Race proven! I put the light to the ultimate test by competing in the Gold Rush 24-hour Adventure endurance race in the Sierra Nevada mountains of California. Many of the other competitors had $500 HID lamps from NiteRider, Light & Motion, etc, yet throughout the race nearly everyone that saw my light commented as to its extreme brightness or asked where they could get one. It was that much brighter than anything else.
brightness: 500+ lumens / 7 million+ mcd @ 15 degree
weight: 120 gram headlamp + 60 gram electronics + 280 gram battery pack = 460 gram total
cost: $60 including batteries
lifetime: 3, 6, 12, 24 hours (4 brightness settings)
size: headlamp portion 5cm x 5cm x 2.5cm
rechargeable: Ni-MH or Lithium-Ion batteries (your choice)
unbreakable: LED technology
- Cyan (or Green) high power/high efficiency LED's
- high-transmittance TIR lenses
- high-efficiency DC/DC step-down converter
None of this was possible just a couple years ago, but now it can be done easily with inexpensive components you assemble yourself!
i've got several other power-LED instructables too, check those out for other notes & ideas.
This article is brought to you by MonkeyLectric and the Monkey Light bike ilght.
Step 1: What's so special here?
(1) The rods are about 2.5 times more sensitive to light than the cones. That's why they are your night vision.
(2) The rods and the cones are not equally sensitive to all colors (wavelengths) of light. The wavelength of maximum sensitivity for your rods is 507nm, or blue-green. Why? Moonlight is more bluish than sunlight. The color of maximum sensitivity for your cones is 555nm green, about the color of plants. (more info)
To get the best possible vision at night, we'd like to build a lamp that puts out the most light at the 507nm that our rods are most sensitive to. This gets us the best vision at night for the least power used. If we had a white light instead, it would take much more power to get as much visibility.
Thanks to our friend the LED, this weird pure turquose light is possible! The latest LED technology is much more efficient than a standard light bulb to begin with, but using the special turquose color gives us even much better night vision than white, and is more efficient than even the fanciest HID lights.