The scope /optic stuff is arounf the 8:00 mark
https://www.youtube.com/watch?v=OWa3F4bKJsE
The scope /optic stuff is arounf the 8:00 mark
https://www.youtube.com/watch?v=OWa3F4bKJsE
Juice, have a look at some of the videos posted by Tom Lipton (OxTools)
He has several very interesting videos about surface plate calibration (down to millionths of an inch) as well as lots of practical videos about lapping and the use of optical comparators and showing interference fringes.
https://www.youtube.com/results?sear...tools+flatness
He wont hear ya......
The lenses groups in the then West German made Zeiss Diatal and Diavari scopes of the late 80's were held together by molecular adhesion measured in the millionth's of an inch. Similar to how Johansson blocks work. They weren't cemented together.
I didn't look at the video but I recall one of our seal suppliers advising us the surfaces of their mechanical seals are measured in lightbands for flatness. Sounds techhy. I liken it to how @10-Ring describes this as we can often pick up one part of the seal with the other just by mating the two faces together.