Since 1962, Robert Rauschenberg has been experimenting with silk-screened photographic images, applying them to stretched and unstretched canvases, sliding Plexiglas panels and motorized revolving discs. His most recent variation on this theme is "Sling Shots," a set of 11 constructions now on display at the B.R. Kornblatt Gallery.

Each consists of a beautifully crafted rectangular wooden frame, like a window, but with photographic images printed on Mylar and backed with sailcloth where the glass should be. Hanging in front of this are two additional layers of clear Mylar with more silk-screened and lithographed images, some in black and white, others in electric shades of blue, green, orange and red. The whole ensemble is illuminated from the rear by fluorescent bulbs, giving the effect of an oversize light box, and the free-hanging Mylar sheets can be raised or lowered, like shades, by pulling the cord at one side of the box.

The individual elements of each "Sling Shot" -- mixed media, Pop-style imagery and audience participation -- have formed the basis of Rauschenberg's ground-breaking art for several decades. But here the artist takes them further, using the movable shades not as a gimmick, but as a way to reaffirm his commitment to chance, and change, in his own art.

While they lack the overt political content of some of Rauschenberg's earlier works, the "Sling Shots Lit" still demonstrate his flair for social satire and his uncanny ability to seek out surprising, often witty, visual juxtapositions.

Rauschenberg's "Sling Shots" are great fun to manipulate, and a true collector's bargain, since each construction represents several Rauschenbergs for the price of one. The exhibition will continue at 406 Seventh St. NW through April 4. Hours are Tuesday through Saturday, 10:30 a.m. to 5:30 p.m. 'Heat' at Women's Art Center

"Heat" is the title of the uneven but intriguing group show currently at the Washington Women's Art Center. Juried by David Tannous, this exhibition consists of 33 paintings, drawings, sculptures, photographs and prints "representing, inspired by, creating sensations of, or processed from heat."

The subject has generated a broad range of responses. Several of the artists have used "hot" colors, rough textures and unexpected materials to suggest apocalyptic visions of burning buildings and blasted landscapes. Lucy Pirtle's powerful, disclike "Shroud for the Earth" suggests a bomb crater, its irregular surface ironically covered with delicate black chiffon fabric. The relief construction of a ruined city by Lila Snow looks like welded metal but is made from cardboard, sticks and metallic paint; and Elaine Marcus Langerman's aggressively tactile sculpture features a tiny house set within an ominous red-and-black "landscape," which is actually a book, with matchsticks stuck between its pages.

Other artists in this show eschew violence, to depict hot places -- Egypt, or a muggy American city. The "heat" of strong emotion is the subject of Angeline V. Culfogienis' skillful study of her son, his face distorted by anger. A very different tack is taken by Betty Anne MacDonald in "Lust," an extremely funny, bright red intaglio print of a male dog greeting an attractive female dog.

The most exciting works here are two oddly humorous drawings -- the quirky "Screamers" by Jeremy Jelefny, depicting a pair of distressed extraterrestrials with triangular scarlet heads; and E.A. Zando's "You Say You See Snakes?," a lively abstract composition with an assured sense of color and pattern. "Heat" will be on view through March 30 at the WWAC, 420 Seventh St. NW (Lansburgh Building). It is open from 11 a.m. to 5 p.m., Tuesday through Sunday. Tom Dineen at Middendorf

During the 10 years that Washington artist Tom Dineen has been exhibiting his work in area galleries, he has become known for big, powerful charcoal-and-pastel drawings that suggest distorted human figures. Dineen's one-man show of new work at the Middendorf Gallery indicates a significant change of direction -- or, more accurately, directions. While the pictures are still large, they have become less dramatic, more ambiguous and -- in some cases -- more unsettling.

There are two bodies of work here, different in technique, style and mood. The charcoal-and-pastel pieces make no distinction between figure and ground. Instead, the entire surface of the paper is covered with an amorphous mass of swirling shapes, reminiscent of Andre' Masson's Surrealist abstractions. Mostly black, with white and occasional colored accents, these quick-moving forms seem emotionally neutral.

In contrast, Dineen's oil paintings, while extremely vague, are often disturbing. Using small, crude marks and a much lighter palette of flat, chalky grays, blue-green and white, he builds up an indistinct environment from which emerges the barest hint of some unspeakable horror -- in "Decoy," it appears to be a severed animal head (or clenched hand?), dripping blood. Strangely, several other oils have no "figures" at all; their mood is almost lyrical, recalling Monet's "Waterlilies."

While Dineen's work has lost some of its power, it retains its uneasy fascination. Dineen's pictures can be seen at the Middendorf Gallery, 2009 Columbia Rd. NW, 11 a.m. to 6 p.m. Tuesday through Friday and 11 a.m. to 5 p.m. Saturday. The exhibition closes Saturday.