"DIGITAL TECHNOLOGY is evolving to a point that it may very well replace film as the primary means of creating and sharing motion pictures," Keanu Reeves narrates at the beginning of Side by Side, speaking over quick cuts from Sin City, The Curious Case of Benjamin Button, Slumdog Millionaire, and Avatar—all films shot digitally. Considering the state of cinematography and distribution—with digital cameras and projectors having all but muscled out traditional 35mm—Reeves probably should've just said "has replaced" instead of "may very well replace." Still, Side by Side shows a pretty great cross-section of the film industry as it grapples with one of the biggest transitions in its history.

Side by Side's useful as a history lesson too, tracking the rise of digital cameras from consumer-level camcorders to Michael Mann's stunning vision of Los Angeles in Collateral, making side-trips to highlight innovations from the Dogme 95 movement and the revolutionary use of digital color timing in O Brother, Where Art Thou? But more interestingly, it digs into human reactions to the shift, with an impressive array of talking heads—from directors to editors to special effects supervisors—weighing in on how digital filmmaking has changed the way movies are made, watched, and sold. There are the usual giddy proponents of digital (James Cameron, George Lucas, Danny Boyle, Steven Soderbergh, Robert Rodriguez, David Fincher), some unexpected proponents (Martin Scorsese), too few young, independent voices (Lena Dunham), and a couple of filmmakers who steadfastly oppose digital, personified here largely by an exceedingly grumpy Christopher Nolan. (That's too bad, considering 35mm still has a swath of talented devotees who don't show up here, like Paul Thomas Anderson, Quentin Tarantino, Rian Johnson, Wes Anderson, and Steven Spielberg.)

But for all the talking—and boasting, and hand-wringing—most of the fun of Side by Side comes down to simply hearing accomplished filmmakers geek out. Like when Reeves asks David Lynch if he's truly done with 35mm: "Don't hold me to it, Keanu," Lynch says, in a line I want to be my new ringtone, "but I think I am."