from kaenon to basn5

from kaenon to basn5

Steve Rosenberg founded Kaenon in 2001 and created the SR-91 lens sailors still wear. basn5 is the frame he and his son Jacob built next: everything fifteen years of Kaenon and six years of Tajima Direct taught us about what fails on a pair of sunglasses, answered in one frame, standard with Tajima polarized lenses.

We brought it to the 2026 Rolex Big Boat Series in San Francisco as a sponsor, alongside Tajima Direct. For the full story, lens first, read From the Founder of Kaenon on Tajima Direct.

steve and jacob rosenberg. father and son, co-founders.

what we learned. what basn5 does about it.

Fifteen years of building Kaenon. Six years of nearly every frame, from every brand, crossing the Tajima Direct lab bench. The same failures, again and again.

• paint peels. No paint. The color is in the material, so there’s nothing to peel or chip.
• hinges fail. A patent-pending stacked hinge, made with an elite Austrian hinge maker. Strong. Precise. Serviceable.
• rubber breaks down. No rubber. The frame material itself grips, with nothing added to break down or peel off.
• parts can’t be replaced. Every part is serviceable. A broken part never means a new pair.

The sum of it: the pair you stop replacing.

the stacked hinge. patent-pending, replaceable.

light. comfortable. durable.

One advanced material. Highway 1 and Fort Point weigh 19 grams. Davenport weighs 25. Fit adjusts at the temple tips. Salt, sweat, sunscreen and skin oils wipe cleanly off.

Three parts, one instrument: frame engineered in Germany, hinge invented in Austria, Tajima polarized lenses made in Japan.

the lens, carried forward

SR-91 was made from Tajima Urethane™, a patented lens material named for the small town in Japan where it is made: the optics of glass, shatter- and impact-resistant, and very light. The Kaenon and SR-91 names went with the sale in late 2015. The lens technology, and the Japanese partners who make it, stayed with Steve. Ten more years of refinement have brought sharper detail, richer color and longer life. Today it is called Tajima, and every basn5 comes standard with it.

made to your prescription

Prescription is available on every basn5 frame, with the same Tajima polarized lens made to your Rx.

still wearing your kaenons?

If your Kaenon frames are still going strong, Tajima Direct will custom-cut new Tajima lenses for them, prescription or not: Tajima lenses for Kaenon · prescription lenses for Kaenon. The same lens goes into any frame, from any brand.

the short version

• 2001. After eight years at Oakley, Steve founds Kaenon and creates the SR-91 lens.
• 2015. Kaenon is sold. The names go with the sale; the lens technology stays with Steve.
• 2020. Steve and Jacob launch Tajima Direct: the lens, now Tajima, for any frame.
• 2026. basn5: the frame, rebuilt around the lens.

questions

who founded kaenon?

Steve Rosenberg founded Kaenon in 2001 and created its SR-91 polarized lens. Kaenon was sold in late 2015. Today Steve and his son Jacob lead basn5 and Tajima Direct.

what is steve rosenberg doing now?

With his son Jacob, Steve co-founded Tajima Direct in 2020 and basn5 in 2026. He still works with the Japanese lens partners who make Tajima polarized lenses.

is basn5 related to kaenon?

basn5 comes from Kaenon’s founder, Steve Rosenberg, and his son Jacob. It is a new brand and a new frame, not a Kaenon product. Its lens comes from the same lineage as SR-91, with ten more years of development, and is now called Tajima.

does basn5 come in prescription?

Yes. Every basn5 frame is available in Rx, with the same Tajima polarized lens made to your prescription.

can i put tajima lenses in my kaenon sunglasses?

Yes. Tajima Direct custom-cuts new Tajima polarized lenses, prescription or not, for Kaenon frames and for any other brand.

highway 1, davenport, fort point.

highway 1, $365. davenport, $395. fort point, the classic aviator, $395. All with Tajima polarized lenses. All available in Rx.