13-04-2012, 05:56 PM
This is being discussed over at UKVRRR, and the question of polarised light was suggested, but LEDs don't emit polarised light. UV was my favourite, but a member there is fairly convinced it's not that.
However, if the numbers were etched, that might be clue. The very intense light from an LED torch, light which has a peculiarly spectrum as well, could easily show up if there are minute physical disturbances to the surface of the glass...
However, if the numbers were etched, that might be clue. The very intense light from an LED torch, light which has a peculiarly spectrum as well, could easily show up if there are minute physical disturbances to the surface of the glass...
