How to prevent and object from blocking light

[anbt 5]

Hello guys, I have a sphere that I use as a background for my render in Mantra. I am using an environment light with an HDRI texture as a source of lighting. My problem is that my background blocks the light from reaching my geometry.
I have tried using Light Mask and the Light Linker but without success.

Any ideas?

Thanks a lot

Edited January 3 by anbt

[anbt 5]

I figured it out (-shadow on my object in the render visibility) but now when I place another light that I linked to my background only, I see that it illuminates my other geo, the rays are probably bouncing back on my geo.
How can I avoid this and have this second light only affect my background and not indirectly illuminates anything else?

Cheers

Edited January 4 by anbt

[davpe 190]

not sure how your setup looks like but you can use Categories to make lights only affect specific objects. matching category patterns on both light and the object will make the light illuminate the object. otherwise the object is not affected.