Any discussion about the modern portrait must begin with Annie Leibovitz, the best-known portraitist of our time. In her new book, A Photographer's Life: 1990-2005 (Random House, $75), she focuses not only on modern celebrity -- the very media royalty she helped create throughout her career -- but also on her own life and loved ones. Another famed portraitist, Albert Watson, has recently completed a project on Las Vegas, constructing a series of landscapes, portraits, and still lifes that take as their subjects an array of visually enticing characters that could only come from this particular American city. New York Times photojournalist James Hill contemplates the use of portraiture as historical evidence, as does documentary photographer Lori Grinker. Dutch photographer Hendrik Kerstens turns his daughter Paula into a work of art by re-creating the indelible lighting of master painters. Photographer Mark Laita shows work from his recent book, Created Equal, a clever collection of black-and-white portraits pairing subjects that are, at least on first thought, incongruous. Throughout this portfolio, in fact, the nature of celebrity is redefined. Photographer Todd Eberle, who shoots for magazines like Vanity Fair, offers his take on artist Robert Rauschenberg. Michal Chelbin, a relatively new name in fine-art circles, creates masterly color portraits of little-known circus performers in Ukraine. Portraitist Nigel Parry turns movie stars and other celebrities into icons by seeing past the glitter of fame. Meanwhile, for famed Hollywood photographer Matthew Rolston, the artifice of the portrait is redeemed by its celebration of beauty.