Thiebaud's work and my photograph aren't evidence of anything other than the fact that shadows in most every image you see (whether it be real life, a painting or a photo) are not black. And that you'd be surprised at how saturated the dark colors around you are. Notice how I never said, "Thiebaud's shadows aren't black, so you shouldn't use black." There were a lot of other words in between.
I should have clarified: The black squares actually weren't about dominance at all. I put a large swath of black next to those screenshots because color is relative, and to see how far from black the dark grays in those screenshots actually are, you need a comparison point.
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My other high school art teacher, Mrs. Totten (they taught as a pair), taught me a good lesson about photography. She would always defer to Mrs. Zamula on matters of photography because she readily admitted she had no photographic skill whatsoever. And she claimed that more people needed to acknowledge that fact, despite having their own digital camera. Well... my name is Ian, and I'm no a photographer.
But lucky for me.. that has absolutely no impact on my argument whatsoever!