John, I like your lighting approach, but I'm wondering about the rendering of the picture you posted. On my little notebook computer it appears lighter than I think you may have intended. The black values don't seem dark enough and the colored areas seem a little hazy. I darkened your image somewhat until it looks better on my screen. I'm wondering how it looks to you. This could be a variable of this forum that we don't have a lot of control over -- monitor calibration. Maybe worth discussing...