Area light has black edges

[AlistairM]

I hope someone knows what I'm doing wrong here...

I have an area light source as part of a lighting fixture symbol.

This looks fine in shaded mode, but when I use a Renderworks mode (e.g. Realistic Interior Fast in the screenshot below) the glowing part shows a black edge, even where it is behind other objects.

 

Do you know how I can turn off the black edge?

 

I have tried unticking 'Render geometry' but that didn't help.

 

Thanks!

 

 

 

 

[bjoerka]

Did you try to generate the area light with only a 3d polygon?

Looks as if your area light is made from an extrude object...