Top writers and artists -- in the camera's eye; The Writer's Image, by Jill Krementz. Boston: David R. Godine. $25.; Artists: Portraits From Four Decades, by Arnold Newman. Boston: New York Graphic Society. $49.95.

These two books eloquently contradict Shakespeare's observation that "there's no art to find the mind's construction in the face." Not only have the two photographers here perfected a method, the descriptive portrait, but in the process they've achieved an art form.

Nothing, it would seem, would be more challenging than trying to photograph a writer. One can't imagine a more elaborate exercise in note-taking; a one-upmanship of perception by both sides. Uncomfortable that his role has been usurped, that he must bem observed rather than observe, the writer conjures yet another literary conceit. His face becomes a blurb written by someone else. It's only point of fascination is how he imagines himself being seen.

"The Writer's Image," a collection of over a hundred portraits of famous writers, is the exception to prove the rule. Photojournalist Jill Krementz, herself the author of several books, has succeeded in the most difficult of tasks: She has found the face behind the one most comfortable when creating or temporarily wearing others.

"The Writer's Image" is a literary record, highly personal in feel, of great warmth and candor. It never intrudes or probes unnecessarily. Rather, each portrait is, in Miss Krementz's words, "a collaboration," a visual trust between two creative people. The result is a series of images of rare exuberance, wit, and intelligence.

An outer as well as an inner vitality animates these portraits. There's a jump-roping John Updike, a Zorba-dancing William Saroyan, a toe-tapping Truman Capote. Not only has Miss Krementz caught her subjects in daily life; her portraits mirror deeper qualities of that life. There's Bruno Bettelheim and his wife locked in loving, childlike embrace. It is a joyous comment on his own work. There's the train-bound Paul Theroux, the cultural outsider, the willing exile.

These portraits are also explicit comments or descriptions of a writer's style. A photo of E. B. White in his Maine study, for example, is elegantly austere. Like White's prose, it's characterized by a stunning simplicity. Similarly, a series of portraits of Miss Krementz's husband, Kurt Vonnegut, are both comic and contemplative just like his novels.

"The Writer's Image" is a small miracle in an age blighted by photographic prurience, of People magazine, of gossip for illiterates. This is a book of balanced respect and quiet dignity. A kind of visual parallel text to each writer's work and life. After you buy their books, buy this one.

Arnold Newman's portraits of painters and sculptors are markedly different in feel from Miss Krementz's literary ones. They are portraits of great formal elegance; chilly icons of creativity. One stands back and studies them much as one might contemplate a painting by his subjects.

A visual compendium spanning four decades of portraiture, "Artists" reminds us what Newman does so well. He instinctively finds the setting or angle that suggests his subject's works and then places the subject himself within the setting. Sculptor Alexander Calder, for example, sits under his own mobile so his head becomes a part of it.

"Artists" not only offers us almost practically every great art figure of the past 40 years, it also offers a striking glimpse of Newman's talent. One cannot contemplate the first without being made aware of the second.