How deep can YOU see?

[awlego]

How far into the IR spectrum can you see? Or how deep into the UV spectrum? I haven't had any chance to test if I can see anything below 405nm, but I have some IR LED's and I can even see a faint red glow with 100mW of 940nm light

Just wondering what the range of other members' vision is I previously thought "normal" was 400-700nm, maybe 400-800nm, but seeing 940nm seems pretty far into the IR range to me.

 

[Meatball]

The red glow you see is not the 940nm light itself. Diode lasers are not known for their particularly narrow bandwidths in their emission.

 

[MarioMaster]

Lowest I've seen is 355nm (very dark violet halo around the dot), highest is probably 900nm (dark red) or so, random diodes from testing Heruur batches and the 355nm was a q-switched dpss unit that I later sold on ebay.

 

[davidgdg]

It is said that people who have had their lens removed (for cataracts) can see into UV, but I don't have a pure or filtered source to test it with.

 

[LRMNmeyer]

I can pretty easily see the IR coming from my tv remote in dimmer light conditions. I don't have a UV source to check the other side of the spectrum with though.

 

[Gryphon]

I tried a TV remote and i could just barely see the red light

 

[FireMyLaser]

I advise NOT to look into the remote or any other IR-source. It may be incoherent light, but it can still do damage! Might as well jam a white LED key-chain light in your eye...

 

[Gryphon]

Yeah, kinda overlooked that :yabbem:

 

[Xplorer877]

I advise NOT to look into the remote or any other IR-source. It may be incoherent light, but it can still do damage! Might as well jam a white LED key-chain light in your eye...

When I was like 12 I replaced the IR led with a 5mm red led and it was pulsed at a very low duty cycle and was not very bright at all. It was only a few mAs.

But I agree, it's not a very good idea to point it in your eye, even though it's unlikely to be very powerful and cause damage.

-Tony

 

[FireMyLaser]

When I was like 12 I replaced the IR led with a 5mm red led and it was pulsed at a very low duty cycle and was not very bright at all. It was only a few mAs.

But I agree, it's not a very good idea to point it in your eye, even though it's unlikely to be very powerful and cause damage.

-Tony

Red LEDs require higher voltage than IR LEDs, just like laser diodes. It may not have gotten enough voltage to come on fully.

 

[Uranium]

980nm

 

[Gryphon]

^ So at 981nm it ceases to be visible j/k

 

[Uranium]

Nah, I can see the glow from a 5watt 980nm led. (no i will never sell it.)

Also, 50kV x-rays. No, I never looked into an x-ray tube. When I had to get a CT scan I asked doctor to turn off the lights and he said what the hell, sure. I let my eyes dark adapt for 5 minutes, and when the scan was preformed, I saw a deep blue light seeming to come from inside the eye.

 

[millirad]

I can see Gamma rays, when I watched Spock reach into that radioactive source that killed him. Don't remember which movie that was though. Gamma rays are bright green. J/K

 

[Gryphon]

When I had to get a CT scan I asked doctor to turn off the lights and he said what the hell, sure. I let my eyes dark adapt for 5 minutes, and when the scan was preformed, I saw a deep blue light seeming to come from inside the eye.

I'll bet that was pretty cool, and a bit freaky

 

[aryntha]

Last night I did an experiment, thinking of this thread. I have the o-Like 980nm 65mW laser, and, while I can see the 808nm version just fine, I never had been able to see the 980.

I let my eyes dark adapt for about an hour, and set up some white surfaces in my closet. Well, i'll be damned - I saw it.

And it didn't look red. It looked almost *gray-green*, and more visible in my peripheral vision than in the center. So I think I actually did see 980@65mW. I was expecting a dull red but that's not what it was at all - as if the cones weren't doing it, but the rods were.

But I definitely saw it - even if I changed the focus of the head, I could see it being defocused and focused.

Very strange, and I don't think it was broad emission either, since 808 definitely appears as a dull red to me, it must have been above that.

Uranium - That story is pretty cool, do you think the blue glow was ionization?