From the Discovery Channel I often watch a program called "How it's made" where they show different products being manufactured. Things like toothbrushes and shoes are done in seconds in the production lines.
I found a video of an episode from YouTube, where they show how they make lenses for cameras. Even though the lens maufactured on this video is not of Canon's or Nikon's, you can see how much work it involves. No wonder good quality lenses costs money, eh?
