Sigma Interview CP+ 2025: Engineering as Art, the new Sigma BF and 300-600mm Super-tele Zoom
posted Sunday, April 13, 2025 at 11:13 PM EDT
I was in Japan recently for the annual CP+ photo trade show and conference in Yokohama and was also fortunate to catch Sigma's press event the Monday before. The timing was good, as I got to sit down with Sigma's CEO Kazuto Yamaki during the show to discuss some of what they'd just announced. He's easily the best interview in the photo industry, thanks to his deep understanding of both business and technical aspects of Sigma's business, not to mention his unusual frankness.
The big news this time was the new Sigma BF camera body, an extraordinary 300-600mm f/4 super-tele zoom lens and an all-new 16-300mm superzoom lens for APS-C bodies. It's particularly interesting in that the release of the Sigma BF body in some ways marks a recommitment to Sigma's core strength of producing exceptional quality and functionality for the price to photographers of all stripes. As Yamaki-san himself said it at their press conference, "... excelling at the art of engineering, engineering for art."
Read on for all the details from my latest conversation with Yamaki-san:
You spoke at the start of the press conference about your struggle to find a direction for Sigma into the future, and settled on the idea of being a "best of the best" company, with engineering and art intertwined. You've been focused on producing high-end, world-class lenses for quite a while now; the decision to go higher-end was one that you and your father took before his passing. How is this new direction different?
When we launched the first Art lens in 2012, I had no concerns or worries about the future. I was really convinced that we should make the best products. As long as we made the best products, we would be okay because customers support us. But starting five to six years ago, the smartphone image quality had become really good. In some cases, it works better than conventional dedicated cameras because they use sensor stacking technology and computational photography.
I remember watching some YouTube content where reviewers said, "We don't need a dedicated camera anymore. The phone is enough." I became concerned whether we could survive just doing the business of supplying camera lenses. Some people suggested we make lenses for smartphones or for automobiles because the photo industry may not be sustainable.
I was thinking about this for many years, and eventually I became convinced that there will always be photo enthusiasts, photographers, and camera enthusiasts. They're still looking for even slightly better quality products, and they'll never disappear. So I became convinced again that we should focus on product and technology. It's not that our direction is so different than what we were thinking 12 years ago, but I went through a period of questioning and looking at other markets before deciding this is really what we should do.
Now for something completely different: The Sigma BF's user interface
The Sigma BF camera is quite striking and takes a very different direction than many cameras. How long was it in development?
Yamaki-san: We started the project about three years ago. The main reason it took so long was because we changed the processor chip between the Sigma fp and the BF. If I remember correctly, we had to use a different OS, so it took a long time for our software team to develop the firmware for the BF. That was the bottleneck on the project.
The BF's UI is very unique, unlike any I've seen to date. Was that in development for longer? I'm curious about the development process.
The fp also has a unique user interface, different from others. We've been discussing internally what the UI for digital photography should be for a long time. For example, we were always skeptical about the mode dial. Mode dials existed for film cameras because at the time of film, you couldn't choose ISO sensitivity and color – it always depended on the film you chose. All you could do on the camera body was control shutter speed and aperture.
But when it comes to digital, you can choose shutter speed, aperture, ISO sensitivity, and color. These should be treated equally, but because most digital cameras inherited the film camera system, the mode dial is still at the top of the UI hierarchy. You've got shutter speed and aperture up at the top level, and then down in the menu, you've got color options.
We've been discussing internally that at some point we should reconfigure the menu system from scratch and optimize it for digital photography. Also, from the beginning, we were convinced that we should make a very simple camera for daily use – easy to use and enjoyable. But if we use the existing menu system while reducing the number of buttons and dials, it becomes harder, not more intuitive. So we had to reconfigure the menu system to optimize for fewer buttons and dials.
How did you prototype the UI? Did you make a working prototype based on an existing camera to see how the UI felt while shooting?
In the beginning, we made a mockup – just an aluminum block that doesn't work. We discussed the UI concepts on the computer screen. Our UI designer created digital mockups, and then we could imagine how it would work in shooting environments.
To be honest, I was not 100% convinced that it would work very well, but I pushed the UI engineer to make radical changes. I trust him quite well. It takes a lot of courage, but I felt we should optimize for this camera specifically.
I appreciate the concept of the UI. One of the biggest obstacles to me personally taking pictures is that focusing on the camera takes me out of the moment. Is that some of what the BF is about?
I just wanted to create a camera that people want to take out most of the time. As long as you have a smartphone, you can take some decent photos, but still, people are interested in cameras. They want to bring out their camera as much as possible – to restaurants, bars, museums. Sometimes we regret that we only brought the phone.
Whenever you have some time – for example, if your flight is in the afternoon and you have one or two hours in the morning – you might want to walk around the hotel. If you have a camera with you, you'll try to find nice places to take pictures. Once you start taking pictures, you’ll feel you can enjoy the experience, and those one or two hours become quite enjoyable. That's the kind of experience I wanted to create with the BF.
This is my personal opinion, but I don't think a smartphone can motivate us that way. If you have a camera in your hands, you think, "Maybe I should try to find a nice place, maybe take pictures in London, and share with friends." The fact that the BF is so stylish makes it easier to bring along anywhere – it's almost a fashion accessory that makes you want to pick it up.
Storage in the BF is a topic of discussion online, with no card slot and 230 GB of storage built in. What has Sigma heard from users about this, and what is the download speed over the USB-C connection?
I haven't heard a response from customers fully yet, but as far as I know, people accept and prefer the built-in storage because new customers are accustomed to using phones that have built-in storage. The download speed is quite fast – it uses USB 3.2 with 10 gigabit per second transfer rates.
Some people commenting online say they must have their SD cards, but others point out that SD cards can go bad, downloading from them is slow, and sometimes you forget to put a card in. For a video user, 230 GB might be small, but for a stills camera, that's a lot of storage.
Is the Sigma BF sustainable at its price?
I was astonished to hear that it takes 7 hours of machining for each body! How many can you make daily, and are you running multiple shifts?
We're running 24 hours a day. The machining idea actually came from our product designer, who wanted to make a solid body. Our engineers initially opposed this, saying it wouldn't be possible because it would take too long. But after hearing their concerns, I thought maybe we could connect multiple machining centers with robots to run 24 hours without the cost of operators.
I asked our factory manager to contact the machine company to customize a system for us. The company we worked with, used their latest machining centers, customized them slightly, and built a system for us. The total machining time is seven hours per body, but the time between bodies coming off the production line is much shorter, because there are many at various stages at once.
Currently, we can make around 200-400 bodies per month. Based on the exciting response from customers, we may need to build another production line system.
At that rate, I'm surprised you can sell them for $1,999. Are the economics sustainable?
It's actually costly in terms of both machine time and labor. The body is machined from a solid aluminum block, which means we have a very narrow opening to insert components during assembly. This makes assembly work more difficult and time-consuming compared to a design with an open body where components could be easily inserted and then covered. So the BF is expensive both for machining and for the labor involved in assembly.
[Ed. note: This was an unexpected answer. I’d been thinking in the context of auto manufacturing, where Tesla’s use of Gigapresses has cut assembly labor by eliminating hundreds of separate parts. With cameras though, the single-piece body makes it much harder to insert and attach parts.]
The astonishing The Sigma 300-600mm F4 DG OS | Sports super-tele zoom
The Sigma 300-600mm F4 DG OS | Sports lens is an astonishing, "breakthrough" lens; it's the first product intro where I've heard gasps and scattered applause from the audience. Was the development cycle longer than a typical tele zoom?
Yes, it required a longer development cycle because it was quite challenging to make it similar in size to a 600mm f/4 prime lens while reducing the weight but keeping it robust and maintaining good optical quality. If I remember correctly, our mechanical engineers had to revise the structure twice.
Our design process starts with CAD, then we make a prototype with machined parts. For this lens, after the first design was completed, we held a design review meeting where the team presented their design and all senior engineers gave their opinions. The first design did not pass this review, so they revised it. Even after building a physical prototype of the second design, it still didn't pass to the next stage, and our team had to change the design again.
I spoke with the lead optical engineer who said the initial starting point was the size, because they wanted it and its case to fit within airline carry-on limits. What optical and mechanical tricks did they have to use to achieve this?
As far as I know, there was no single magic trick or factor. It's an accumulation of small optimizations and careful design choices to make it as small and light as possible. We did use a lot of FLD glass, which helps reduce the number of elements needed, though FLD is very expensive to buy and also expensive to polish because it's very soft and easy to scratch.
The polishing process is particularly delicate – if we polish too fast, it creates uneven pressure inside the glass, and when we put it in an ultrasonic cleaning machine, it can develop tiny defects that look like scratches. So we have to use light pressure and low speed during polishing, which makes the process take longer.
The lens is about 25% heavier than the 600mm f/4 primes from the three big manufacturers. What sort of feedback have you received from early users?
As far as I've heard, photographers are very happy with the weight. They can manage it, even though it's not light. The benefit of having additional focal lengths or wider focal lengths outweighs the drawback of the extra weight. It's a whole lot lighter than carrying both a 600mm and a 300mm prime lens.
One wildlife photographer I know, who graduated from the same school as me, stays in the middle of forests for weeks at a time. For him, having to bring two or three lenses would be too heavy, especially when he already has to carry food, a tent, and other equipment.
For motorsports photographers who travel worldwide, this lens is particularly valuable. In
Europe, the distance between shooting positions and the circuit is closer, so they can use a 70-200mm or at most a 400mm. But in the US, the distances are longer, requiring 600mm. Having this zoom range lets them cover both scenarios with a single lens, which is crucial when traveling by air between events.
I was impressed by an employee displaying his setup for astrophotography using the lens. Do you see astrophotography as a significant potential market?
It's becoming a big market. At the time of film, astrophotography was very specialized, but because of the very high performance of current digital cameras, we're seeing many more astrophotographers today. Even casual travelers are becoming interested in astrophotography, especially for northern lights. They go to Iceland, Finland, or Alaska specifically to photograph auroras.
An all-new, ultra-wide superzoom, the Sigma 16-300mm F3.5-6.7 DC OS | Contemporary
The new Sigma 16-300mm F3.5-6.7 DC OS | Contemporary is the superzoom with both the widest focal length and the longest ratio. I was surprised by how light it is. Is it based on your earlier Sigma 18-300mm F3.6-6.3 DC MACRO OS HSM lens, or is it a completely new design?
It's a completely new design, built from the ground up.
[An easy question with a very short answer, but I couldn't post this article without somewhere mentioning the new 16-300mm zoom lens. It's one of the most compact, best-feeling superzooms I've handled, a perfect "vacation lens" with better than vacation-lens specs.]
Summary and Thoughts
It was interesting to hear Yamaki-san talk about his passing uncertainty about Sigma's future place in the world and that he ultimately resolved it by looking back to the decision he and his father took more than a decade ago with the introduction of their first Art series lens. I agree with him that there'll always be a place for a company so dedicated to bringing the "art of engineering" to the art of photography.
I think it's revealing that Sigma looked so deeply at the fundamentals of digital camera operation in coming up with the user interface design for their Sigma BF body. It made two things clear to me: 1) How hard Sigma works to truly understand the needs of photographers, and 2) How much trust Yamaki-san places in his designers. The BF's UI design came from his UI designer, and Yamaki-san gave him free rein to do whatever he truly felt was right. In similar fashion, he went the extra mile (or 1.6 kilometers) to see if it would be possible to realize the BF designer's vision of a monobloc body, to avoid seams and visible fasteners on the camera's body. Making it a reality involved having their machinery supplier design a complete custom solution for them with multiple machining centeres and robots to move parts from one to another. That's almost certainly millions of dollars of investment in pursuit of a designer's dream.
Sigma has a long history now of creating lenses that reset expectations about what's possible, especially at the prices they manage to deliver them at, and the new 300-600mm F4 DG OS | Sports lens is the latest example. It makes super-tele photography more affordable than ever before, with a price half that of competing 600mm f/4 primes and only 25% heavier. Even for people who can afford the primes, having effectively three super-teles in your bag for just 25% more weight than one of them is a huge advantage, worth multiples of the price.
Finally there's the 16-300mm F3.5-6.7 DC OS | Contemporary, which got short treatment in this piece but nonetheless looks like a great new lens. Doing quality engineering to a price point has long been a Sigma hallmark, and the 16-300mm is compact, looks good and feels great in the hand.
As always, it's a pure pleasure to interview Yamaki-san. Besides being unusually candid and open, as the head of his company, he doesn't have to look over his shoulder to worry about what some higher-up might think of what he has to say. On a daily basis, he works directly on the engineering floor(s) of Sigma's headquarters building, and travels almost weekly to their factory in Aizuwakamatsu, Japan to meet with the manufacturing engineers there. I look forward to my next chance to meet with and interview him, whenever that might be. Stay tuned... :-)
(What do you think? I'll watch the comments below for a while after posting this, I'd love to hear your thoughts and will be happy to answer any questions I might be able to.)