5mW lasers, used against a posterboard backstop, while I'm careful to contain reflections--no problems. I practiced the layout and my motions to make sure.
When you buy a laser, check it. The labels all said < 5mW, but the green laser was easily 10x as bright as the one I already had. That isn't safe for use around kids, and is stored safely away, without batteries. I need to make my own label for it.
I hate to imagine some poor cat running into the beam. They blink fast, but even so...
How did I know how bright it was, since I don't have a power meter? I already a green laser and knew the new one was brighter, and when I shone the spot on a slanted surface (non-reflective!) the image spread over 10x the area was still brighter than the old laser, though comparable. But if I didn't already have something to compare it with, I could look at the beam spot projected on the wall for a moment. If the afterimage lasts more than a few seconds, it's dangerously bright. With a 1W laser, just looking at the image on the wall can cause permanent damage to your eyes--the powerful ones aren't toys.
5 comments:
Thanks
Way back in 2008/9 a unit I was with in Iraq had a commander (or deputy commander, or XO -- details blur) who was colorblind. Because green wavelengths are much shorter, the green lasers are always more intense than the red ones. He couldn't distinguish either color, but he could distinguish the dot of the green laser more clearly. As a consequence, the unit invested in a lot of green lasers so that everyone who had to make a presentation to the command staff could point a laser at the display.
Iraq also sometimes has intense dust storms.
Somewhere there is a picture of me and my comrades, outside in a dust storm, all apparently armed with green lightsabers. It was just the kind of foolishness you get up to with all that time to kill -- long periods of boredom punctuated with short periods of excitement, or however that quote goes.
Your eye's sensitivity peaks in the green, so for the same intensity the green will look brighter.
Creativity is a good thing. I should ask if they do that exercise at the Pole too...
In a field hospital during World War I, a soldier named Tolkien developed the idea for an epic cycle.
Well, that was a better use of the time than mine.
Post a Comment