An embodiment image sensor includes a pixel region spaced apart from a black level control (BLC) region by a buffer region. In an embodiment, a light shield is disposed over the BLC region and extends into the buffer region. In an embodiment, the buffer region includes an array of dummy pixels. Such embodiments effectively reduce light cross talk at the edge of the BLC region, which permits more accurate black level calibration. Thus, the image sensor is capable of producing higher quality images.