Excellent composition worthy of posting in a modern art museum. Great use of light to get such well-defined color steps at each onion layer. Black bacground lends a good balance. I had this as one of my top five for this challenge.
This is very interesting to me. I like the tones of the grays and how it almost looks like a painting. Makes me think of Mark Rothko in a (circular) way. This is probably not going to score very high at DPC, but i like it quite a bit. Good job on the choice of subject