Recently there has been no obvious increase in the pixel numbers in the interchangeable lens DSC markets. This could be that the pixel resolution has already reached its optimum quality for practical use or customers have understood the disadvantage of high resolution. The optical specification of a DSC decides the total sensing area of an image sensor; in a case of the same image size, if the pixel number becomes larger, each pixel size becomes smaller. The performance of imaging systems must continuously improve as the FHD standard evolves to a UHD standard and new requirements for image sensor performance, coupled with pixel resolution, evolve.