I am shooting a short horror movie for a film festival and I have an idea which I don't really know how to imply. I don't think, that this thing is unique and never been used by anyone else, but I want to do it anyway. So basically, there is a man lying on the ground, in the forest by the river. He opens his eyes and the camera sets a shot in which you see his face, looking into the lens, and clouds behind him running fast. This means his distorted perception of time. Then gets up, he stares into the clouds, still running by fastly. This shot has to be from his back and taking him full-length. He is just standing and in another shot moving, but slower than the clouds, normaly. Not speeded, not slowed. I hope you get what I'm trying to say here.
I was wondering to do the two-shot takes. The upper shot would be clouds, fast-forwarded, the lower - man, at normal speed or even slowed a bit for that creepier effect. But I dismissed this solution, because when filming outdoor, the place of the sun will change, meaning the light position in both of the takes being different. Wouldn't look good. Any ideas how to do this right?