An interview with Steve Rosenberg about basn5 sunglasses and Tajima Direct lenses
by David Schmidt 1 Sep 08:00 PDT
September 1, 2026
Jacob Rosenberg defining himself under the Golen Gate Bridge in 2025 © Bryan McDonald
When it comes reading the wind's interplay with the water's surface, few tools are more important than a great pair of sunglasses with high-quality polarized lenses. Choose the right pair and it can almost feel like cheating; choose poorly, and the day can be long, frustrating, and possibly capped with a headache stemming from squinting.
While I'm no master wind reader, I'm always looking for better tools for the job, so I started paying attention a few years ago when word arrived that the father-and-son team of Steve and Jacob Rosenberg had started a lens-replacement company called Tajima Direct lenses in March of 2020.
It didn't take long before I started hearing dockside whispers about the lenses' sharp, high-quality optics. The trouble, however, was that Tajima Direct sold lenses, and my trusty old shades were still in fine shape, so I missed the market's initial wind shift (as mentioned, I'm no master wind reader).
Then, late last spring, I heard about basn5 sunglasses, which Steve and Jacob also co-founded and own, and which come with Tajima Direct lenses.
A trip to the company website revealed some forward thinking: Prospective customers can choose between three frame styles, two frame colors, and 14 lens colors (plus RX options). Better still, the sunglasses-which the website refers to as "instruments"—are modular, and all parts can be replaced.
So, when Steve reached out to me with the chance to try out a couple of pair of basn5 glasses, I immediately accepted.
The first thing I noticed when I unboxed the sunglasses (a pair of black-framed Davenports with non-mirrored gray 15 lens, and a pair of brown-framed Highway 1s with brown 15 mirrored lenses) was the sturdy-feeling quality of the basn5's frames, which are crafted from a single material, and which are bereft of paint, rubber bits, and other extraneous decoration. The next thing I noticed was the lack of badging or visible branding, always a plus in my book, followed by basn5's unique and exposed hinges.
While hinges don't get the same fanfare as great lenses, they are often the first component to fail as the years unfurl. To overcome this, the Davenports—for example—use triple-stacked hinges that rotate around a single axis and that are each securely fasted to both the lens frames and the legs via six independent screws.
In practice, the intentionally exposed hinges on both basn5 testers deliver a satisfying articulation, and are basn5's only visible calling card.
Then there are the lenses.
The basn5 box arrived just in time to take my dog for his evening stroll, and I didn't even make it a quarter mile from my house when I noticed something strange: For the first time in my life, I started noticing—and/or separating—different shades of green. While I've been dogged by red-green color blindness my whole life, I had apparently reached a point of stasis where I just accepted that entire forests were a single color.
As for reading the wind's influence on the water's surface, as I've been doing all summer, there's no question that these lenses are in a class by themselves.
This latter point isn't terribly surprising, given that Steve Rosenberg has been in the optics trade (first at Oakley, then at Kaenon, which he co-founded with his brother, Darren, and sold in 2015) for decades and given that both Steve and Jacob are both accomplished (and decorated) sailors who have competed myriad in national- and world-championship level regattas. The two personally design, engineer, and develop basn5 sunglasses (and Tajima Direct lenses) from stem to stern, including countless hours of R&D testing on San Francisco Bay, which they call their unofficial test lab.
I checked in with Steve Rosenberg, via email, to learn more about basn5 sunglasses.
Can you please start us off by giving us some backstory on where the names "Tajima" and "basn5" come from, and what inspired you and Jacob to use these monikers as brand names?
Tajima is an area near Osaka, Japan where our lens factory is located. Tajima-cho is the birthplace of the modern Japanese lens-making industry well over a century ago.
The specialized lens maker I approached to create and invent our polarized lens technology brought me to Tajima, and in the time since, I've been fortunate to spend a lot of time there and come to understand and appreciate the craftsmanship that sets our particular techniques and technologies apart from anything else on the market. Therefore, the people and place are special to me.
The basn5 brand name is inspired and derived from Basin 5 in Long Beach, home to Alamitos Bay Yacht Club. A place with deep meaning for both Jacob and me. It's where I first learned to sail, 50 years ago, and where we brought Jacob for his first sail at three weeks old, on the family boat [which] we still dock in Basin 5. He learned to sail in that basin and spent his formative sailing years—and a couple of world championships—sailing out of it and ABYC.
Many of America's sailing legends, and many of the world's greatest, have launched and sailed out of Basin 5; it's the access point to some of the world's finest sailing grounds. The basin's bulkhead entrance cut is reflected in our basn5 logo design.
I've worn a lot of sunglasses in my life, but none have the same kind of optical clarity that Tajima lenses deliver. Without giving away any trade secrets, what's going on with these lenses that make everything look so crystal clear?
A lot. It's a fine mix of materials, construction, science, technology and invention, along with know-how and craftsmanship. My time as a very tactical sailor and [my] experience at Oakley, laid the foundation for the inspiration behind the invention.
I wanted the optical clarity of glass, hi mass/hi velocity impact resistance for sport use, very lightweight, and the ability to create distinct tints and light transmissions in a zero-distortion polarized lens that let great athletes tune their vision on the field of play and see the fine details that really do matter to the best sailors, fisherman, golfers, hitters - athletes.
Sounds easy, but it wasn't.
Tajima Urethane is the result of a combination of factors that's very hard for anyone else to replicate: science, technology, invention, and craftsmanship.
The lens material itself—a urethane-based recipe we invented—is unique and was ahead of its time. It gives us the optical clarity of glass, along with lightweight and better scratch-resistance [properties] than any other non-glass lens on the market.
The polarized film we use is unlike anything else available: a naked, thin film that carries everything—lens tint, polarized efficiency, and light transmission control all in one... The fabrication of all the elements into one well-constructed lens is what produces the vibrant color, sharp detail, polarized efficiency, optimized light transmission, and zero distortion in a very sharp, clear view.
We're also the only lens company in the world that can offer that exact same technology in prescription lenses. And we push it even further with complementary lens treatments that fine-tune your vision and protect the outer surface. A simple lens—but a very complicated and detailed one at its core.
As I mentioned in an email, I've long struggled with red-green color blindness, but when I wear my basn5s, I swear that I'm able to discern/separate shades of reds and greens that I otherwise can't see with my own two eyes. Are you guys achieving this with the lens itself, or with different coatings/layers, or combinations therein?
Through a combination of methods and technologies, we can create specific tints that improve on both the naked eye and other lenses on the market—filtering out and targeting certain light spectrums to deliver enhanced color, separation and detail that makes a real distinct difference.
The science behind what we've built gets complicated and proprietary (the black-box secrets): Each lens color is optimized for certain light conditions, activity or pursuit, which is why we offer very specific tints and transmission levels tuned for different environments.
The nice thing about Tajima Direct and basn5 is that we put most of this on the website in plain language—we don't bury it in technical jargon that needs an AI to translate.
We're also available to talk with customers directly, live via online chat or email, about their specific use-cases, questions or needs. Direct-to-consumer, to us, also means direct from the source.
I will also add [that] the real advantage behind Tajima Direct is the fact that anyone can now put this lens technology into their own frame of choice as a replacement or upgrade - in prescription or non-prescription. It's crazy, the people discovering Tajima Direct are blown away, most never experienced a lens of this quality and they usually associate better products with the big sunglass brands. Our customer reviews tell this story.
[Over the years, we received] requests from our customers—and a lot of top athletes—asking for a frame from us. Now they're discovering that the same kind of very high quality and technologies they receive in our lenses is now available in basn5's advanced frame line.
Seeing people discover all of this has been fun and terribly satisfying.
I'm not sure I've ever seen a pair of fancy prescription (or designer) glasses, let alone non-prescription sunglasses, that have triple hinges on each leg. What does this triple redundancy deliver that a single or even a double set of hinges can't deliver?
Structure, strength, security, power, precision. In our case, the hinge acts like the spine to strengthen the structure of the frame chassis. We developed the stacked hinge (both double and triple) —it's patent-pending—because the hinge is the most overlooked part of a sunglass frame, and the most common failure point.
At Tajima Direct, we've seen thousands of sunglasses at every stage of their life, and it's the same story over and over: within a year or two, sometimes even months, the hinges loosen, the temples go floppy, and the whole frame loses its structure, because the hinge is the connection point between the frame front and the temples. Then when it finally breaks or blows out, the whole pair gets thrown away, because it was never designed as a replaceable part.
We saw that as the opportunity. Our stacked-hinge architecture adds strength, structure, and security to the entire joint, so it stays tight and never goes floppy over time. You can feel the difference every time you open the temples—that solid, precise movement. It's actually satisfying to open and close them. We worked with an elite Austrian hinge maker to invent, develop, and build the hinge concept—both the action we wanted and how it integrates into the frame construction and material we're pioneering.
And because we've seen so many frames die from a broken hinge, we designed ours to be serviceable. If you do have an accident, the hinge can be replaced instead of the whole pair.
The frames physically feel different than other sunglasses that I've used. You mentioned in an email that the frame material that basn5 is pioneering has a certain amount of built-in flexibility, which allows the frames to mold to a user's face. How does this work? And also, if the molding is a function of body heat, what prevents the glasses from "remolding", say if they are accidentally left in a hot car? And what happens if my buddy borrows my glasses—will they return remolded?
It's one of our favorite things about this frame material and the advanced construction technology we're pioneering. The way we design and engineer the frames [allows them to] be adjustable in specific zones while staying strong and rigid everywhere else. The back ends of the temples and the temple tips are the adjustable part: hold the temple near the hinge in one hand and gently bend/flex the tips inward or outward to tune the fit around the sides and back of your head. Then, as you wear them, the material in those thinner zones settles into your head shape.
The material has a certain amount of memory retention. It always wants to slowly return to its original designed shape. Leave them sitting out with temples open for a while and they'll drift back to how they left Germany.
The [frame] material gets a bit more malleable when it's warm, which is part of why they settle into your head shape as you wear them and they warm up to your body temperature. As a rule, you never want to leave glasses or sunglasses in a hot car - excessive heat can damage lens coatings and many glasses are made of acetate (has no memory, sensitive to heat and humidity) which will warp.
So, in something like a hot car, the practical effect is that any fit adjustments you've made may relax back toward the frame's original designed shape a little faster. Since our material's memory pulls toward that designed shape, worst case is usually a few seconds re-tuning the fit. That said, leaving sunglasses in a hot car is something we would avoid for any pair of sunglasses or prescription glasses because it can be bad for lens coatings and frames, as mentioned.
And if your buddy borrows them — sure, he can tune them to his head, and they may settle into him a bit. When you get them back, just put them on and run them, or re-adjust to your preference, or leave them out and let them return to their designed shape. They'll mold back to you as you wear them.
End of the day, eyewear usually isn't a shared item—they're really a personal-use piece.
Do you have any suggestions (or online resources) for someone who is having trouble deciding which of the 14 different lens colors to choose when they are ordering a new pair of basn5 sunglasses?
Absolutely. First of all, it's important to understand personal preference should always prevail. There's no magic bullet that applies to everyone as we all see things differently with different sensitivity levels.
That said, we do offer eight signature color combinations for each of our basn5 sunglass styles, that will narrow the options down a bit.
Each lens color will also have descriptions of the tint and the front aesthetic finish on the website, as well as our recommendations for the type of conditions and environments that lens excels in.
Our main recommendation for people is to go with the lens tint they prefer to look through and the finish or color that they want for their 'look'. Our lens technology is so advanced, so pure, that any lens color is going to offer an amazingly sharp view and work well for all types of sailing, locations, or applications.
Beyond that, we're happy to help anyone select what color might be best for them, or we do have [a lot of] resources available on the basn5.com and Tajima-Direct.com websites [and blog posts] that dig into the nuance and what the best sailors like and prefer.
We also have some guides on best lens colors for other sports as well such as fly fishing, golf, etc.
Do you have any tips or suggestions for basn5 owners to keep their lenses and frames in great shape, year after year?
Rinse with freshwater after heavy (ocean) use. As sailors, we're trained early to rinse the boat and our gear well with freshwater, especially personal gear, if we want it to last—same goes for your eyewear.
We designed basn5 frames to be rinsed with fresh water and patted dry—wipe sunscreen and oils right off the frame, and we include a specific microfiber cloth pouch that doubles as a lens cleaner and storage case.
It's important to use a clean lens cloth when wiping your lenses down (any sand, salt, dirt or particles will act like fine sandpaper as you wipe your lenses). If sunscreen and skin oils are building up on lenses, bring them under warm water and a little dab of non-abrasive soap and gently swirl around with your fingers under the warm water-then pat dry and use the clean micro cloth pouch to wipe them clean.
Given the prevalence of logos and trademarks in our world, I couldn't help but notice that basn5 glasses don't have any outwards-facing branding. From a marketing perspective, what's the thinking here?
That was a very intentional decision for us. Most sunglasses are billboards — a logo on each temple, sometimes printed right on the lens.
Some people like that, some don't.
Our whole philosophy is removing what isn't necessary—no paint, no rubber, no excess decoration or branding—so what's left are the components that are necessary for the best comfort and performance in a very clean, elegant, yet understated design that should enhance the personal style of the wearer, not represent a branding statement.
Instead of a logo doing the talking, the design does.
The visible hinge in the gap between the frame front and the temple — that's our signature. One of those: "if you know, you know" situations. We think our customer, the people we design and build basn5 for, tend to appreciate that. They don't want to be a walking ad; they want a great pair of sunglasses that simply uplift their mood, vision, and personal sense of style.
Part of it is also simply our own taste. basn5 was born out of our own needs that we felt our friends and others would also like...basn5 is what we want for how we live...and we gravitate toward clean, quiet understated design that provides real, reliable and repeatable performance advantages — products that keep it simple and don't shout — and that's the design language we wanted basn5 to live in: quiet confidence.
From a marketing perspective, it's a bet that restraint is more recognizable and more desirable than a logo. So far, the people who get it love them.
If you know, you know.
Is there anything else about Tajima lenses, or basn5 sunglasses, that you'd like to tell us about or add for the record?
For us, this all started because we have lens technology that had proven to be the best in the world. Jacob had a business idea—why not make our lens technology available to everyone via lens replacement and upgrade for any frame—which became Tajima-Direct.com, that he built during his time at Stanford. Then Covid, of all things, forced us to flip the switch and turn it on.
Not only did it solve a problem and fill a white space to become a successful business, [but] Jacob and I get to create and do this together.
As businesses grow, they evolve. I never expected to get back into the frame game and build another eyewear brand. It wasn't something I had in mind or thought much about. But as Tajima Direct grew and customers and great athletes kept asking for frames, we saw another white space and the chance to create something fresh that we began contemplating. Focused on utilizing a fascinating new frame material and construction technology that would enable us the ability to create a forward-thinking sunglass line rooted in performance, with elevated design and construction. Specifically, engineered for movement, refined, and designed for the hybrid lives we live today...one pair everywhere.
Ultimately, we have a shared vision that taps our unique mix of industry knowledge and experience, with a young leader that is smart, digitally native and embraces technology. This has allowed us to develop a distinct approach with borderless perspective in a world that's changing fast—that's pretty special.