This 2014 documentary on the Somme presents a fairly conventional interpretation of the battle, but it has a number of unique features. Most important is the great selection the producers made for the film's expert "talking heads." The host, Royal Marine Major General Julian Thompson commanded a British brigade in the Falklands War and does an outstanding job of describing the strategic situation and providing a smooth transition to experts on the geology of the Somme, artillery fuses, machine gunnery, pigeon communications, mining operations, and a host other specialties. More than the story of the Battle of the Somme, this documentary is an introduction to the realities of battle on the Western Front, circa 1916.
Thanks to Paul Albright for recommending this video.