WHAT DOES UNCOOLED LONG-WAVE INFRARED LENSES MEAN?

I employed a Sony FE twelve-24mm file/4 on an a7 II system converted to 665nm infrared. This is among my most loved lenses for large angle with infrared due to the fact if performs so very well and covers an extremely wide selection. You may get very hot spots with apertures scaled-down than f/8 but with extremely vast lenses similar to this you wo