The Legendary ZUNOW 5cm F1.1 Ping-Pong — A New Chapter Begins
From a 1950s Japanese optical masterpiece to a new photographic adventure
Some lenses are made to take photographs. Others become legends.
The ZUNOW 5cm F1.1 belongs to both worlds.
Produced in Japan during the 1950s, the ZUNOW was among the fastest photographic lenses of its era. Its remarkable F1.1 maximum aperture, distinctive optical character, and rarity have made it one of the most fascinating lenses for collectors of vintage Japanese optics.
For me, however, collecting these lenses has never been simply about owning rare objects.
A lens deserves to be used.
An Extraordinary Discovery — No. 3570
In October 2026, I acquired a very special ZUNOW 5cm F1.1 from Irohas in Japan.
Its serial number is No. 3570.
This is an early example featuring the distinctive front design commonly known among enthusiasts as the “Ping-Pong” ZUNOW.
What makes this particular lens even more interesting is its Bell & Howell Eyemo cine-camera mount.
Unlike the more familiar Leica thread-mount and Nikon S-mount versions, this example was adapted for motion-picture equipment.
When the lens arrived, I was delighted by its exceptional condition. After so many decades, it remains remarkably well preserved.
The lens came with its rear cap but without a front cap. I subsequently fitted a Bell & Howell UV filter to protect the front element.
Its filter thread measures 54.5mm, and the aperture operates smoothly without clicks—a feature that I particularly appreciate.
The Mystery of the Eyemo Mount
Owning this lens immediately presented a fascinating mechanical challenge.
How could I mount an Eyemo ZUNOW on a modern Leica M camera?
The Bell & Howell Eyemo was a professional 35mm motion-picture camera, and its lens-mounting system differs considerably from modern still-camera mounts.
The ZUNOW itself also presents interesting questions concerning its focusing mechanism, mechanical construction, and flange distance.
Rather than permanently converting such a rare historical lens, I decided to investigate a removable adapter.
The objective is straightforward:
To photograph with the original ZUNOW while preserving its historical integrity.
The Eyemo-to-Leica M Project
My current project is to develop a dedicated Eyemo-to-Leica M adapter.
The initial approach uses a precisely fitted mechanical mount combined, if necessary, with an external focusing helicoid.
The design must satisfy several requirements:
Preserve the original lens without irreversible modifications.
Hold the lens securely and accurately.
Provide practical focusing.
Avoid mechanical interference with the Leica camera.
Allow the lens to be removed and returned to its original condition.
The project is still in its experimental stage.
The actual focusing arrangement and mechanical dimensions must be verified before a final adapter can be manufactured.
What Will the Photographs Look Like?
This is perhaps the most exciting question.
The early ZUNOW's optical design dates from an era when achieving an F1.1 aperture was an extraordinary engineering accomplishment.
I am not expecting the clinical perfection of a modern lens.
Instead, I am hoping to discover the unique character that made these early Japanese ultra-fast lenses so special.
How will it render faces? How will the background dissolve at F1.1? Will the Eyemo version show noticeable vignetting on a modern full-frame sensor?
These are questions that can only be answered by taking photographs.
The Story Continues
At Old Lens Junkies, my interest has always been in enjoying historical lenses rather than simply displaying them.
The ZUNOW No. 3570 represents another opportunity to combine Japanese optical history with practical mechanical design.
The adapter project is underway, and I look forward to sharing the first photographs once the lens can be mounted and tested successfully.
The lens is more than seventy years old. Its photographic journey is far from over.
Old Lens Junkies — Keeping Legendary Lenses Alive.
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