Christopher Nolan’s WWII movie hits theaters later this month and a new featurette shows just how creative the director and his cinematographer had to be when it came to using the IMAX cameras.

“Dunkirk” follows World War II’s famous Dunkirk evacuation mission from three different points-of-view and when it finally comes to theaters it will be projected on 70mm film in 125 theaters across the country, the largest such release in 25 years.

Director Christopher Nolan is no stranger when it comes to using the IMAX cameras having filmed most of Interstellar and The Dark Knight Rises in the larger format. When it came to making “Dunkirk” Nolan used handheld IMAX cameras which were difficult to fit onto planes and other cramped scenes for the movie.

Nolan was only able to film about 70% of the movie using the IMAX cameras. The reason why Nolan didn’t film the movie entirely in IMAX is that the director still uses the IMAX film cameras, which are incredibly loud. For particular scenes involving a lot of dialogue they had to use quieter 65mm cameras instead.

Early reactions to the movie have given it high praise for its intensity. Check out the featurette below as they explain how they made the IMAX cameras work for such a movie and the inventing they had to do to make everything work.

Dunkirk opens July 21st.

Dunkirk Cast: Fionn Whitehead, Tom Glynn-Carney, Jack Lowden, Harry Styles, Aneurin Barnard, James D’Arcy and Barry Keoghan, Kenneth Branagh, Cillian Murphy, Mark Rylance, and Tom Hardy

Categories: Movies

Tags: Christopher Nolan, Cillian Murphy, Dunkirk, featurette, IMAX, Movies, Tom Hardy, Video