Mm. Thanks for the offer. I'd prefer to recreate the behavior with another prop, tho (I did the light lab with a pair of planes, one with a simple map containing one black spot I made in GraphicConverter) -- the meshes I'm using are of course DAZ property and all that rot. Just to make sure I did it right the first time (and the fourth, and the eighth) I'm rendering one more test shot with everything but total photons cranked up to the top of the slider. Looks to be another four hours before THAT finishes! Meantime I have a solution that will work for at least this image, perhaps others. Render twice, combine in PhotoShop, use alpha channel to reveal the spot-lit render only where it is needed to clean up eyelashes, hairline, and other problems with the GI render. Oh...I tried another cute trick in the interim. Scaled the entire scene 100x. It changed a bit, but the black shadows didn't move enough to notice.