Another random q (light wavelength)
 

I'm trying to get hold of some LEDs that will be more or less borderline visible to the human eye, but I can't remember the wavelength of visible light :(

Someone remind me please, what wavelengths can the average human eye see?

The LEDs I'm looking at have a wavelength of 405nm.

Cheers folks ;)

Roughly 400 -700 nm. Best sensitivity is considered about 550nm. Some people can see a bit outside those ranges, usually higher rather than lower.

What you making? I'm curious...

Which threshold are you looking for? the red end (long wavelength) or the blue/violet end (the short wavelength)?

405nm should be visible as a purple colour, but its right on the edge of what we humans can see!

What ya making baph? can we have a go?

Matt

Hmmm, so ideally I want just below 400nm then. Also, the lower the better. Thanks ;)

As to what I'm making, yes, it's a mod for the bike. I've been talking to another .org member about UV lighting (those at Soho last friday will probably be aware of this).

High power UV leds somewhere like the air intakes on a pointy, looking forward. The theory is that white (ie road markings) turn a slightly different colour under UV light, so it might be possible to see road markings ahead of standard lights (depending on the power & spread of the LEDs).

I've found a couple of pre-made units, which are completely weatherproofed, and cheap enough to try that if it doesn't work, I can throw away.

Why do I want it invisible to the human eye? Well, it's either RTA or Construction & Use that says the only visible light allowed at the front of a vehicle is white, indicators, or comes with a siren. If the light itsn't visible to the human eye, whilst possibly illegal (I need to confirm this too), I doubt I'll be stopped over it.

Like I said, the theory might not work, but for the price I've seen these pre-made LED clusters, it's worth a shot.

Thanks again for the specifics of visible light, and I shall keep all those interested up to date :)

Thats a pretty interesting idea..

...good luck!

Matt

"the range of UV wavelengths is often subdivided into UVA (400–315 nm), also called Long Wave or "blacklight"; UVB (315–280 nm), also called Medium Wave; and UVC (< 280 nm), also called Short Wave"

Courtesy of Wikipedia...

...that'll be so dogs can see you coming.........or have I got something wrong there? :?



:wink:

Personaly id have a couple of IR floods along side a HD IR camera with HUD built into the visor with the feed from the camera. Just like they said they where going to offer as an option on the New S-Class...i think that Clarkson called in Collievison!

Then we'll all just say they are copying Rictus' SV

Dan

So.... is it really the case that LEDs are so powerful now that they may be able to reach forward more than your incandescent headlights?

Interesting. How far are we off from using LED as headlights?

Has anyone a site with specifics on the latest and greatest LEDs in comparison to legacy bulbs ?

Danke Schon!