Zeiss DTI 6/40 Thermal Imaging CameraThe DTI 6 40 Thermal Imaging Camera have a 40mm f 1. 0 lens that provides a thermal detection range of 2,180 yards and a field of view of 570' at 1,000 yards. That's a 11 x 8. 2 angular view (horizontal x vertical). Need more field of view and less range? You could get the DTI 6 20 or just purchase the 20mm f 1. 0 lens as well and exchange them as the need arises. With the 20mm lens, you get half the range and double the field of view. With the DTI 6