Dominating the atrium of the Market Arcade Building is Tatana Kellner's restrained and reverential "Requiem for September 11th," a memorial to the victims of Sept. 11, 2001. As a lead-in to "Assemblage and Ritual" - Kellner's massive midcareer retrospective installed in all five of CEPA's galleries - it sets a high standard of formal clarity and conceptual straightforwardness.

The Sept. 11 tragedies, still so painfully close, have barely begun to take on a discernible historical reality. Accounts of the events still hold their immediacy. Those who narrate such horrific happenings, without thinking about it, forestall the inevitable: These things, too, will settle into history. As that happens, the anguish in living memory will slowly slip into the protective arms of collective memory.

Through her photographic art, Kellner attempts to arrest, if not reverse, this process. She wants to restore to tragic history a renewed sense of original pain and loss. It's true that to some extent all art attempts to revitalize past experience. But Kellner does it pointedly and specifically, often using the most formidable subject of the 20th century - the Holocaust.

The daughter of Holocaust survivors, Kellner has many personal connections with the subject. She was born in Prague, Czechoslovakia, and arrived in this country with some of her family in 1969. By 1978 and into the early '80s, she was doing a form of family portraiture - shots of her parents, Eva and Eugene, in their home and of their environment. In 1992 she bravely took on their separate experiences directly in two hand-made books that movingly tell their stories in their own words.

Very early, it seems, Kellner established the dark, meditative mood that was to pervade much of the later work. In the many and complex pieces - done from 1990 to the present - Kellner continues to use personal images and stories. Now, however, she joins them to borrowed historical images and modified views of such things as funerary statuary and grim architectural fragments, some from the concentration camps where her parents were imprisoned.

These are sometimes big, irregular pieces in which highly manipulated images jam and overlay one another in controlled compositional violence. Other times they assume a conventional religious triptych form, as in the melancholy "Czech Woods - Faith Remembered" (1991) with its juxtaposed angels and cryptlike chambers.

Typically in these works various symbolic representations of death and destruction are used for both their expressive potential and formal control. Flames, for example, flicker through some compositions - most poignantly in "Ancestor Burning, Not Yet Consumed," where it is impossible to separate depicted flames within images from those that lick around the edges like burning frames.

Kellner's technical arsenal is formidable. In addition to the standard overlaying, multiple exposing and masking, she abuses her negatives and prints by scratching and drawing and painting on them. In her hands, developer and fixer become close to a painting medium. (She originally studied painting.)

This technical wizardry is not always an asset. Some of the more elaborate of the pieces - which outside the installations form the bulk of the work in the show - can be technically overburdened. Photo-assemblage has a demanding, perhaps closed-off history, thanks to wildly prolific artists like Robert Rauschenberg. Kellner's visual manipulations depend on a now-conventional tactic of sampling and juxtaposition, which are altered by various formal means (superimposition of images, drawing/painting interventions).

These conventions aren't necessarily fatal to her assembled photographs. Through her affecting broken narrative and a powerful symbolic vocabulary, Kellner does reach powerful expressive heights. It's just that she does this with less falderal in the installations.

Though visually a complicated installation, "While You Were Sleeping" has a touching simplicity that approaches naivete.

Images of sleeping women - here only gently manipulated - are printed on pillows illuminated from within and suspended like clouds throughout the gallery space. The sky reference is reinforced by cloud shapes on the back side of the pillows. With this child's room imagery, these mature women (friends and acquaintances of the artist) are, in sleep, carried back to childhood and to the beginning of personal history.

Some of these sleeping heads are set against stones or decorative reeds like those of a cemetery. Here the line between life and death blurs. What at first seem merely wistful emotions are distantly tinged with tragedy.

In this installation, and in a few of the less elaborated pieces ("Transformations" and the burdock leaf images), Kellner may equal her achievement in the "Requiem." It is in these works that the artist finds an equilibrium in which distinctly personal feelings blend unobtrusively with the larger shared emotions of society.•