OK, here's the sitch... I tried different renders using all of the mentioned solutions... Final Verdict: Full raytracing: This has absolutley no effect on the artifacting in the render. What this does do is sharpen the reflection on the sphere/cone structure. Good thing, but not a viable workaround. Adds to render time only slightly. Interpolation: This did not visibly affect the image, except to add to render time. No go... Photon Counts: This changed the size of the artifacting and made it smaller, but did not remove the problem. Also added to the render times.... All settings to best/lowest value: This solved the problem, but it went from a 2 minute render to a 40 minute render... gotta be a better way. Final conclusion to render artifacts (after much testing): Change the lighting quality out of fast mode to best mode. This allowed the lighting to fully reflect off the white base object and be accurately portrayed. Artifacting was removed and the final render time was only 5 minutes more (at 7 minutes total) than the original. Thanks for the excellent advice, guys, as it gave me a starting point for figuring this out. I'm going to keep working on HDRI as a means for natural lighting. Just FYI, setting a spherical camera in a scene that is 2:1 ratio will yield a HDRI lat/long map. Use GI and you can just translate the image using HDRshop to an HDR image that carrara can use! Ken