his documentary focuses on the making of the 235-minute, silent epic Napoleon, the masterpiece of French director/writer/actor Abel Gance. Napoleon showcased Gance's talents with the camera, his use of multiple-images (like a split screen), and his handling of crowded action scenes -- all brought forward in this documentary by his later assistant, Nelly Kaplan. While Gance was shooting Napoleon in 1925-26, he and his crew were also being filmed for a documentary titled Autour de Napoleon. The only extant reels from that documentary are included in this film, as well as views of Gance's unique "triptychs" -- three different scenes lined up side-by-side across a super-wide screen to convey the effect of a panorama, or of three separate interludes. Nelly Kaplan put together this documentary using old footage, such as Gance filming the famous snowball fight at the Brienne military school and still photographs and excerpts from Gance's production diaries.

Overview from themoviedb.org