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Safe too view the dot of lasers?

apollo248

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Is it dangerous to view the point of a high powered laser if there are no risks of hitting a reflective surface? Obviously if it happens to reflect off something it can cause permanent damage but is it safe to look at the "dot" of a 200mw green laser on a white wall from 2-3 meters away without protective glasses?

It seems like most concerns are from having accidental reflections, but can merely looking at the beam on a wall for a few seconds cause permanent damage?
 

apollo248

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I see but what exactly do they mean by dangerous, I'm assuming that means that it can lead to permanent damage so besides outdoors you really cant use a laser without glasses. has anyone actually gotten permanent damage from looking at the dot or is that just speculation?
 

Lumify

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I know a few people here have been at least partially blinded by lasers in general, but I'm not sure how each person was blinded. I saw a thread somewhere on these forums a while back where someone actually figured out a formula for the safe viewing distance of a dot of various laser powers under various circumstances. Assuming the surface isn't really reflective, the further back you are from a dot, the safer you are. If you're looking at dot 2 inches away from you, you could be taking 1/4 of that laser's power right into your eye. If you're looking at a dot 2 miles away, then you have nothing to worry about other than anyone getting hit by that beam. Keep in mind that the "safe" 5mW isn't really safe for more than the split second it takes to blink.
 

Ash

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I personally find looking at the dot of a 200mW green on a white wall extremely uncomfortable (slight eye pain + headache). Not to mention the after-stains you get on your eyes (similar to the temporary "negative" stain you get from looking at the sun) are slightly annoying. :undecided:
Just as I don't look at the sun for very long, I don't look at the dot from a 200mW green for very long.
Asthenopia
 

Lumify

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Even a 50mW green gives me a headache after a couple hours of looking at it. Green probably isn't as bad as some other wavelengths because at least you realize how bright it is. You could be killing your eyes with a blu-ray or IR and not even know it. If you got one of the new (incredibly dangerous) 445nm lasers, then you may be subject to the blue light hazard.
 

Meatball

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Part of the definition of a class IV laser, says that specular reflections become MORE of a hazard. Its not like you cross the 500mw line and then BAM!! The dot becomes damaging to look at. There are a BOAT load of factors that go into this, the laser wavelength, the optical density, the reflection spectrum of the surface being hit, and the distance the viewer is from the dot.... are a few to name.

Lots of Math.

To put it simply, Class IIIa can cause damage from a direct hit if the direct hit is sustained for longer than about .25 seconds, or longer than the eye has time to blink. And I mean damage, by ANYTHING that happens to the eye, whether un-noticeable, minor, or permanent.

Class IIIb can cause damage in LESS than a quarter of a second from a direct hit.

Class IV can cause damage from the coherent light that is reflected off a surface that is not normally very reflective... like a white wall.

The factors I mentioned earlier, such as distance from the dot, can EASILY turn a class IIIb laser into a class IV.

If you are looking at the dot of a 100mw laser from 1 decimeter away... you CAN be susceptible to damage like a class IV could give from 2 decimeters, to 15 meters away. It all depends on your setup.

This means, just be safe, use your brain, and don't think twice about something, just go the extra mile JUST IN CASE.

I would say that viewing a 200mw dot from a white wall should be safe without glasses if the distance between you and the dot is controlled, the laser has been secured and power regulated to reasonable degree, and access to the beam is controlled. But this is what I would say, feel free to go the extra two miles.

The less you can change ANY variable during a viewing situation, the better.

Be safe!

-Tyler
 

apollo248

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sounds good thanks for the help. I actually did order the 1w arctic laser as well:D. so i guess for that I'll only use with glasses unless outdoors and pointing at mountains or whatever.
 
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In my opinion, if the dot is uncomfortable to look at, you wouldn't want to look at it anyway. And if it's fine to look at then no damage will occur unless you stare (which would hurt). Nothing really too scientific, haha. I play with my high powered lasers indoors all the time, I just make sure to keep away from glossy/shiny surfaces.
 

Meatball

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May I add some more input?

Personally, I don't think that 1W lasers are good for outdoor use. The FDA hates class IIIb use outdoors, so I don't think that a class IV is a better idea yet.

Hey, I understand! Its COOL to wield a 100mw greenie outside. Its COOL to feel like you have the longest stick in the world that you can touch a mountain with. I know the feeling.

But honestly, I would not feel comfortable with a 1W beam going off into to distances that I can't see with my own eyes. If you DON'T really know where your dot is, and if you don't really know what your dot is ACTUALLY hitting, then I think there is a line that has been crossed. For instance, a MOUNTAIN could actually be someone's log cabin, camp site, or anything else. And if I have a 100mw greenie from 4 miles away, I won't feel as bad as I would if it were a 1W anything. I know I ought to feel the same for both, but outdoor use changes a bit once you pass a certain level of power.

I don't know how much experience you have with lasers, and I have a feeling that you don't really know what a WATT of laser light really means. That's ok, most people don't.

What you need to realize is that lasers need to be treated JUST like guns when you're outside. If you wouldn't aim there with a gun, don't do it with a laser. I would not take even a 22 caliber rifle and fire it at a mountain 2 miles out if I did not know where the bullet will land. I might fire a BB gun at a mountain 2 miles away if I knew EXACTLY what was between me and the mountain, and if the area were secured.

But listen, what you have in a SPYDER III NEEDS TO BE TREATED LIKE A 50 CAL MACHINE GUN. Collateral damage is not an 'if', but a 'when' instead. That beam can do blinding damage from WHO KNOWS how far. You can't know how far. That's why I STRONGLY urge you to keep the beam indoors, in a CONTROLLED environment. This is laser is a big deal. It has A LOT of power.

With great LASER power comes a GREATER amount of responsibility.

Please be safe, for all our sakes.

-Tyler
 
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apollo248

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I understand and appreciate your concern. I also understand the danger associated with a one watt laser and the repercussions of inappropriate use. I think the reference to using a gun is appropriate and I will follow it accordingly. That said I'm curious to know at what distance a 1 watt laser beam would not be harmful. The arctic has a divergence of 1.5 m so if it was pointed at something 5 miles away the dot would would expand to 25 feet roughly. But even at that spread I'm assuming it is still dangerous.
 

Codiejman

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The only circumstance i can think it to be ok to have a 1 watt laser outside would be solely for stargazing. never to point as meatball said in a place you are unsure of what it could be hitting. and then at the same time you dont need so much power to point at stars the Spider pro III in my opinion is a burning machine to be used with great caution. that and the color is amazing. and always have saftely glasses on i have a cheap ebay green laser that is so bright it irritates my eyes to look at the dot on the wall. 200 mW or even 100mW is harmfull if you were to stare at the dot at close distances.
 
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1W of collimated blue is excessive, even for burning.

And for stargazing something that bright destroys your nightvision.

Hence the use of 5 and 20mW greenies for stargazing. Nothing more.
 

Codiejman

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Yeah i guess thats realisticallytrue. The craze for these 445 diodes (arctic series laser especially) is ridiculous. not that its bad but if youre going to be completely safe with it you wont be using the laser for much right?
 
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Perhaps for some lab application, yes.

But I'd be happy with something from 50 to 200mW. Not everyone needs, or *gasp*wants 1W of blue.

Hence why I'm waiting for o-Like or Rayfoss.
 

Codiejman

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yeah thats true. my thoughts exactly the thought of that much power is scary to think about. but for 200 dollars its a steal. i think if i bought it i would have to current turned down and have the mW at no higher than 700 just around there and then it would have a nice lifetime.
 




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