Qualcomm Clear Sight dual camera technology is powered by Qualcomm Spectra ISP and is designed to give photos improved DR, sharpness, and less noise in low light. The two camera lenses have identical focal length (meaning they see the same distance). But each camera has a different image sensor: one color image sensor, and a separate black and white image sensor (which can absorb more light).
The B&W sensor is unable to capture color, but its ability to capture light increases by 3x, helpful with low-light environments. Without the color filter, these black and white photos have much better contrast, and in low light have less noise and improved sharpness.
Clear Sight technology is supported by the Snapdragon 820 and 821 processors featuring Spectra ISPs. Clear Sight consists of a single, fully integrated hardware module that contains two cameras, plus computational low light imaging algorithms that enable Qualcomm Spectra ISPs, designed to take photos at the exact same time and merge the two photos together, instantaneously, with good image quality even in low lighting.