A Visit To A Binocular Factory, Otsuka Optical Company

On a scorching hot day, I visited a major Japanese binocular manufacturer, Otsuka Optical Company, along with the staff from Hinode Optics.

Since I became interested in stargazing as a child, my binoculars have always been with me. However, I had never visited a binocular factory.

A binocular factory to me is what Disneyland is to children!

You can imagine my excitement when Mr. Miyano and Mr. Nakamura, Hinode’s staff, invited me to go with them.

In this article, I’ll tell you what the factory was like and the interesting stories Mr. Morimoto, the CEO of Otsuka Optical Company, told us.

I want to thank him for generously sharing his time and letting me take a lot of pictures.

In the drawing-room

We were shown into the drawing-room, where there were a lot of museum-like treasures: Precious classic binoculars.  One of the oldest pair was made in 1887 by Gorz, a German manufacturer.

These are extremely rare and surprisingly, prisms were used.  The first prism binoculars were invented in 1854, so the binoculars in front of me were from the very early stages of prism binoculars.  They were donated to Otsuka Optical Co. by a collector in the 1960s.

In the showcase, there was a long thin box.  This was made for Japan’s first Olympic Games in 1964.  Opening the box carefully, I found five pairs of opera glasses in Olympic colors. How cool!

Mr. Morimoto then approached us to have a business meeting with Hinode’s staff.  One of the most interesting topics they discussed was the lenience of JIS, Japanese Industrial Standards.

Some companies try to take advantage of the JIS leniency so that their products will be more attractive to consumers.

Usually, 8×42 binoculars (magnification: 8x, aperture: 42mm), have a 7.8 degree field of view.  However, consumers may want an 8.0 degree field of view.  Labeling 8×42 as having an 8.0 degree field of view is within the JIS tolerance so, it is not illegal.

If they simply, physically try to enlarge the field of view, the binoculars will have another problem: the decreasing of peripheral light.  It does not make sense to widen the field of view if the peripheral image gets worse.

Like many people, I want wide-angle binoculars.  However, now that I understand what many makers are doing with the numbers and engineering, I don’t think we should give up on better quality binoculars just for a tiny difference in the field of view.

In the factory

There were several employees working in the factory, including part-timers.  They were so focused and working so quietly and patiently that I didn’t dare speak to them.

Before getting here, the main parts of the binoculars had already been assembled in China, where they have their factory.  Nevertheless, this factory in Japan plays a vital role in making sure that the final product is of high quality.

The final adjustments and checking procedures are essential. Otsuka Optical can produce high-quality binoculars by getting involved in the final process.

The collimator

The collimator tester has a small monitor in front.

The collimator is for testing if both of the optical axes are parallel.  Some people get a headache or feel dizzy when they look through binoculars with optical axes that are not parallel.

The monitor shows a grid to check the difference between the two optical axes.

In this section, they check whether there is dust inside the binoculars by looking through them at a bright box.

Tiny dust particles on the lenses do not affect the image, but the Japanese customers tend to be obsessed with dustless binoculars. It costs a lot to hire people to spend time looking for tiny dust particles inside binoculars.

The optical resolution tester

This tester excited me.  This machine checks the optical resolution which is closely related to the sharpness of the image.

Putting a pair of binoculars between the ocular lens and a rifle scope, which enlarges the image, you can see numbers and slits.

If you can see a particular slit clearly, the corresponding number indicates its resolution.

Hinode’s 8×42-D1 binoculars showed the second-best resolution, which is far better than the average. I could see the second narrowest slit.

Binoculars cannot cheat this tester.

I happened to have my Zeiss’s binoculars, classic 7×42 BGAT*P*, with me for another meeting, so I asked them to test my pair.

The result showed that it has an excellent resolution in the center, as expected, though the image was bluish.  The resolution tester also shows you the color balance of the lens coatings.

I’ve realized how much the coating techniques had improved over the past decade. The latest coatings for mid-price range binoculars are far better than Zeiss’s best binoculars a few decades ago.

Anyway, I was relieved to know that the resolution of my Zeiss pair was excellent.

We tested another pair which is popular among enthusiasts and is often sold for high prices on internet auctions.  The result, however, was not good.

The resolution was not great, and the image was greenish. If someone inspected the resolution of all the binoculars being sold and published their findings, the binoculars’ market would be very different!

Dare I say again; “Binoculars cannot cheat this test!”

Golden Era of Japanese binocular manufacturers

Mr. Morimoto knows about the golden era of Japanese binocular manufacturers in the 1960s.

In those days, each supplier specialized in just one component.  The binocular manufacturers bought each component from these suppliers, assembled them and shipped them to the U.S. market.

In those days, 3 pairs sold to U.S. consumers could earn enough money for a person to live for a month.

Such a gold rush did not last long.  It ended in the late 1960s.  Some companies designed their binoculars themselves to differentiate their products, and they successfully survived through the following hard times.

However, most companies went bankrupt.  Otsuka Optical Company is one of the survivors.  In the late 1980s, Japanese manufacturers looked to China for lower labor and manufacturing costs.

The reason they chose China was that there had been binocular manufacturers there for military use who had copied Western designs from makers such as Zeiss, Leica, and Swarovski.

However, quality control has always been a pain in the neck.  Most companies in China still don’t try to design their own binoculars.  They prefer copying other, successful products.

The history of the rise and fall of Japanese binocular manufacturers really impressed me.  I do not know what will come next, but hard times may continue as binoculars have become a common commodity.

I hope that Japanese manufacturers like Otsuka Optical will survive and continue to produce high-quality binoculars everyone can afford to buy.