Andy Warhol may be best known for brightly colored silk-screens and clever riffs on pop culture, but an exhibition at the Museum of Modern Art focuses on his silent and often challenging films.

The show, "Andy Warhol: Motion Pictures," which opens on December 19 on runs until March, consists of 14 "screen tests" -- short, silent, black and white portraits of the artist's friends -- as well as some of his longer works.

The "screen tests" in the show were selected from nearly 500 small films made from 1964 to 1966. Taken together as a whole they represent a who's who of New York's downtown art scene of that period.

"One of the things that makes these 'screen tests' so interesting is not only Warhol's interest in celebrity but more importantly I think his interest in rethinking the whole idea of portraiture in the 1960's," said Glenn Lowry, director of the Museum of Modern Art.

Musician Lou Reed, writer Susan Sontag, socialite Edie Sedgwick, poet Allen Ginsberg, artist Dennis Hopper and others are featured in the films.

The projections glow in sharp black and white, Reed staring intently at the camera and Allen Ginsberg's dark beard and mane of hair swallowed in the shadow of the frame.

Museum curators also included some of Warhol's more ponderous, complex films, such as "Sleep," "Eat" and "Empire," some of which are only projected at scheduled screenings.

In the 86-minute excerpt of the five-hour plus film "Sleep," in which Warhol filmed the poet John Giorno, the artist seems to play with the viewer by at times including utterly still moments at the limits of the moving image and the photograph.

Viewers can also see the eight-hour silent opus "Empire" about the Manhattan skyscraper, or "Kiss," featuring 13 couples petting and passionately embracing.