I was thinking about this when I was playing around with a standard lighting set up for a project that I’m working on in Blender. One example is how, in the real world, you rarely get truly black shadows beneath objects.

I quite often see 3D work that would look that little bit more realistic if this simple fact had been taken into account and steps taken to fix it.

In my standard scene setup (top-right) I have a sphere primitive placed on my studio object (just a smoothly curved floor to wall object). It’s lit by a lamp and a spotlight. The underside of the sphere is unnaturally dark.

By adding an area light beneath it at a low energy setting (bottom-right), the darkness can easily be corrected to make the scene look and feel more realistic.