The Sigma DP Quattro is a strange looking little camera but underneath its odd appearance there’s an extremely serious sensor at the heart. In a recent interview with Imaging Resource Sigma CEO Kazuto Yamaki revealed the Quattro’s underlying Foveon sensor could out-resolve a conventional 36MP chips similar to the those in the Sony A7r and Nikon D800E.
Yamaki showed a resolution-chart to show how much higher-resolution Sigma’s sensor is compared to a Bayer patterned sensor chip cameras are usually made with. Neither of the sensors were equipped with a low-pass filter and we can see that the Quattro can resolve cleaner lines with virtually no moiré compared to the conventional sensor. While we hardly ever look to resolution charts to test sensors, it seems like there’s something to the Foveon technology that lets it resolve even more detail.
Along with the moiré, there’s also a fair bit of color aliasing. While normally photographers will never run into this issue unless they’re shooting really tight wires it may be more subdued because of the color filter arrangement of the Foveon sensors. The new Quattro Foveon sensors are equipped with stacked color filters starting with a small blue panel that a then larger green filter envelops followed by an even larger encompassing a red filter. Bayer sensors on the other hand are fitted with an overlying array of microscopic color filters in a square red, blue, and green pattern.
While it seems that the stacking filter pattern helps reduce color aliasing and moiré, in our experience Foveon sensor have create oddly tinted images. But perhaps this new technology can render a more accurate color spaces as well as resolution.