Sigma began working on its new full frame Foveon image sensor back in 2018. However, the company hasn’t announced any major progress on the development of the sensor for three or four years. Now there’s been some positive news after CEO Kazuto Yamaki revealed that Sigma hopes to move to the final stage of development later this year.
What is a Foveon sensor?
The standard Bayer sensors that are in most cameras use filters over a single sensor. The sensors split the light into its red, green, and blue elements. These red, green and blue elements are then interpolated into a final image. This process is called demosaicing. However, a Foveon sensor uses three vertically stacked layers of photodiodes to detect color. This process is similar to the way that color film works. The sensor near the top captures blue light, the next captures green light, and the last sensor is for red light. The design captures all three colors at every point, so the image doesn’t need demosaicing. As a result, a Foveon sensor can produce very sharp, highly detailed images.
Sigma’s design process
Foveon sensors aren’t a new technology. However, previous designs have been smaller sensors. Sigma’s aim was to produce the first full frame Foveon sensor which is where the challenges arose. In 2022, Yamaki told the PetaPixel website that Sigma had moved from design simulations to building a prototype of the new sensor. The prototype had the same pixel size as the intended for the final sensor design. However, it was smaller and so had less pixels overall. At the time, Yamaki had also hoped that Sigma would have a full frame working sensor by the end of the year.
Setbacks and progress
After the initial optimism, Sigma suffered a number of setbacks. In 2024, Yamaki told PetaPixel that the company had experienced technical issues with the prototypes of the sensor. The CEO explained that the biggest problem was the high level of noise in the images being captured by the prototype sensors. However, finally it seems a corner has been turned. At the CP+ 2026 Show in Japan, Yamaki told PetaPixel that the company had narrowed down the causes of the technical issues. As a result, Sigma is hoping it can move to the next stage of development, a full size prototype, by the middle of this year.
What we think
Developing a new image sensor is a complex process. By working on a Foveon sensor, Sigma has given itself even greater technological challenges to overcome. Therefore, it’s not surprising that there have been setbacks and delays over the past 8 years since the project was initiated. However, Sigma seems dedicated to see the process through to the production of a final working sensor. Hopefully the company’s hard work will pay off, and we can see what benefits the full frame Foveon sensor will deliver.
