The STAR-250 is a 0.26-megapixel monochrome CMOS image sensor manufactured by On Semi (Cypress). It delivers a 512 × 512 pixel array with a 25 µm pixel pitch, providing efficient photon collection at each photosite. The optical format spans a 18.102 mm diagonal with a 0.042361111 aspect ratio, corresponding to the 1-inch optical class used in industrial and broadcast cameras. With 25 µm pixels, the sensor features large pixels optimised for high sensitivity and dynamic range in low-light and scientific applications.