Some further work with this image, in oil paints.

Here are 3 scales in oil paints--the bottom one is from a mixed chromatic black, the first two are with ivory black. With each one, I thought "Oh, that's fine." but with each NEXT one, the value changes became more even--mostly, expansion in the upper-mid value range. (Please excuse tiny dots at bottom of rectangles, they were from testing the next scale's values.)

early in learning photoshop...

Some photoshop experiments—not because I'm most comfortable with Pshop, but because I am learning. (Also traveling, some other media coming soon...)

I tried this exercise with an apple, let me know how I can improve. Not sure why but the big shadow in the middle of the apple looks like a hole instead of wrapping around the apple, how could I fix it to look correct?

I'm looking at the example given on the lesson page (sphere and torus), and thinking something is wrong about the way the dark area on the sphere under the top of the torus is treated. This dark area is marked as a cast shadow, and ambient occlusion is marked on it (as I believe correct), but its fuzzy edge is not identified as penumbra (as I believe it should be). AND its edge is also marked as a terminator; its bulk is marked as form shadow, and core shadow is marked on it—all of these incorrectly, IF it is a cast shadow). To be clear: it looks to me like the torus is casting a shadow on the sphere—the dark areas that wouldn't be there if the torus were taken away—and that this cast shadow has two edges: a fuzzy edge angled near the center of the sphere and a sharper edge near the lower right of the sphere. (Also, I'm intrigued why the sharper edge looks so sharp: my current theory is that the penumbra of the shadow is foreshortened.)