WHAT DOES UNCOOLED LONG-WAVE INFRARED LENSES MEAN?

I made use of a Sony FE 12-24mm f/4 on an a7 II entire body transformed to 665nm infrared. This is one of my preferred lenses for extensive angle with infrared for the reason that if performs so properly and handles an ultra wide range. You may get sizzling places with apertures smaller sized than file/8 but with ultra large lenses similar to this