Cornwell got his start working at the Australian Broadcasting Commission (ABC) in Sydney, Australia.
[citation needed] Cornwell left ABC in order to create Trephine Production Studios, which he used to complete his award-winning short Ward 13, a stop motion animation that enjoyed success at several international film festivals.
[1] Ward 13 received the FIPRESCI Award from the International Federation of Film Critics at Valladolid, and was short-listed for an Oscar nomination in 2005.
[5] Cornwell also directed the feature film Mercy, an adaptation of Stephen King's short story Gramma, which was produced by Jason Blum's Blumhouse Productions, McG's Wonderland Sound and Vision, and Universal Pictures.
[6] Mercy starred Chandler Riggs, Joel Courtney, Frances O'Connor and Mark Duplass.