Why wasn't a giant hole created when Kylo Ren fired upon the vision of Luke Skywalker?
Actually, there is a hole behind Luke, but barely visible, and maybe a bit too small given the massive rain of fire that poured upon him. And the hole's immediate surroundings are undisturbed, which can't be right given the cloud of debris created as the walkers fire.
The first shot:
I said increase firepower!
Just a tiny scar on the ground?
Plus, there's a bit of a continuity error anyway, because the massive damage from the siege cannon is also absent during the fight between Kylo and Luke. I guess the SFX team missed something on that scene, which would also explain why we don't have a big hole behind Luke.