The method used to make Birds of heaven it has been called Supermarionation and involves the use of super-sized puppets with an audible lower lip that can automatically follow pre-recorded dialogue.
A unique approach was used for a series of projects filmed by AP Films (now known as Century 21 Films) including The Four Falls, Supercar, Fireball XL5, Stingray, Captain Scarlet and the Mysterons, Joe 90, again Secret Service. When Supermarionation declined after the 60s, Birds of heaven it continued to have a strong cult following, mainly due to the unique puppetry and special effects employed in making the series.
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