Thanks for the kindly comments !
Oonly sun+sky , sky =1 sun =0,25
No more light plane or portal mtl.
Pt+hd/ sample = 64 / max ray =200 / hd sampling = 1024
Light come from the back of the camera because a have a window here, so this is only the sky.
That's all folks and this is why i love so much Corona ! :)