HI: I am trying to light a scene with HDRI. I received some free HDRI's files from 3D World. NOt sure if I am doing ti correctly. I have clicked on "Scene" and then under the "background" area of the "Effects" tab, I clicked on the HDRI and loaded my picture. I then added a gradient blue in the "Backdrop" area. Is this correct? Do I need to add lights to my scene after that. I presently have lights. But I am trying to light the scene from the HDRI file. Any help would be appreciated.

I think all you have left to do is set up the render in the render room.  Under the "Raytracing" box, check the "Light through trans." checkbox.  And under the "Global Illumination" box check the "Skylight" checkbox and an additional "Light Through Trans." checkbox.  I think thats all you have left to do.

Thanks. I am trying this now. Really appreciate your help.