450nm.

[hakzaw1]

^^^ ditto
I made the MOST AMAZING and AWESOME discovery today.
I lit matches and fireworks, cut tape, popped balloons , zapped bugs, and more with a MAGNIFING GLASS and the SUN!!!! wow

 

[ApexProxy]

Meh, doing all of the above with monochromatic coherent light being emitted from a small handheld device is much more fun IMHO