Here’s a behind-the-scenes documentary in the tradition of Burden of Dreams­, Les Blank’s making-of film about Werner Herzog’s Fitzcarraldo. This one even has a wild-man actor, Jorge Thielen Hedderich – though he’s not quite a match for Klaus Kinski in the ego stakes. Actually, he’s not even an actor by trade, but he is starring in a movie about his own life directed by his son Jorge Thielen Armand. Or, at least he’s meant to be. His rum-fuelled all-nighters, tantrums and fits of rage are constantly threatening to bring the production crashing down. Though when El Father – as everyone on set calls him – is in a good mood, on full-wattage, his charisma is dazzling.

This documentary is directed by Armand’s partner, Mo Scarpelli. At times it feels frustratingly light on detail about the film she is observing being made: it’s Armand’s second feature, La Fortaleza. What we can glean is that it is the story of how El Father lived in the Amazon in the 1990s, working in illegal gold mining and drinking heavily. Scarpelli is not so interested in whether her father-in-law can be tamed – though she does show the crew sneakily watering down his rum. Instead, she zeroes in on the dynamic between father and son – and she’s got an uncanny instinct for knowing which of their reactions to shoot. When El Father breaks his finger, it’s the son’s face she films – wincing as his dad twists his own bone back into place.

El Father is clearly a rampaging narcissist who loves being the star of a movie about himself. But what about Armand, the quietly intense film-maker: what are his reasons for making the film? Scarpelli gently and sensitively suggests he has grown up in the shadow of El Father. He left Venezuela aged 15, and the film is his way of getting closer to his dad, perhaps, and possibly of punishing him – or at least forcing him to come face to face with his failures in life and as a father. It’s thought-provoking stuff.

• El Father Plays Himself is released on 6 August in cinemas.