Here is a test setup. There is a Poser Ground. There is a back wall (scaled box). There is a Cylinder. There is one infinite light. No shadows on the light, no AO, no IBL, no IDL.

The light is angled at 45 degrees elevation.

Observe how the bottom of the cylinder is black. This is not technically a shadow, because that surface is pointing away from the light. It is black because it isn't facing the light at all.

I say that is not a shadow because it will stay black no matter what else I do in the scene with other props, and also because shadows are not even turned on.

---

Renderosity forum reply notifications are wonky. If I read a follow-up in a thread, but I don't myself reply, then notifications no longer happen AT ALL on that thread. So if I seem to be ignoring a question, that's why. (Updated September 23, 2019)