Sympathetic but unsparing photographs;Silver Lining: Photographs by Anne Noggle, text by Janice Zita Grover. Albuquerque: University of New Mexico Press. 193 pp. $60.

IN a speech delivered to the graduating class of the Portland (Maine) School of Art in 1983, Anne Noggle said: ''To look straight into a face and find the pulse of what it is to be human, that is what fuels me, that is the sum of my mind and my longing.''

And photographing those very human faces - primarily those of old people - is just what Noggle has been doing for the last 15 or so years; the evidence of her sympathetic but unsparing gaze fills the pages of ''Silver Lining.''

Noggle's mother, Agnes, appears in many of the 80 black-and-white photographs in this monograph, starting as a healthy-looking woman in her 70s but in subsequent images visibly aging, appearing more frail, undergoing what Jung called ''the contraction of life.''

Noggle also photographs herself (clothed and not) and even records - surprisingly, she admits, given her interest in photographing the dignity of the old - her own facelift in 1975.

''Silver Lining'' refers to a series of photographs of married couples Noggle did in the late 1970s. Only five photographs from the series appear, not enough work from which to generalize, although Noggle feels the series is about ''a double-edged idea that life together is and isn't a bowl of cherries.''

Noggle's background is unusual. By the time she was a senior in high school she had a pilot's license and served as a flight instructor in the Women's Air Force during World War II. After the war, recounts Janice Zita Grover in the consistently thoughtful essay that accompanies the photographs, ''Noggle taught flying, joined an aerial circus doing stunt flying, and later crop-dusted throughout the Southwest.''

In 1959, the 38-year-old Noggle entered the University of New Mexico, connected with photography, and knew then, she says, ''what I was going to do for the rest of my life.''

In the 1970s she was the acting photographic curator at the Museum of Fine Arts in Santa Fe, photographing on her own time or when time was created by a National Endowment for the Arts photographer's grant. She won such a grant in 1975, another in 1978, and a Guggenheim Fellowship in 1982.

Most of Noggle's photographs are not easy to look at, for while she clearly admires the aged, she will not trivialize their problems by producing overly sentimental images. Simply, she understands the difference between sentiment and sentimentality.

''I hope,'' says Noggle, ''that all of my images have or hold in some sense the heroics of confronting life. . . . I'm trying to humanize the middle-aged and older, to find a new perspective that . . . (lets) them be a viable part of society. I cannot view life as a tragedy alone.''

James Kaufmann reviews books regularly for the Monitor.