While most oenophiles are hobbyists, some may also be professionals like vintners, sommeliers, wine merchants, or one who tastes and grades wines for a living.
Amateur astronomers have made significant contributions to the profession, and hobbyists have made discoveries such as finding an unknown celestial body or celestial event.
Pied cockatiel plumage patterns vary significantly from animal to animal, giving rise to cockatiel breeders and hobbyists' heavy pied and light pied loose distinctions.