If you’ve ever seen a Christopher Nolan film in theaters, particularly on a gigantic IMAX screen, you will never fail to be wowed by the stunning visuals that the director brings to the table. His movies are uniformly gorgeous, which is credited to his work with ace cinematographers like Hoyte van Hoytema and, previously, Wally Pfister. His latest film, Oppenheimer, is no exception to this trend. That said, there is one complaint that seems to exist among audiences, no matter how good the movie is: they can’t always hear the dialogue.

This issue was particularly notable in Nolan’s last film, Tenet, where the sound mix seemed to minimize the audience’s ability to hear the dialogue. The film also featured a number of scenes that saw the film’s stars, John David Washington and Robert Pattinson, wearing gas masks that caused their audio to be muffled, which only further exasperated the auditory issues. Speaking with Insider, Nolan admitted that he is aware of the complaints, and explained that the issue comes from a combination of reasons—including his preference for filming on IMAX cameras.

These massive cameras are not soundproofed in the same way that standard film cameras are, which can cause the noise generated by the motors inside the camera to compromise the audio. This is just one of the challenges that the film’s cinematographer spoke with Collider about recently, though it is a reasonable sacrifice when the trade-off is the stunning imagery that can only come from working with IMAX. While speaking with Steve Weintraub, van Hoytema said, “If we would be able to fix the sound in an IMAX camera, it would be fantastic. Now, it’s almost to solve that sound problem is like defying physics. It’s not just asking, ‘IMAX, can you make this thing more quiet?'”

ADR Could Help, But Nolan Prefers to Avoid It

While speaking with Insider, Nolan disclosed that significant advancements to improve this flaw have been made in recent years, which now allows for more intimate shots and close-ups in movies that previously would not have been possible. Nolan explained:

“There are certain mechanical improvements. And actually, IMAX is building new cameras right now which are going to be even quieter. But the real breakthrough is in software technology that allows you to filter out the camera noise. That has improved massively in the 15 or so years that I’ve been using these cameras. Which opens up for you to do more intimate scenes that you would not have been able to do in the past.”

Despite the promising breakthroughs in software, which would have helped a lot in figuring out what Bane was saying half the time in The Dark Knight Rises, Nolan admitted that the quality of the dialogue could be improved even more by ADR, or automated dialogue replacement, where the cast records their lines in a studio environment to provide greater clarity. Just one issue—Nolan doesn’t like to do this. Instead, he prefers to use the dialogue that the actor provides on the day, believing that it adds more authenticity to their performance. In the interview, Nolan went on to reveal, “I like to use the performance that was given in the moment rather than the actor revoice it later. Which is an artistic choice that some people disagree with, and that’s their right.” While ADR can be beneficial in certain situations, it’s hard to argue with Nolan when his films always have a distinctly authentic tone to them because of how he chooses to capture his actors’ performances.

Oppenheimer is currently playing in theaters, where you can judge the audio mix for yourself. Catch our informative interview with Hoyte van Hoytema down below: