My lights turned out black in rendering!

---This article applies to pre-1.6 versions of Corona Renderer. In newer versions "prevent black appearance" option was added to force the light to be always visible as white/colored instead of black---

Corona Lights and mesh emitters with "directionality" other than 0 will always produce such result when seen from a certain angle. It is physically correct as when directionality is enabled, some of the light rays do not reach the camera.


Lights in viewport:

Render, directionality = 0

Render, directionality = 0,5