Hi there,
Hmmm, that still renders a flat grey colour as almost totally blown out white.
I think what we should do is to render a calibration card (pure rgb texture based reference image) on to the 'unit' isometric square, with a range of spheres with pure rgb texture based imagery (solid colours from 0 > 255 rgb) as calibration images.
Right now it seems that many are using 'unreal' values for lighting and so we are using unrealistically low rgb textures to make things look right.
I am not very familiar with Blender, but the best we could do is render these images out so that those using other apps can get a faithful setup to match it.
I will rebuild a Max2010 template with sensible observations of real life made against my virtual version (I am just collecting the required chrome ball, 18% grey and flat white balls to make calibrated photos of real life lighting so we can sim it better)
It would be cool if we could do the same in Blender and get a unified setup we can calibrate across renderers easily
Dave