Born in St Albans, Cooper was the son of a local photographer Thomas M. Cooper, who educated him from very early on in his profession. By the age of 16, he was working as an assistant at his father's shop on New London Road, St. Albans. He claimed to have gone to work for film pioneer Birt Acres in 1892, at the age of 18; this claim has however been disputed as Acres himself was working for Elliot and Sons up until 1895 and is felt unlikely to have hired an assistant before this time.