I think klodolph's point is still on the mark. I don't read it as: "The 3D in this WWI footage was faked in post." Which is obviously true. I instead read it

I think klodolph's point is still on the mark. I don't read it as: "The 3D in this WWI footage was faked in post." Which is obviously true. I instead read it as: "The reason the 3D looks about as good as you're used to from other films, is that most of those modern films _also_ faked their 3D in post."