'I Am Number Four' direct D.J. Caruso was driven "crazy" by the effects in the movie.

The filmmaker - who shot, edited and released the sci-fi movie, starring Alex Pettyfer and Dianna Agron in less than a year - was glad for the "help" of producer Michael Bay because he felt overwhelmed by all of the extra work.

He told BANG Showbiz: "Michael Bay was a first class producer. He allowed me the space needed to direct and was always there when I needed help. He was very helpful in Post and helped me conquer some visual effect shots that were driving me crazy."

D.J. also admits there are similarities between the film - About A Boy who his brought to earth as the last of a surviving species - and TV series 'Smallville', on which he worked on the very first episode about The Early Years of Superman.

He said: "'Number Four' does mirror Superman's Journey. I always made that connection. Also, a hero being reluctant to use his powers resonates in both 'Smallville' and 'I Am Number Four'.

"These similarities were helpful because I was revisiting themes that I had explored before."

'I Am Number Four' is released on DVD on June 20.