From New Era films, the people who brought you "The Somme."
Reel 7 has excellent footage of Tanks (Mk V, unfortunately) and lots of rather implausible reenactment of battle scenes.
http://www.britishpathe.com/video/ypres-reel-7/query/battle+of+ypres
More reels from film also available on the site.
"Sometimes things that are not true are included in Wikipedia. While at first glance that may appear like a very great problem for Wikipedia, in reality is it not. In fact, it's a good thing." - Wikipedia.