An image sensor generates an image signal with a differential response to image light. The image sensor has an array of photosites divided into standard photosites and non-standard photosites. A limiter provides the standard photosites with a predetermined standard response to a light exposure and the non-standard photosites with a predetermined slower response to the same light exposure. The standard photosites and nonstandard photosites both sparsely sample the array in a predetermined pattern.