@pascal
I designed the original standard illumination object in 2006 (initially for Maxwell). The idea has been loosely copied ever since by various communities over the years.
There is no reason Rhino can’t have the original. (and I have been with Rhino longer)
There is a download for it here without the Maxwell logo on it (if anyone at McNeel wants it) → Here
Originally it came with a tech sheet, but a lot of it refers to Maxwell specific instructions.
Also the tech sheet refers to a version 1.1 where the core sphere had emitter elements, but they were rarely used. This is the simple tried and true incarnation of this object (originally nicknamed SIMball-Standard Illumination of Materials Ball) INSTRUCTIONS-StndMatScene.pdf (1.5 MB)
Found a texture mapping issue on the base (Rhino file) and corrected it.
(Maxwell users were using MXS files so they were not affected) StandardIlluminationBall - (cleaned).3dm (1.0 MB)