I've been a bit remiss in keeping the forum updated with contests, so just in case anyone isn't catching these on Facebook -
CGMood are running a contest on the theme of Autumn. It's open to renders that focus on Architecture, Still life, Nature, Conceptual art - it's up to you! The judges will be Bertrand Benoit, Juan Garcia, Daniel Reuterswärd and Johannes Lindqvist from Illusive Images, Massimo Gnocchi from CGMood - full details on how to take part (and win yourself a Corona Renderer license ;) ):
https://cgmood.com/competition