An easy way to render only the ground shadows

[Speedster]

I don't think this information is accurate, although the results may appear similar;  interior mode doesn't emulate an enclosed environment without the geometry to contain the light.

Yep.  As I've mentioned, I'm just not sure about an enclosed environment yet.  I was intrigued when I was setting up a product shot using all physical (IES) lights.  I noticed that the two primary key lights seemed to obey the "Inverse Square Law" that we used to use in real photography rigs, in which one key light "dims" in intensity by a factor of two when moved twice the distance from the target than the other key.

I tested  a closed "box" with flat black material on the inside, and I don't see a difference between an enclosed environment and an open environment with the HDR set at zero. 

Lets assume an enclosed box one mile (1.6 km) on each side.  This would have a negligible effect on reflections for say a small product on a table. 

I understand the logic, but don't see the result.  Regardless, I'm getting way better renderings in Interior Mode at HDR=zero.

Bill G

[Paul Garcia]

Are you rendering in "Interior Mode"?  If so, try reducing any HDR Environment to zero, and use Maximum Time.  I think it emulates an enclosed environment, and may harden the shadow edges even more.
Bill G

Hey Bill....going to play around with your settings just to see what happens.

Question, how do you turn HDR environment to zero?

thanks

edit: just looked this up and saw its turning the brightness down to zero