Talk:Rendering engines comparison
From Blender for Architecture
Transparent shadows with Yafray
Take this file as example : Media:transp_shadow.blend.
This is the rendering with Yafray 0.0.9:
As you can see, the glass ball casts a dark shadow whereas it should be brighter due to the light going through the ball.
Photons could be used to illuminate the shadow but it is tricky and the result is weird. (Imagine you are rendering interior scene with sun light passing through huge glass windows...)
(To me,) It's a common issue of Yafray. However, Yafaray, the Yafray rewrite project seems to have resolved this issue. http://blenderartists.org/forum/showpost.php?p=739280