Mirams co-directed and photographed Broken Barrier, the only local dramatic feature film made in New Zealand in the 1950s, and later won a reputation for the children's television series he produced in Australia.
With John O'Shea (director), who would later become a partner in the company, he co-directed relationship drama Broken Barrier – the first fictional feature film to be produced in New Zealand since 1940.
[2] He then began to work on a series of children's television shows such as The Terrific Adventures of the Terrible Ten (1959), The Magic Boomerang (1965) and Funny Things Happen Down Under (1965) starring a young Olivia Newton-John.
In 1986, he produced a spin-off series from Secret Valley, entitled Professor Poopsnagle's Steam Zeppelin, which was successful in Australia and also in parts of Europe – most notably the United Kingdom, where it was shown three times between 1987 and 1998.
He continued to make quality children's television into the 21st century, and fulfilled a lifelong dream to do a remake of Oliver Twist, when he made The Fate of the Artful Dodger in 2002.
Although he was a pioneer in Australasian TV projects, especially on location color films, which were successful internationally, Mirams was largely unrecognized by the industry during his lifetime, rarely being nominated for awards.