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Posted

I've got a mate that has imported a number of components to build a headlamp that gives off a blue light.

 

There are a total of 4 cyan (or green) high powered LED's.

 

20070126_011350_bluelight.jpg

 

 

 

Posted

The only problem I can see with a setup like that is that LED's give off a "flat" light, which means that you struggle to get definition on the obstacles in the path.

 

But it's sure bright enough!

 

If anyone needs instructions on my hubbies marvel of modern engineering, let me know. SLA batteries are heavy, but the light is cheap and good.
Posted

mentioning that, michH, what's happening with the "markII's"? Wink it was lekker dark when i left home this morning, and more and more street lights along ysterhout are not working every day...

Posted

 

The only problem I can see with a setup like that is that LED's give off a "flat" light' date=' which means that you struggle to get definition on the obstacles in the path.

 
[/quote']

 

I don't necessarily agree with you in this specific instance.

 

Our eye has "rods" and "cones".

These are the sensing cells in your eye that detect images. The cones

are your daylight & color vision, but they are less sensitive than

the rods. Now the part you didn't learn in school:

 

 

 

(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.

 

 

 

To get the best possible vision at night, you 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.

 

20070126_031449_swave.gif

 

 

 

Posted

Ah the Thug, but then we would have to argue about whether we need to see movement (easier out of the corner of your eye, are those cones or rods?) or shapes?

 

OK, let me stop acting like I'm all intelligent (you all know I'm blonde!), so let me speak from experience. When I was doing that 40km with D n D, I ran my homemade until the battery ran flat, then I had to run the Petzl headlamp (can't remember the model). I fell riding just with the headlamp because I couldn't make out the depth of anything. Also heard others talk about this problem with blue white light? 

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