Anton Corbijn was talking to Bono about photography one night when U2's lead singer shared these words from Oscar Wilde: ''The mask reveals the man.'' With that quote, Bono unwittingly summed up the approach of music's premier portrait photographer. Corbijn's ability to steal a private moment from folks who thrive in celebrity's masquerade sets him apart from those who do nothing but snap a band leaning against a wall. After spending a lonely childhood in the town of Strijen, in Holland, Corbijn took his first photos of such Dutch bands as Golden Earring (''Radar Love''). ''I always wanted to be in a band,'' says Corbijn, 38. ''Photography was my excuse to be near the stage.'' The excuse evolved into a stint shooting for the British newspaper New Musical Express. Since then, he's worked with the diverse likes of Nirvana (Corbijn directed their ''Heart-Shaped Box'' video), Bon Jovi (he was asked to update their look for the Keep the Faith album), and U2 (he traveled with the band for a year to create the collage cover for 1991's Achtung Baby). ''My sessions are in a bit of disarray,'' says Corbijn. ''Out of that comes the right feeling and a simplicity that allows for a person to reveal so much.'' Some revelations do not come easy. When Bono and Frank Sinatra were making their ''I've Got You Under My Skin'' video, Corbijn managed to pull off only one frame before the Voice barked, ''That's it. You got it, kid? You got it?'' Yes, Frank, he did.