It's been over a year since I last had some fun with Octane, but recently I found a little time to have another go.
The goal this time was a series of images designed to push realism in lighting, while trying to achieve a 'photographed' look.
The plan was to use a single setup, which was lit several different ways.
I'm pretty happy with the results

Some specs:
1x skull object (purchased from TurboSquid) @ 130k tri's.
Skull is instanced approx 10,000 times.
Lighting uses physical sun and sky mainly, although one render uses geo lights.
Renders created with Octane for Maya (love it!); PMC kernel, post bloom/glow (subtle).
Grading and post tweaks handled in Nuke (tweaks were pretty minor, but essential in pushing the realism that extra bit more).
Atmospherics created with a subsurface medium (slowed renders down quite a bit).
Render times... Between 5-15hours (GTX670).
--