Almost the first thing you see on entering Real to Reel: A Century of War Movies (to 8 January 2017) is a ghostly monochrome sequence of a gigantic explosion. It is of a mine going up at precisely 7.20 a.m. on 1 July 1916, at Hawthorn Ridge on the Somme. Ten minutes later many thousands of British soldiers climbed over the top of their trenches and began advancing towards the German lines. By the end of the day the British Army casualties numbered 57,470, more than 19,000 of them dead.

Just as the mechanised slaughter of the Somme marked a catastrophic new era in warfare, the sight of that blown mine – 18 tons of explosive – fired the starting gun on a new art. Two cameramen, Geoffrey Malins and John McDowell, were at the front line in France to capture it, one among many dramatic images they would gather and shape into a cinematic feature.

When released in August 1916, The Battle of the Somme caused an immediate sensation among a public utterly new to the imagery of conflict. It would be seen by more than 20 million people in Britain at the time. The war film was born.

The timing of this exhibition at the Imperial War Museum could not be more appropriate in the week of the Somme’s centenary. It has been thoughtfully curated by Laura Clouting, who may be assured at least of a public whose appetite for the spectacle of war has held firm since the carnage of 100 years ago.