Photographs with a wallop, and fish with allure. Cindy Sherman stars in her own staged pictures

IT'S really too bad that the Cindy Sherman exhibition at the Whitney Museum here couldn't have been held during the regular art season, since it's a truly fascinating and challenging show by a younger artist. Surprisingly, it consists entirely of photographs. A few, primarily those of the late 1970s, are small and black and white. Most, however, are huge and brilliantly colored, and dominate the exhibition space with much the same physical impact and pictorial ambiguity we've come to expect of such other artists of her generation as David Salle, Eric Fischl, and Robert Longo.

Right there, however, the similarities end. Unlike these and others of her contemporaries who merely use photography as a source of some of their imagery, she works exclusively within that medium's disciplines and formats. And, even more important, she uses it in new and often startling ways.

As Lisa Phillips, who installed this expanded version of the exhibition (originally shown at the Akron Art Museum in 1983), writes in the accompanying catalog: ``For Sherman the camera is a tool with which to explore the condition of representation and the myth that the photograph is an index of reality. She focuses on the shared public language of the media - TV, the movies, and advertising - turning the camera in on itself to reveal its complicity in reinforcing cultural myths of power and possession. By using herself as a model to replicate other models, she takes control of her own image in active revolt against the roles she is expected to play.''

She accomplishes this by staging and photographing scenarios in which she is the only player, and in which every detail, from everyday attire or period costume to makeup, props, and lighting, is designed and controlled by herself. Her intention, however, is not to create self-portraits, but a series of images suggestive of a wide variety of stereotypes. These range from early B-movie heroines acting out typical scenes to high-fashion models striking outlandish or seductive poses. In every one, Ms. Sherman is shown subtly or dramatically transformed to represent, comment upon, and raise questions about a particular feminine stereotype.

Put that way, her work may not sound like much. And yet, her wit, pictorial imagination, and technical skill are such that almost everything she produces scores effectively, and a few pieces now and then quite literally stop one in one's tracks.

This is especially true of a number of her recent, more overtly theatrical photographs that deal with fantastic, occasionally even grotesque characters drawn from fairy tales, mythology, and horror films. Several of these range in size from six to nine feet and are as richly and exotically colored as anything in the museum or gallery world today. What they are about, however, generally remains open to question. Since all are untitled and identified only by number and year, it is particularly difficult to discover their precise meanings - or whether, in fact, they actually have any.

Considering Sherman's stated fascination with pictorial ambiguity, it is almost certain that they do not, that they are intended to be interpreted according to each viewer's background and inclination. In this she shares the attitude of several of her best-known contemporaries - Salle in particular - for whom the meaning of a picture rests with the viewer, and for whom the primary responsibility of the artist is to provoke inquiry rather than to suggest solutions or to espouse serenity or formal perfection.

Whatever her intentions may be, however, there's no denying that her work packs a powerful wallop, and that it looks stunning on the Whitney's walls. It can be seen there through Oct. 4. `Gone Fishing'

One hardly expects to find a truly delightful gallery show in New York in August. And so, when one appears, it behooves everyone covering the art scene to draw attention to it.

``Gone Fishing,'' an exhibition pertaining to nature, the activity of fishing, and to fish themselves, consists of several dozen excellent oils, watercolors, sculptures, pastels, and drawings by 57 19th- and 20th-century American artists. It occupies two floors at Graham and Graham Modern Galleries and runs the gamut from serious, straightforward pieces by such artists as Winslow Homer and Milton Avery to a number of charming, playful works by Susan Baker, Rodney Alan Greenblatt, and many others.

Fish, of course, lend themselves to fanciful treatment, and a good third of the artists represented here have taken full advantage of that fact. Marsden Hartley presents us with a captivating seahorse; Susan Crile with a charmingly ruffled ``Striped Fish''; Michael Nakoneczny with a witty narrative entitled ``The Revenge of the Banana Fish, J.D. Salinger''; and Mike Love with a mysterious ``Red Fish,'' made of shaved fake fur.

It all adds up to a perfect summer show. The 19th- and early 20th-century section at Graham Galleries, 1014 Madison Avenue, runs through Sept. 19. The modern and contemporary portion at Graham Modern is open through Aug. 28.