How to make a sharp shadow? In the picture the sun makes a diffuse shadow on the interior wall of the poolhouse. I want this to be a sharp shadow (as would be the case in real life, with a full sun). Don't know if and how I have to change the wall material and/or the lighting (or whatever).

(the material of the wall is shown on the right panel, as "concrete")
A sun lamp with size 0 will give you a very sharp shadow:



As you increase the lamp's size it will give you much softer shadows.





related: Meaning of Sun Lamp Size?