I re-watched the Wizard. My brief stint as a reviewer of cinematography is over.

They did manipulate the apparent depth of the back drop. But not everywhere. The Scarecrow's field, the mountain vista from the witch's castle, and a little bit in the field of poppies. (Po-o-o-o-o-pieeeessss.) It's mostly pretty subtle. And it still has the Truman Show effect. There's only so much they can do with depth before it hurts your brain. So they were pretty modest in how far they pushed the scenery around. The craziness of modern computer animated 3D isn't present.

The film generally has a shallow depth of field. My conjecture is that this helps mask some of the limitations of a sound stage. Anything very close or very far away from the camera is soft due to focal blur (being slightly out of focus). In the synthetic 3D, they did a nice job of maintaining consistency between synthetic depth and the depth as apparent from camera blur.