In the opening montage of Side by Side, a new documentary directed by Chris Kenneally, co-producer/narrator/interviewer Keanu Reeves explains to several high-profile Hollywood directors what the film's thesis is: "It's a documentary about the science, art and impact of digital cinema...In this conversation, in this kind of intersection of time, it's historic...We've kind of come to this place where... 'Is this the end of film?'"

And for the next 95 minutes, Reeves interviews just under 70 Hollywood directors, cinematographers, editors, actors, producers, lab and computer technicians and others sharing their reasons why they prefer celluloid over digital or vice versa, and how this change has affected, and will continue to affect, the filmmaking process in the coming years.

 "We actually spoke to over 140 people," Reeves says. "Everyone was pretty open about sharing their opinions, their thoughts and experience. And I love speaking about movies, so for me, it was fun. But we did have to make some choices as to who to cut."

The idea for the project began while Kenneally, a post-production supervisor for over a decade, was working on the indie feature Henry's Crime, which starred and was produced by Reeves. "Keanu was a true producer and really worked on every aspect of it," Kenneally recalls. "We were spending a lot of time together in the lab and had a lot of same conversations that ended up in the movie about how digital technology is impacting where film is going. At some point Keanu just said, 'Hey, we should make a documentary about this. You want to direct it?' And I said, 'Of course.'"

They began their quest at CamerImage Plus, the International Cinematography Film Festival in Bydgoszcz, Poland. Among the A-list shooters they spoke to include Vilmos Zigmond, Geoff Boyle, Vittorio Storaro, Michael Ballhaus and Michael Chapman. "These guys are the Da Vincis, Michaelangelos and Picassos of our time," notes Kenneally. "To have the opportunity to ask them questions about movie-making was a dream come true."

If there is a protagonist in Side by Side, that would be cinematographer Anthony Dod Mantle. "As I began researching the project, I would look up what were some of the earliest Dogme films, like The Celebration, and it was Anthony Dod Mantle who shot it," recalls Kenneally. The Dogme 95 movement began in 1995 by a group of Danish filmmakers, most notably Lars Von Trier, as a kind of minimalist response to Hollywood films. The Celebration ("Festen") was directed by Thomas Vinterberg, shot on standard definition video cameras, and took the Jury Prize that year at the Cannes Film Festival. "What was the movie that first moved to 24fps [digital cameras]? Again, it was Anthony Dod Mantle in 28 Days Later," Keneally continues.

Director Danny Boyle tells Reeves in the film how he had seen The Celebration and was blown away by the camera work. So Boyle contacted Dod Mantle and told him, "I feel like I'm not doing the right thing anymore. Can we do something together? Digitally. Which I didn't know exactly what I was saying when I said it. It was like a new word, in a way."

 "And then what was the movie that won the first Oscar for best cinematography that was shot digital? Anthony Dod Mantle again," for Boyle's Slumdog Millionaire, Kenneally says. "So I said, 'I gotta talk to this guy.' He's kind of the through line. His thumbprint is on all these milestones. So it was exciting to find that out, track him down and talk to him. Then we talked to Danny Boyle and Lars Von Trier about him."

In addition to Boyle and Von Trier, Reeves and Kenneally hopped around the globe to speak with other directors, including Steven Soderbergh, James Cameron, George Lucas, David Lynch, Richard Linklater, David Fincher, Martin Scorsese, Lana and Andy Wachowski, Christopher Nolan and Joel Schumacher.

One of the big questions Reaves and Kenneally touch on near the end of their film is whether a conversation about, say, the dynamic range of celluloid versus digital camera even matters to an audience watching motion pictures less and less in theaters and more often on their iPhones and other platforms. "This isn't like going from silent to talkies," Reeves maintains. "It's not like going from black & white to Technicolor; it's actually more subtle than that. Where the documentary leads to is to talk about the philosophical aspects of film, like when Martin Scorsese says that people don't believe the image anymore, but then Jim Cameron says, 'When was it ever real?'

 "What are the new audiences? What are the new screens? How are we experiencing our stories?" Reeves continues. "Not on the big screen. The idea of the image is so mobile now, with so many different mediums. How do we watch our stories now? What can they mean if we're not believing the image? If they're disposable?"

 "I would say what's different in this change—and I don't remember if it was Cameron or Lucas who said it—but now it's anything you can imagine you can create in a real, photo-realistic way," says Kenneally. "You look back on old movies and you could kind of do anything, but people really had to suspend their belief. Yes, that's a model or a fake skeleton running around, but nowadays I can't tell what's been created on a computer and what's been shot. So I think it really frees up the storytelling. Also, the actual workflow on the set and in post-production is really different and really changes the way people think about how they're making a film."

Reeves adds that making Side by Side gave him "a deeper appreciation for things, like when we spoke to Robert Rodriguez and he's like, 'I couldn't have done Sin City [on film].' And I was like, 'Why?' And he gets into what the digital format afforded him--both technical and an appreciation for how he decided to do things. Or David Lynch wanting to have closer intimacy with his actors, which he could get now with digital."

It should be noted that documentary films are not mentioned at all in the film. "We didn't discuss documentaries pretty much because it already happened, it's not happening right now," Kenneally explains. "Documentaries went digital long before Hollywood has with narrative films. Narrative films are sort of the last vestige where film is really hanging on, so it didn't seem like there was enough of a struggle or conflict going on [in documentary] and we'd be talking about something that's already changed."

Certainly one of the entertaining aspects of watching Side by Side is seeing Reeves sit on the other side of the interview table. When asked what advice he would offer to interviewers, he says with a chuckle, " 1) Listen; 2) It's not about you, it's about them; and 3) Be prepared. Those are my three rules of interviewing."

But there is also a downside to this transition from celluloid to digital, Kenneally notes. "The thing I feel most nostalgic or even sad about is the actual craftsmanship. Like Vilmos Zigmond and Vittorio Storaro--these guys know exactly what is going to come up on this piece of film by how they set their lights, the type of stock they use, and how they set the aperture and film speed. And they get these beautiful things. And that took decades of people working and crafting and learning, and really honing a skill. And now you just turn on a Canon 5D camera or even an iPhone and get a pretty good thing, but you're missing the craftsmanship—that real connection with the material, that knowledge of how it's coming together."

 "What have we lost?" Reeves adds. "That is something that might also be philosophical. But the experiential aspect of dealing with film, the materiality of it. How we see it—the physical light through film to represent an image--having that lost, what does that mean? Certainly, in a sea change of this technology a lot of people have lost their jobs, so there's an industrial turnover that's occurred. Again, what have we lost? The experience of making a film and how it looks—what is that?

 "I kind of end up where Michael Ballhaus ended up when he just speaks about anytime you do something with passion and your heart, it's really inspiring," Reeves continues. "And after going through everything and listening to James Cameron's idea of what could be possible in the future. That's one thing. Then there are also the naysayers who were like, 'Well yes, this may be, but right now we're not technically there yet for the look of film.' But it is still this great vista opening up. Especially with the democratization, the technical tools being made available, etc., etc. It's an exciting time."

 "It was so inspiring to myself, Keanu and our DP and producer," Kenneally says. "We were a very small crew and to be able to sit and listen to David Fincher and David Lynch telling us it's not hard to make a movie and just go out and do it. Or Richard Linklater saying the tools are there now, there's no excuse. Seeing these guys, it was just inspiring and makes you want to go out and make movies. And just hearing them talk about the technical things, just kind of demystified some things.

 "I hope when people watch the documentary," Kenneally continues, "they get an understanding of what really goes in creating an image and how much these people--even if they argue different sides of it—how much they truly care about putting a quality image into the movie. And I hope after watching the film, you'll have a better appreciation, in general, for movie-making—whether it's film or digital. And I hope it excites people to go out and watch those movies. I know sometimes when we were finishing editing a sequence—like Collateral or Lawrence of Arabia -- we'd be like 'Hey, that's exciting. I want to go watch that movie again.' So I hope that others will get that feeling when they watch our film."

 "Making the film," Reeves notes, "was a real adventure."

Side by Side opens in select theaters August 20 through Tribeca Film, and on VOD August 22.

Ron Deutsch recently co-wrote the documentary OK, Buckaroos!, on the life of singer Jerry Jeff Walker. Interviews he did with shlockmeisters Herschell Gordon Lewis and David Friedman in 1980 were released for the first time as extras on the American Grindhouse DVD last July. He also teaches cooking classes in Austin, Texas, and writes for The Criterion Collection as Chef du Cinema, pairing films and food.