Zack Snyder explains why he shot Justice League film in a more different aspect ratio from what he used in Batman v. Superman: Dawn of Justice. Batman v. Superman was only involved some part being shot with IMAX cameras and was captured in the standard 2.39:1 aspect ratio. Snyder responded to a fan recently that many scenes in the Justice League film was shot with IMAX camera, which some BvS was shot in 1.44:1, then converted to 1.9:1 for IMAX’s digital formats:
“I had so much fun shooting the IMAX sections of my movie (BvS). Sort of fell in love with that giant, less rectangular aspect ratio and so that’s why I shot JL 1:85.”
The Justice League film 1.85:1 aspect ratio means IMAX theaters will present a definitive version of the film as shown by Christopher Nolan with Dunkirk film earlier on.