The modern “making of” film tends to operate as an exercise in banality. A brief featurette tacked onto the physical release of the film or distributed for promotional purposes online they rarely offer more than a collection of talking heads images of a director gesticulating behind a camera or — more often nowadays — footage of a special-effects team hunched over design software. It’s a shame as the opportunity to delve into the material production of a film as well as its conceptualization is a thrilling premise. When done well documentaries about films and filmmakers resonate beyond the work in question provoking thoughtful ideas about cinema and the arts in general. With its fine Documentary Detours series Calgary Cinematheque has assembled five such examples.

The series is nestled under the broader title of Focus a perennial program that offers a thoughtful reconsideration of established genres or movements with a previous edition dedicated to the films of the French New Wave. Cinematheque president Brennan Tilley notes a goal of the series is “hopefully really digging deep into what a documentary is.” And it is fair to say that each film on display offers a wholly different answer.

The series begins on March 2 with a screening of Ross McElwee’s Sherman’s March (1986). Acclaimed as one of the high marks in 1980s non-fiction having subsequently been inducted into the National Film Registry at the Library of Congress the film has remained a cult classic for some time albeit one deserving of rediscovery. In Sherman’s March the “making of” element is in many ways incidental and emerges slowly. McElwee equipped with a 16mm camera and minimal sound gear returns to his home in the southern U.S. to make a documentary about General Sherman’s devastating Civil War march across Georgia. As he reunites with family and former lovers however McElwee’s personal history gradually overlaps with the military history he’s set out to document. With his ubiquitous southern drawl McElwee reinvigorates voice-over and verité techniques utilized less as devices for storytelling or education than as a personal recorder for his own anxieties about history relationships and filmmaking.

Sherman’s March is undeniably special but for sheer singularity the series centrepiece William Greaves’ Symbiopsychotaxiplasm: Take One (1968) is the uncontested champion. After cutting his documentary teeth working with the NFB in the 1950s and 1960s director Greaves returned to New York with a renewed desire to expand the form producing one of the most sincere oddities of American independent film. Over the course of one day in Central Park we watch Greaves and his free-form crew as they struggle against the limits of both documentary and fiction utilizing multiple cameras split screens and repeating dialogue shot with a mix of actors and park-goers. It is as dizzying and exciting as it sounds.

The two best-known films in the program look at some famous filmmakers’ offscreen chaos. Hearts of Darkness: A Filmmaker’s Apocalypse (1993) documents Francis Ford Coppola’s storied protracted filming of Apocalypse Now (1979). Culled from hours of on-set footage shot by Eleanor Coppola it is one of the rare documentaries that holds its own (and some argue surpasses) the original work. My Best Fiend (1999) is Werner Herzog’s personal recollection of his fraught relationship with actor Klaus Kinski over their five-film collaboration including the notorious production of Fitzcarraldo (1982). With clips archival footage and Herzog’s travelogue dispatches from former production sites it is tender but always aware of easy slippage between love and hate production and destruction. As for the fifth film of the program David Holzman’s Diary (1968) the less said the better. For all that the films in the Documentary Detour might revel in exposing cinema’s construction it’s always important to remember the value of surprise.