegeen Kim's beautiful drawings on steel, as well as her untitled sculpture that is actually a drawing machine, endlessly producing two perfect circles, one drawn in graphite on the wall, the other drawn in ink on a piece of Plexiglas. It's a wonderful work, combining the hum and force of 20th century technology with late Renaissance lyricism.

The most overtly natural sculpture in the show is by Andrew Moe, who produces lively pieces full of energy and motion from wood, wire, reeds and steel. A few of Moe's efforts are reminiscent of Martin Puryear's work but lack his evocative and emotional impact.

Momentum, at Troyer Gallery, 1710 Connecticut Ave. NW, Wednesday-Saturday, 11 a.m.-5 p.m., through Aug. 21. 202-328-7189..

CAPTION: An untitled sculpture by Haegeen Kim that's actually a drawing machine, endlessly producing perfect circles.

CAPTION: Luisa Kazanas's bright red commentary on biotechnology is part of the group show "Momentum."