The Five Obstructions (2003)
The Five Obstructions is a 2003 Danish film by Lars von Trier and Jørgen Leth. The film is a documentary, but incorporates lengthy sections of experimental films produced by the filmmakers. The premise is that Lars von Trier has created a challenge for his friend and mentor, Jørgen Leth, another filmmaker. Von Trier's favourite film is Leth's The Perfect Human (1967). Von Trier gives Leth the task of remaking The Perfect Human five times, each time with a different 'obstruction' (or obstacle) given by von Trier.
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