Video: How lenses are made part 2

[Woogie]

http://www.canon.com/camera-museum/t...t/f_index.html

Definitely worth your time checking these videos out. It's amazing how much work goes into designing and building these lenses. The average joe wouldn't appreciate good glass unless they've got a D/SLR.

Very cool stuff.

[Percy]

Good find!

I noticed that the initial polishing stages are high speed - not really a good thing if you want precision out of your optics. Heat, expansion, zoning...all the nasty stuff happens. When they were testing the lenses on a ronchi test, they were kinda cheating. You would use green light, not white light. Green light and the interferometer as well as a complete fringe diagram would tell the whole story.

Canon won't publish them due to obvious reasons. But then neither will any other mass produced camera lens manufacturer.

Now if they could take a tour behind the scenes at Telescope Engineering Company or Astro Physics. Lens manufacturers would learn ALOT from them as these two companies are considered THE best in the world...and the japanese reluctantly admit it.

BTW...Canon would still be considered second rate when compared to the Rochester lens machine. This is a multi million dollar machine used to produce military/astronomy optics. Something which Astro Physics has and uses for it's optics.

Still, great find. Quite entertaining!

Percy

[UberNoob]

Originally Posted by Percy

Good find!

I noticed that the initial polishing stages are high speed - not really a good thing if you want precision out of your optics. Heat, expansion, zoning...all the nasty stuff happens. When they were testing the lenses on a ronchi test, they were kinda cheating. You would use green light, not white light. Green light and the interferometer as well as a complete fringe diagram would tell the whole story.

Canon won't publish them due to obvious reasons. But then neither will any other mass produced camera lens manufacturer.

Now if they could take a tour behind the scenes at Telescope Engineering Company or Astro Physics. Lens manufacturers would learn ALOT from them as these two companies are considered THE best in the world...and the japanese reluctantly admit it.

BTW...Canon would still be considered second rate when compared to the Rochester lens machine. This is a multi million dollar machine used to produce military/astronomy optics. Something which Astro Physics has and uses for it's optics.

Still, great find. Quite entertaining!

Percy

i consider canon to be 3rd rate back in the days when Nikon was dominating the SLR scheme heh

[Percy]

Mid 70's, yes. Nikon was tops. Canon didn't take the market lead until 1989 - when they introduced the EOS1 series.

Canons lenses have been consistently better though, IMO, in a same focal length/focal ratio comparo. That's more often than not.

Canon already had the 300 2.8, 400 2.8, 500 4.5, and 600 4 way back in 89. Nikon didn't come out with something similar (with AF) until 93. Too late...Nikon users jumped ship to Canon white lenses since they predicted the market.

Percy