added lights having strange effect on HDRI exterior lighting

I have two images. This is the render layer of the building and lighting. First, I will say that this lighting discrepancy occurs when rendering all layers as well. In order to simplify, I just rendered the building exterior.

1st image shows the correct exterior lighting with HDRI only, No point lights and mesh emitters.

2nd image shows rendering with same HDRI as first image and 1 point light at each patio roughly where red dot is shown. Power at 20 watts. On the inside I have mesh emitters for the chandeliers and eight point lights at the wall sconces set to a power of 40 watts each.

You can clearly see that when I render same scene, same render settings but adding the point, and mesh emitters the exterior light changes dramatically.

Can anyone explain why this is so?


Seems to be a bug when rendering with Path Tracing. I submitted it to the bug tracker. They told me to render it with Branched Path Tracing with sample all lights checked. It renders fine that way. It takes a lot longer to render with Branched Path Tracing, so I hope this issue can be resolved for Path tracing.

Thank you for information, I’ll try to take that in memory, unfortunately I use Cycles so rarely that when I do that, I do not remember anything about render settings.


A note from Blender Bug Trackers. Not a bug. Direct Clamping settings is the issue. Scene did not even need Direct Clamping. Set it back to zero and the lighting is fine

Good to know, thanks!