The Disappearance of the Pickelhaube.

Now I love it when the movies that I watch are historically accurate, because it shows that effort was put into the research behind the prop and set design. Now while the explosions and machine-gun fire are not accurate, the German's change in helmets some time into the movie is. The first helmet that we see is commonly referred to as the "picklehaube" which roughly translates to point bonnet in German. This one is the spiked one that we see in the first third of the film. Despite its apparent coverage and cool spike, this one was total garbage because it was made out of hardened leather, which stood no match against shrapnel. The only reason why they even wore these to begin with is that the picklehaube was of Prussian design, of sentiment to the German people and they didn't know how poor these would serve in modern war.  The one that is later introduced is called the "stahlhelm" or steel helmet in German. These helmets were excellent and can protect one's head from bits of shrapnel quite well. It definitely blew the Brodie helmet out of the water, and many nation's armies use helmets that decent from the stahlhelm today.