To explain about the umbra, it's directly by the moon, so it would just be complete darkness. Since a penumbra is in a spot where the sun's light overlaps the moon, you'll just be seeing light. So in short, for an umbra you'd see nothing but a dark circle. For a penumbra, it'd be the opposite. Nothing but light. I hope this helps!
The umbra is right by the moon so this would be a complete dark sphere with no kind of detail or any real textures whatsoever. The penumbra is in a spot where the sun's light overtakes the moon so you would be blinded by light.
