-I thought the scene could be lit by the just the image mapped on the sphere, without radial lights, yes, no? ~Yes but it has to be rendered in true ambience mode -To light the scene by just the image what are the settings? (so far I've been unsucessful with this) ~True Ambience and a lot of fiddling with the ambient values of each material. -Is a light dome necessary? ~no but it really looks best with atleast a few lights. -Does the sky need to be disabled? ~Yes, the sky has to be black (otherwise artifacts) and the sun needs to be disabled. -Does the sphere need to be transparent? ~What sphere? The hdri sphere should not be transparent. Nor the sphere outside of it. -Is this just for reflective surfaces? ~No, though it seems to have the most pow when used with them. Pow being popular appeal =P. Anyway, you can use it with non reflective surfaces so long as you turn on true ambience. -I noticed the shadows were hard edged, I assume I change this in the light lab for all the lights used, yes? ~Or render with soft shadows and crank the shadow edge blur up in the light lab. Since you're going to render on true ambience, you might as well use soft shadows (and just a light or two). Furthermore, cool render. Although, I think you may have remapped the ldri incorrectly, or was it originally a hdri to begin with? Because it appears to have some strange distortions to it.