Hello everybody,
the DOF is totally done in Corona, I don't really know why the pentagons are rotate differently.
Yes the setting for GI/AA was something like 8 or less, I don't have the scene here with me.
About the render time I resume the render many time so I can't tell you, for the last pass I did set 1000 pass as maximum limit.
The render is not clean yet so probably need more hours to achieve a better result.
The lighting is made by a HDRI in the environment slot, done by myself in Photoshop, a very simple HDRI.
there are some invisible bluish sphere floating on top of the crystals. (light material)
The displace is Max geometry displace mapped with different noise map mixed together.
Very very simple and basic scene and a little of contrast in Photoshop.