To mark 100 years since the Battle of the Somme, BBC4 is giving us another chance to see this fascinating documentary, which reveals the secret history of amateur photography in World War One, from both the British and German perspective. Many of the personal snaps proved remarkably different to the famous official war photographs that we’re familiar with. The film also delves into the lives of the soldiers behind the lens, and uncovers stories and messages hidden within. Striking similarities are drawn as we follow the families of the photographers from both sides and it’s a poignant and heart-warming watch. Further examining the conflict through art, War of Words: Soldier-Poets of the Somme is showing first (9.00pm).