from this chart I think the only cams i'd ever consider are from 1/1.2" sensors2MP on the 1/2.8" may be the best based on distance to IDENTIFY. A 2MP varifocal optically zoomed to a distance of 80 feet with a focal length of 40mm will outperform an 8MP on a larger 1/1.2" sensor with a 2.8mm focal length at 80 feet.