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noob question

verybigkitty

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<NEWB QUESTION>
What are the effects of IR? Like why is it bad if a laser doesn't have an IR filter?
</NEWB QUESTION>

I searched some, but the term "IR" has way too many results to go through. Thanks.
 



Aseras

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IR is infrared light. It's effect is just like any other light. Depending on the material being illuminated more or less energy will be absorbed or reflected.

If a dpss laser doesn't have an IR filter, then IR will "leak" and be mixed with the visible light output. IR is generally considered to be invisible, although in low light conditions you can barely see near-infrared, the lower end of the IR spectrum.

Leaking IR is generally just a deceptive way of making a cheap laser seem to have a much greater output. a laser with a good IR filter will output say 50mw of green. Without a filter that laser will still output ~50mw of green, along with a few mw of IR, usually less than a few percent. That small amount of IR when measured with the green output on a typical silicon based ( a solar cell ) laser power meter like the lasercheck will read the output as perhaps 75mw or even over 100mw. Many if not most of the 200mw or 240mw or similar laser pointer you will find on ebay are doing this.

The danger is perhaps that you can reflect the IR light that's virtually invisible and not realize you are being exposed to it. The catch is the IR is very divergent ( it spreads out much greater than the green beam ) so it appears to be emitted like a "cone" of IR around the green dot. The good news is that by the time the ir has spread enough from the green that you could reflect it and not the green, it's probably spread enough to no longer be a danger to your eyes.
 

verybigkitty

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So it doesn't like destroy your brain, or kill sperm or something? rofl

edit: forgot to say thanks. Very informative post. =]
 

Hemlock_Mike

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Kitty --

I think Aseras has summed up what many of us feel. IR at CLOSE RANGE can be bad for LIKE your eyes, but not LIKE bad for your sperm ( don't point it there). There are many reviews on this forum SO, LIKE you need to read them and make your own mind up.
Basically -- don't put your nose up to the balloon you are going to pop. Most of the IR will diffuse and keep exposure short.

Mike
 

verybigkitty

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Hemlock Mike said:
Kitty --

I think Aseras has summed up what many of us feel.  IR at CLOSE RANGE can be bad for LIKE your eyes, but not LIKE bad for your sperm ( don't point it there).  There are many reviews on this forum SO, LIKE you need to read them and make your own mind up.
Basically -- don't put your nose up to the balloon you are going to pop.  Most of the IR will diffuse and keep exposure short.

Mike
yea, thanks or whatever, but you don't have to be a douche about it. Just becuase somebody says "like" to express something, you don't have to go and do that. so LIKE, stfu

ps: Thanks for the info
 

AJ_Dual

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The biggest worry is that your eye can cook in a small place like an egg.

We've all seen how clear egg whites turn white and opaque when cooked.

If your "lucky", the laser light just gets focused on the retina, and you lose just a patch of your vision. If you're unlucky, the proteins that comprise the clear parts of your eye are like those egg whites. A laser powerful enough to light matches, cut tape etc. is powerful enough to denature the proteins of your eye, and blind yourself.

As others have said, the IR that's leaking from a cheap green DPSS laser is rarely focused well, and not usually very collimated either. Other than being coherent, the IR light is more like an IR LED flashlight. Generally, the point of maximum IR danger would be right near the aperture, where the green light would warn your eye away from staring into it anyway. (Or cook your eye anyway)

The problem is that since you can't see the IR, you don't KNOW that for absolute certain.

To really know the danger from an IR leaky green, I'd guess the best way would be to use a laser meter, measure the total milliwattage, then repeat the test with an IR filter so you know how much of the total was the IR, then look at the beam pattern from known distances with an IR sensitive camera (ideally with a green filter to prevent the camera from being blinded by the green spot), to see if you can determine it's focus point (if any) and divergence of the IR light.
 

Hemlock_Mike

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I built an IR "pointer last week.  247 mW of 808 nM.  I received my UVEX goggles a couple days ago.  Without the glasses, I can see a dim deep red spot and I keep it away from my face.  With the glasses, I see nothing so it's difficult to aim.
Ae greenie output is so bright, you can't see the IR.  An IR pass filter will let you view its diffused beam using a digital camera.  Best to use a meter or ask if someone has measured theirs.

Mike

OH-- I forgot--- stfu ???  some thanks for understanding ???
 

gmAg21

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verybigkitty said:
So it doesn't like destroy your brain, or kill sperm or something? rofl

edit: forgot to say thanks. Very informative post. =]
 

RobTheVIP

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LOL!! KEEP IR LASER AWAY FROM ANGRY WIFE!

It is mainly just dangerous to your eyes. :eek:
 

Cyparagon

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*Laser pointer forums does not encourage the use of cheap lasers as contraceptives.
 




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