It all feels immersive, especially in IMAX. But I’m having a wider screen experience when I watch Dunkirk. I imagine what’s just on the periphery; who else, besides Mr. Dawson, is setting off from England in a little dinghy? Who is up in the air monitoring fuel readings alongside the self-assured RAF Pilot Farrier? Who else, besides the baby-faced private Tommy is ducking the Luftwaffe amidst the dunes of Dunkirk?