I've been wondering this because no matter how good renders of V3, V4 etc made with Poser or DAZ are, they still look like  DOLLS , they don't look real. I don't know what it is but they look like plastic, not alive.

But when i see professional pictures of humans made in 3DMAX/MAYA, they look extremely real. Almost like real people.

The Lux Renderer is changing things little by little but  The default Poser and DAZ renders  even with great lighting don't give me the impression of human characters being realistic and having real skin.