Yes, in Christopher Nolan's film Dunkirk, some scenes were indeed shot using Panavision 65mm film cameras, specifically with the IMAX format in mind. Nolan is known for his preference for large format filmmaking and has frequently utilized IMAX cameras in his films.
In the case of Dunkirk, Nolan wanted to capture certain sequences with the highest possible image quality and immersive experience. As a result, he used IMAX 65mm and 65mm Panavision cameras to shoot select portions of the film.
During post-production, the footage shot with the Panavision 65mm cameras was formatted and processed to match the IMAX aspect ratio. This involved resizing and cropping the footage to fit the 1.43:1 aspect ratio of IMAX screens, ensuring that those scenes could be presented in full IMAX aspect ratio.
The combination of IMAX and Panavision 65mm footage allowed Nolan to deliver a visually stunning and immersive experience for Dunkirk, utilizing the advantages of both formats to capture the epic scope and intensity of the story.