Pre-calibrated lenses are precisely engineered germanium optics available for Fluke IR cameras with 320 x 240 and under resolution. While 25 micron macro lens can identify defects that might otherwise be too small to see on such targets as PCBs, 4x telephoto lens provides 4X magnified view of target at distance to enable inspection of such targets as high electrical line or tall flare stack. LaserSharp® Auto Focus button can set focus at optimal distance for lens.