Here is a layer of onion (Allium cepa). Onions have been cultivated for at least 7,000 years. Ancient Egyptians viewed the onion as a symbol of eternal life, with it's concentric rings and spherical shape.
Equipment used: Canon EOS Rebel T5i with a standard zoom lens (EF-S 18-55 mm) on a 49 mm long extension tube.
Software used: GIMP.