Enderman
(Enderman)
53
Uh, no, corona happens in reflector flashlights because the distance from the LED to the reflector surface varies largely.
A lens has all the refracting surface at almost the same distance from the LED.
Of course it depends on the lens F number though, but there is close to 0 corona compared to a forward-facing reflector.
Any “spill” people re talking about is simply tray light that is not collimated properly, this happens with even the best aspheric flashlights, there is always a bit of light reflecting around on the inside.