Canon CaF2 & MgF2 – 1

I visited Canon Optron with a BORG engineer. This is the place your fluorite lens is made.

What I realized as my misunderstanding and newly learned this time are

• CaF2 – fluorite’s raw material is still natural from the earth. I was confused between crystal and raw material. Man-made crystal is the origin of the fluorite lens. So I thought it was the raw material. That was wrong. There is still the raw material available as the natural resources to produce the crystal ingot as follows;

These are parts of CaF2 ingots Canon gave me this time. Thank you!! These will be displayed at NEAF as well. 

• Crystal vs glass : The crystal has the regularity during the process. So the quality is completely consistent and even entirely. Meanwhile the glass including the optical glass is regarded as a kind of “solid liquid”.  Strictly speaking or theoretically there are possibly variations, section by section.
• Most pure fluorite exceeds 99.9% transmission. Generally it takes a couple of months until completing the process. Longer, purer. But more expensive. I was told the crystal process was the big power eater since it requires the heating over 1400 Celsius continuously a couple of months. In fact, they had a big substation besides their building, which directly got the power from the high-voltage cables. I understood this was a part of the cost factors for our fluorite lens.

World largest fluorite lens, provided to Smithsonian Observatory. 400mm diameter. Several units were made for them.

 

— To be continued…….

~ by tedishikawa on March 10, 2019.