Advanced optical glass and master lens grinding
"Discussions with manufacturing are much more important than the design on paper," says Yokoyama. Kunio Yokoyama and Yasushi Ogata, both of whom were charged with lens design, made frequent trips to Olympus Opto-Technology Co., Ltd.'s lens processing plant in Sakaki, Nagano Prefecture.
When a single lens is made up of 10 separate lens plates, basically you have to select the best optical glass for each lens. But this is one of those things that are a lot more difficult in practice than it might appear in theory. As one designer put it, "it's like trying to put together a puzzle."
And the Four Thirds system makes it even more complex. "A small size like the 4/3 type requires even higher performance, so naturally this means greater precision in each lens part as well," says Kazuo Ushiyama, who led the lens-processing group. He continues with a mind-boggling analogy for the level of precision required of the lenses: "If we had to process an area the size of Tokyo Dome to make it flat, the height of the mound would have to be made less than that of a hair."
And when it comes to the precision needed to grind a lens: "No machine can do it. This is the domain of the master craftsman, and it's something that only a human can do," he emphasizes.
Since the CCD is smaller with the Four Thirds system, you should be able to get the telephoto lens and the like smaller. This is an advantage that all the designers proclaim. If you want to make it lighter, however, you have to use a lighter type of optical glass.
"The optical glass that we use is lead-free, that is to say it does not contain any lead," responds Ushiyama. "In its place, the glass contains titanium, and so the glass itself is extremely light," he continues.
Is the use of lead-free glass a trend in the lens industry as a whole?
"I think it depends on the attitude of the manufacturer. At OLYMPUS, we don't use any optical glass containing lead, in consideration of the environment."
Breathing life into lenses
Last year's announcement of the end of OM system production was a sad event for the lens division. It marked the end of a 3-year "lens cram school." But then, the plans for the E-1 rushed in to fill that void. "It required quite a bit of precision, so we all pulled together to meet the challenge. A person's skills really are his treasures."
A master grinder is said to talk with the lens during grinding; the master understands the curvature of the lens, and knows what must be done at each moment, while at the same time looking ahead, and adjusting accordingly. "In a sense," says Ushiyama, "this job has similarities with the job of a swordsmith." Ushiyama always has something interesting to say.
But if you thought that such a master grinder must be some grizzled veteran, you'd be wrong. "No, actually most are in their late 20s to early 30s. They are always looking for a better way under their own initiative."
When they had a working E-1, they started getting visitors from overseas Group companies. "When I heard someone comment that I was breathing life into the lenses, I got a chill down my spine." And the group leader does not forget to add: "I am also happy to have been the last generation to have the experience of making lenses for the OM system."
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Yasuji Ogata
Imaging System Group
Opt-R&D Department, R&D Division
OLYMPUS CORPORATION
Bought an OM-1 during his second year of high school. After coming to work at OLYMPUS, he was involved in the design of interchangeable lenses for the OM system and compact camera lenses. He brings this experience to the design of the E-1 lenses.
Kazuo Ushiyama
Lens manufacturing Group
Olympus Opto-Technology Co., Ltd.
This leader in protecting the prestige of the ZUIKO brand is passionate when talk turns to the "lens cram school" that the project gave the opportunity for, or his talented young masters. He has been involved in lens processing since the OM interchangeable lens. |
