Sill Optics has introduced a thermal imaging lens with 50mm focal length and an f-number of 1.5. The S5LPJ9050 works in a wavelength range of 8-14µm. It is colour corrected for this range and works free of vignetting with IR-detectors up to an area of 18 x 18mm, the image circle thus measuring 27mm. The distortion rate is 0.25 per cent and at full image circle the image angle is +/-15°. It also works well as a macrolens at distances of 1m and above.
Because of the nearly diffraction limited resolution, the lens is also suitable for the use with 15µm pixel sensors. As it consists of only three lens elements it ensures maximum transmission. The design takes the use of a 1mm germanium window in front of the detector into account. It is available either with an M42 or a C-mount adapter.