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It all comes down to Zack Snyder’s love for IMAX when shooting Batman v Superman. A native IMAX image has a squarish aspect ratio and uses a lot of the frame. “I had so much fun shooting the IMAX sections of my movie (BvS),” Snyder said to a fan on Vero. “Sort of fell in love with that giant, less rectangular aspect ratio and so that’s why I shot JL 1:85.”

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