In “L’amour fou,” Pierre Thoretton’s documentary feature on the industrialist Pierre Bergé and his partner, the fashion legend Yves Saint Laurent, romantic and working relationships take a backseat to the tempestuous life and times of the late designer.

After enjoying an illustrious career as a fashion designer and icon, Saint Laurent passed away in 2008 at the age of 71 with a public send-off worthy of royalty. The streets of Paris were packed with onlookers as his body was transported to its final resting place, and it is in the aftermath that the first narrative begins. As self-described “undertakers of art,” Saint Laurent and Bergé amassed, over a period of decades, a private art collection to rival a modest museum. Once widowed, however, Bergé sought to breathe new life into the treasures he and Saint Laurent had cherished, resulting in a massive auction held by Christie’s at the Grand Palais in February 2009, the proceeds of which Bergé pledged to AIDS research.

But despite the couple’s ties to the collection being the purported premise of the film, it is the second narrative, the biography of Saint Laurent, which effectively supplants the first. Scenes of the flat they shared together for decades, interspersed with Bergé’s commentary, gradually segue into a lengthy chronicle of Saint Laurent’s life, beginning with his succession to the Dior fashion house at age 21 (Saint Laurent and Bergé first met at Christian Dior’s funeral) through his retirement in 2002, until he succumbed to brain cancer six years later. Through photographs, footage and personal accounts from close friends, Saint Laurent emerges as a tortured artist who, throughout his career, constantly battled depression and substance abuse. Even after the designer came into his own and achieved success with his namesake label, Bergé lamented that the only time Saint Laurent seemed truly happy was when the audience broke into applause after the unveiling of a new collection.

Featuring footage from past runway shows, sketches and photographs of Saint Laurent’s work, as well as inside looks at the couple’s sumptuous Parisian flat and Moroccan getaway, “L’amour fou” is a visual treat. Ever inspired by his surroundings, the designer leaves no doubt he was as stylish as the clothes he produced. A true visionary credited with revamping haute couture early in his career, Saint Laurent’s eventual retirement was precipitated by his belief that the industry had been taken over by tradesmen.

Through the lenses of Bergé and those who knew Saint Laurent best, “L’amour fou” provides a privileged look into the private life of a legend. While fashionistas and diehard YSL fans will probably enjoy the experience regardless, lay people (such as myself) are more likely to find the documentary too long and too disorganized. Although Thoretton attempts to make the designer’s life dovetail with Bergé’s coming to terms with his death and finding meaning in the art collection they shared, the narrative ultimately feels muddled. Bergé still features prominently in telling his partner’s story but loses agency as the dominant voice. Likewise, even though the film concludes with footage of the auction, after Saint Laurent’s exposition, the art collection seems like a mere afterthought.

Despite the lack of narrative cohesion, Thoretton succeeds in composing a beautiful elegy, made more poignant by Bergé’s constant presence. In the film’s final scenes, he calmly observes the auction, hoping that each piece can bring its new owner as much satisfaction as it brought him and his partner.