A virtual lens factory that lets you know how the lens of the camera is made

A virtual lens factory that Canon, one of the leading camera makers, has installed at its site. Here, it is now possible to watch a state of lens creation that can not be usually watched in movies, such as a material processing step starting from the step of preparing the glass raw material before becoming a lens and a lens assembling step of incorporating a lens inside the camera I will.

Details are as below.
We use "EF 500 mm F4L IS USM" for the camera for the assembled movie, but it seems that it requires veteran skill to incorporate the lens.

Canon Camera Museum | Technology Hall - Virtual Lens Factory

The bottom movie is how to make a camera lens broadcast on the Discovery Channel. I get a different impression from Canon's factory.
YouTube - How camera lenses are made