I have an odd problem with ambient occlusion. The scene looks great in the preview rendering as well as the actual rendering. As soon as I turn Ambient Occlusion ON in the World settings, the scene gets very bright - both in the preview rendering and the final rendering. I have no clue why that happens.
Here’s a quick comparison of the same scene with and without Ambient Occlusion ON.
I use Cycles as renderer. The scene uses a simple HDRI for lighting. AO settings are nothing special - Factor is at 1 and Distance is at 5mm. Blender version is 2.75 Stable.
Maybe someone can clear this up for me.