Anyway, thought I might post it for some feedback to see if you think I am on the right track.
The DoF is still a bit noisy as I am rendering with Reality/Lux.
I don't like the position of the Sun in this one or maybe its the camera.
I debated about the sun position for a while, I may still change it. The camera angle is staying though, as I want a human level camera to emphasize the size of the ATAT. I may add other elements to the scene as I go along as well to flesh out the environment a bit.
Your render is off to a promising start, however I think the blur intensity is too much. It makes it look more like a miniature. Is there a way to dial it back bit to make it more subtle?
The other minor quibble would be the bear's shader, it looks flat and painted on. I don't have experience with Reality, is this look caused because the render calculations aren't complete? Will subsequent passes or whatever fix this issue? Whatever the issue, it's a DOF challenge and not a shader challenge, so if it's a PITA to fix or change, I'd concentrate on the challenge first and foremost. Good luck!