Room as camera obscura using Octane Render

This is mostly 'proof-of-concept' / 'technology demo' image, rather than completed artwork But it can be interesting for someone because of:
   Demonstration of possibilities of unbiased render engine - the small hole in wall works exactly as it should IRL, projecting environment light to room's interior, while turning it upside down.
   Nice artistic effect of room turned into 'camera obscura', can be featured in various scenes
   It's the good challenge for other (unbiased) render engines.. let's hope it's also possible to render in iRay or some other ones

Unfortunately, the render process requires just incredible amount of computing power and the first appropriate image appears only after noticeable amount of time. So... to render full scene (with characters, for example) in appropriate time and low noise, you will need a rig with several GTX Titan at least

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 More links on theme:

Artistic works
thecreativediary.blogspot.com/…

Detailed (real-world) tutorial with explanations and tips
content.photojojo.com/diy/diy-…

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 Tech details:
Octane Render 2.24.2, 28k spp in PMC mode
Room was modeled in Blender (having size of 3x3x4.5 meters with 50mm round hole in one wall), OBJ file in attachment
Other props are from Poser (The photo camera with tripod >> www.renderosity.com/mod/freest… )
Environment HDRI from HDRLabs >> www.hdrlabs.com/