Bradley Cooper played a major role in the editing process of Joker. Cooper and director Todd Phillips go back to the Hangover days and the actor serves as a producer on the Academy Award nominated comic book movie. Joaquin Phoenix stars as Arthur Fleck in the big screen character study on one of the most iconic villains of all time. With that being said, the movie is ambiguous and Fleck could really be just about anyone, which is more than likely why the movie works on so many different levels.

Even though Todd Phillips shared quite a bit with fans on social media prior to Joker's release, he never really got into specifics. The same can be said for Joaquin Phoenix, who is still reluctant to reveal too much. As it turns out, the production was quite secretive, even though it took place in public. Joker editor Jeff Groth had this to say about the secretive project and who was allowed to check out updates.

"We kept this one pretty close to us. We screened it more personally for people and filmmakers. Bradley Cooper definitely came in a couple of times. He was a producer on the movie, but he definitely watched the movie many times and sat with us. We could call him if we got stuck with something and be like, 'Hey, can you come over and take a look at things?'"

Bradley Cooper makes sense since he is a friend of Todd Phillips and a producer on Joker. But, he ended up helping out a lot more than anyone expected, at least according to Jeff Groth, who was just nominated for an Academy Award. Groth says that Cooper has quite the eye for detail. He explains.

"He doesn't miss a thing (laughs). He would watch stuff and he would pick out even some of the smallest things and what are some of the things that he can be picked out for us to address. He was definitely a huge help. I think he got a lot more experience in editing than most people would realize."

In addition to Bradley Cooper coming in to lend a helping hand on Joker, Joaquin Phoenix was also in the editing room quite a bit, says Jeff Groth. Phoenix works in ways that many people feel is unorthodox and being a part of the editing process falls in line with that. Groth isn't used to actors hanging around during editing. He had this to say.

"I think probably he was in the edit room more than any other actor that I've worked with... What was interesting to have him come in is that he would always be looking to get the feeling from what was on screen to mimic the feeling that he had on the day [he shot it]. It was a really interesting perspective to have in the room. Of course, you're putting together what you're putting together, but then to have somebody saying like, 'I lived that moment and here's what I'm feeling.' It's another interesting perspective, so kudos to Todd for having him come in."

Joker was very much a team effort that took full advantage of the time that they had. There were no reshoots. Instead, the rewrites and additional takes were all taken care of during principal photography, which added to the urgency in the final cut. The movie made over $1 billion at the box office and now has eleven Academy Award nominations. It looks like they all did something right. The interview with Jeff Groth was originally conducted by Collider.