How lenses are made

Vitaliy_Kiselev

Vitaliy_Kiselev

A state-of-the-art MTF bench costs between $250,000 and $500,000. And it takes the time to test a lens. A single test run across the lens takes a minute or two. We need at least two angles (4 would be better) for each lens; plus, mounting, unmounting, and other things take time. So we can test a lens in 5 minutes; 12 lenses an hour. Let’s work 12 hour days and we can test 144 lenses a day. Unless it’s a zoom lens. Then you must test each lens at multiple focal lengths (3 or 4) so things down to maybe 3 or 4 lenses an hour.

http://www.lensrentals.com/blog/2016/02/optical-quality-assurance

One of interesting but slightly doom and gloom style articles that becomes easy to understand if you understand economic interests of authors (do not risk your money, rent top expensive lenses from us).

Vitaliy_Kiselev

Vitaliy_Kiselev

Vitaliy_Kiselev

http://www.focus-numerique.com/test-3144/reportage-usines-optique-made-in-japan-sigma-aizu-1.html

Vitaliy_Kiselev

80 years ago the story of T*-optics, which was to provide ways to ‘make glass invisible’, began at the ZEISS plant in Jena. The invention of anti-reflection (AR) coatings to reduce reflections from glass surfaces that are in direct contact with air represents one of the most outstanding innovations of technical optics in the past century. AR-coatings have considerably improved the performance of optical systems. It is only due to their invention that the construction of complex optical systems with many lens elements, such as high-quality retrofocus or zoom lenses, has become possible.

We will use photographic material to demonstrate how reflection-reducing coatings enhance the quality of photographic images. Moreover, we will discuss the functioning of antireflection coatings as well as the optimization of the reflection behavior of lenses in the process of optical systems development.

http://lenspire.zeiss.com/en/wp-content/uploads/sites/2/2016/04/en_About-the-reduction-of-reflections-of-camera-lenses.pdf