Leibovitz took double photos of the showgirls--shots that ended up in the book and established the method she used to piece together this body of 200 portraits.

Asked by the audience how she decided whom to photograph, Leibovitz said "it all came down to reading The New York Times." She said she tracked down people she read about in the newspaper and sought to photograph them.

Aside from music stars, actresses and politicians such as Cameron Diaz, Elizabeth Taylor and Hilary Clinton, the book includes images of coal miners, rappers, AIDS activists and prostitutes.

According to the photographer, these portraits were "stronger" than her magazine shots--mostly because she was freed from the need to flatter her subjects and sell magazines.

And in some cases, Leibovitz said, her ideas conflicted with the model's. She cited the example of Yoko Ono, who Leibovitz thought could take a "strong" head shot, under hard light, with enlarged details. To Leibovitz's surprise, Ono was dissatisfied with the final product and had to be appeased with a softer portrait.

The book includes a wide variety of pictures, from nature to studio shots and from black-and-white to color.

Some members of the audience questioned why so many of the book's models are shown being serious.