The UV issue clicked for me one evening while bow hunting. It wasn’t hot but wasn’t particularly chilly. I was wearing an older, faded long sleeve cotton tee that was probably some variation of hardwoods timber. Lots of grey at one time had faded to almost white. I was in a climber on a pine tree just off the plot edge up about 30 feet. I’d had a little four point in the field for close to an hour and a half, feeding up and down the plot. I’m t had been under me twice already. As the sun went down the moon was high and bright. As the last of legal light faded that deer picked its head up and marched almost a hundred yards down the field to the base of my tree, looked up, and started stomping. It was then that I realized my shirt was glowing like a dim bulb. All that light grey had a glowing blueish tint.