It’s not often that the paintings of an Italian Renaissance master arrive in a New York museum unadorned by the aura of fame and towering talent, but so it is with Giovanni Battista Moroni. The art of this 16th-century painter who excelled at remarkably naturalistic portraits is having its first American survey at the Frick Collection in “Moroni: The Riches of Renaissance Portraiture.” Partly because Moroni’s reputation does not much precede him in this country, the show’s 23 portraits have a stunning freshness and clarity. We have the sense of seeing for ourselves — and there is much to look at.

Part of this freshness is inherent: Moroni’s paintings themselves are unencumbered. He scrutinized reality with a new directness and tried to record what he saw. His relatively low-key style adds to his portraits’ transparency, the feeling that we are looking at real people as they existed — unidealized, meticulously observed and psychologically present, especially in their direct appraising gazes.

The grand old man thought to be Gabriele Albani, in a portrait that Moroni painted around 1572-73, wears a lavish lynx-lined robe, but he also has a prominent bump in the middle of his forehead — although its suggestion of a third eye is not without a certain grandeur. Even more strikingly honest is the wrinkled face and goiter of Lucrezia Agliardi Vertova, who holds a prayer book in hands that the catalog suggests were painted from a younger model once the painting’s subject was no longer available. That Moroni did not add wrinkles here is testament that he could not paint what was not in front of him.