Nicholas Nixon's disturbing photographs are carefully tucked away in the back room at Fraenkel Gallery. Nixon is compelled by what people are like in extremes. This pitiless and profoundly humane series of photo capturing people at the end of life old people in nursing homes, couples dying of AIDS continues his investigation. Using his 8-by-10 format camera, his eye refuses to look away from sights that make casual gallery viewers turn and bolt from the room. A trio of images of an ailing man in his 30s or 40s show his shaved head, cleft by surgery, the arc of his ear echoing the arc of bony skull. His eyelashes, whiskers, and body hairs are fine textures on the topography of his freckled skin. An elderly woman raises an eloquent bony hand, palm up, with creases like Roman numerals. Babies with tubes in their noses and bright eyes are surrounded by loving and desperate parents. A tender couple entwined calls up images of biblical Jacob wrestling with the angel: She is a cancer patient, her head bald, the stigmata of surgery on her chest, her eyes dark pools; he is holding on to what is left of her. Nixon seems to ask "Who is there? What is left when we are close to death?" He often finds what he is seeking in the eyes of his sitters fear, yearning, or a flicker of defiance. L.F.