Always on the lookout for new lenses that might apply to infrared, I came across the UV-VIS-IR 60mm f/4 APO Macro from Coastal Optics. Its performance specifications look absolutely stunning, offering best-in-class MTF along with apochromatic performance from 315nm to 1100nm (ultraviolet all the way through longer-wave infrared). It actually transmits from 290 to 1500nm, highly unusual to say the least.
Incorporating an unprecedented five (5) fluorite elements, it’s truly an exotic lens. (Ultraviolet transmission requires quartz or fluorite elements; normal glass attenuates ultraviolet). It seems probable that performance for visible light photography will also be stellar and for those looking to shoot ultraviolet and never obtaining the rare 105mm UV-Nikkor, this might well be the ideal lens. The fact that it is apochromatic deep into the infrared band is a huge plus for infrared shooters as well. The only real downsides seem to be price (likely to be in the US$4000-5000 range), and the f/4 maximum aperture. I should receive an evaluation sample of the 60mm sometime in December, and I will report on it here as I’ve done with the Zeiss ZF prototype lenses for infrared.
Coastal optics also offers the 105mm f/4.5 UV-Micro-APO lens, but it is apochromatic from “only” 250nm to 650nm, not really suitable for infrared use as it attenuates infrared fairly rapidly beyond 650nm (according to Coastal Optics).
There are also two circular fisheye lenses, the 4.88mm offering a 14.9mm circular image and the eight (8) pound 7.45mm offering a 22mm circular image. The price might make you faint, but the performance appears to be state of the art.