There is a man who possesses a résumé including three decades of hit Hollywood movies. He is one of the most famous stars on New York film sets and there is barely one star that passes through the Big Apple with whom he is not on a first name basis. He is not the man you might imagine however. Far from a glitzy megastar, this man is an extraordinary eccentric, formerly homeless but is a movie legend nevertheless. He is Radioman. He has appeared in more than 100 small parts and is seen as something of a good luck charm on sets. His story is a rags to…well…more rags tale but it is one of unconventionality and obsession encompassing the highs and lows of this enigmatic man.

Tom Hanks describes him as an institution, stating that “if you are on first name terms with Radioman, you know you have made it.” George Clooney and Josh Brolin extol his virtues and Robin Williams calls him “the surreal that keeps you real.” Praise comes thick and fast. Helen Mirren, Matt Damon, Meryl Streep, Tilda Swinton and Johnny Depp all pile on the admiration. Something Brolin says betrays a hint of a darker element to Radio’s relationship with the stars however. “Genuine and adolescent” may seem like a compliment, but it is entirely possible his presence on set is akin to that of a child, clowning around for their amusement but not to be taken seriously.

An obsessive fan, Radio spends his time cycling around New York, hanging out on the various film sets. He makes it his business to know more about the production schedules than the actors themselves. He appears in every movie but wishes to become a serious actor. Mary Kerr is a fly on the wall as Radio explains his life and shows her round his squalid apartment. The film sets are his refuge, they are a place that he loves and respects. His expression is that of sheer joy when discussing the movies but it is subtly tainted by Kerr as she delves into his more troubled past.

The film shows Radioman shooting a speaking part on the Robert Pattinson vehicle, Remember Me. He is exhilarated and nervous but pulls it off with a distinctly hoboish flourish. The disappointment is crushing as the scene is cut from the final movie. Radioman is a tender exploration of a saved soul, dedicated to a business and art form that seems to give very little tangible returns. Despite his devotion he still lives in poverty and the actors he calls friends may call him the same, but he is spirited by simply being involved at all. At once jovial and tragic, Radioman is addiction and redemption, questioning the core values of an industry set firmly in the limelight.

Radioman is out at the Prince Charles on the 17/18th October

Follow Jonathan on Twitter @joffglen