8 Details You Didn't Know About 1917
4. No Room For Error
In most movies made, there is some room for errors and mistakes, but with these long shots, there were always more at stake. The actors and crew had to prepare and rehearse for well over six months before they started shooting. But despite all the preparations and practice, some mistakes made it into the final movie anyway.
For example, when Schofield is running across the battlefield as the British are charging he crashes into a soldier, making them both fall. They get up and the soldier keeps on running to the front, while Schofield continues forward. This error was unscripted, but they still kept the shot. Maybe it feels so real because the actor knows that if he doesn't get up and catch up to the camera he would have to start over from the beginning of the scene again.
In the same scene there are explosions in the background, which was another reason for keeping the shot since they had limited materials.