Introduce CMOS pixel array into dark environment and acquiring video image frames. During a first frame, reset each row of pixels sequentially, and one row at a time, and then read each row of pixels sequentially, and one row at a time. During a second frame, reset each row of pixels sequentially, and one row at a time, and then read each row of pixels sequentially, and one row at a time. Control a light source to illuminate the dark environment during at least a portion of a vertical blanking period between the reading of the last row during the first frame and the reading of the first row during the second frame. Control the light source to not illuminate the dark environment: (a) between the reading the first and last rows during the first frame and (b) between the reading the first and last rows during the second frame.