How do the lens companies do it?

[mohan]

hi!

I am curious about the production of lenses and who does what in the lens industry.

Do the lens companies produce the raw material (glass) by themselves, or are there companies just working with producing glass needed for lens quality?

Who does what in this lens business? raw materials? designs? manufacturing?

It is quite fascinating to learn about optics and their design and manufacture!

Cheers and Thanks.

Mohan

[Arne Croell]

Most of the companies producing lenses buy all the glass from the few manufacturers of optical glass that exist. The most common optical glass companies are Schott (Germany), Hoya, Ohara, Hikari, Sumita (all in Japan), Pilkington (UK) and Corning (US), there are a few more, e.g. in China. The countries indicate only the country of origin, these companies have production facilities all over the world. A few companies (e.g. Nikon) make a few special glasses themselves, or may develop them themselves and then farm out the production. The lens design software packages have built-in glass catalogs nowadays, with all the current and some old glasses of the major manufacturers.
In the case of LF lenses, design and manufacturing is usually under one roof, at least in the case of Schneider and Linos-Rodenstock. For other, more mass-produced lenses, they are designed by the company that is on the label but may be made elsewhere. A lot of the 35mm and digital Zeiss lenses are made in Japan, not in Germany, the same goes for the "Leica" lenses on the Panasonic digicams. But for LF, I assume the major players (Linos-Rodenstock, Schneider, Fuji, Nikon until recently) make their own stuff, the smaller ones (Congo, Docter until 1996), too. Of course there are the house-brand lenses from Sinar (Sinaron) and Calumet (Caltar) - those are made nowadays by Linos-Rodenstock, previously also by other companies.

[Ernest Purdum]

As an historical note, it was really the work done at the Schott glass works in Jena that made continuing progress in lens design possible. Without a selection of glasses of differing dispersion the lens designer is stymied. Friedrich Schott worked with Ernst Abbe, the Zeiss designer, to fill this need.

Some of the start of glass works outside of Germany is due to the two world wars making German glass temporarily unobtainable.

[Robert A. Zeichner]

Ernest makes an important point. Much of what we know about optical glass is owed to the efforts of Abbe and Schott at the Zeiss company around the turn of the century (the last century). By 1900 there were around 67 varieties of optical glass in the Zeiss catalog. Back then, the Zeiss company was operated more like a scientific foundation than a for profit competitor and due to that, many other designers were able to buy Jena glass and later, even license Zeiss designs (notably, the Tessar). The labor intense work to design and manufacture optics back then commands our highest respect. Today and for the last few decades, really, computer aided design and machining technology have reduced to a small fraction, the time it takes to conceive and bring to production a lens design as well as making it practical to do things like making aspheric elements.

Along the way, many optical manufacturers have made contributions that improved glass and coating and have been adopted as new standards of manufacturing by others. An example that comes to mind is Nikon and their crucible design that reduced the bubbles created during the melting process.

What some don't realize is that with the international push to reduce the use of environmentally harmful materials, glass makers have had to re-invent the formulas for making optical glass to reduce use of lead, for example. I don't think in this competitive world, we will know as much about these new secret formulas as we might have in the past.