at 25m can clearly see child face and child image can be 1/2 for full image high, at 75m 1.5m high person image is about 1/3 for full image high, 1.65m and 1.75m high person image is bigger than 1.5m high person, also can see the image is clear and sharp that can compete with many 640x480 chip detector thermal sight ( thermal weapon sight ).