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Strength required to see green beam at night

robertkoa

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Was thinking of getting a green laser to play around with carefully and legally , of course, and noticed one on Ebay, claiming to be "military" grade uses the lithium battery, but says only 5 milliwatts.

Guessing that since it says you can "see" the actual beam, it's really more powerful- it's only $19.95 with the charger- it's not a pen type but a small barrel type but not one with a key lock etc.

Does anyone have any info on these and could it actually be powerful enough to "see" the beam for a FEW MILES as claimed ?

Thanks.

http://www.wedowholesale.com/ebay2/lasertorchsesdjfadsjiorejgdfgfdg.jpg here's the image- as you can see it's not the "pen" type and uses the rechargeable Lithium battery.

http://www.ebay.com/itm/330606104842?ssPageName+STRK;MEWAX;IT&_trksid=p3984.m1423.l2 ebay link includes battery and charger for 20 bucks- good deal ?
 
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weeba2kv

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link please , and if it sais <5 mW that means atleast 5 mW , 532 green will be visible after 20 mW @ night :)
 

ARG

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5mW pens are usually over spec, and you can see the beam at night.
 

Ra1nfade

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link please , and if it sais <5 mW that means atleast 5 mW , 532 green will be visible after 20 mW @ night :)

I have a laserglow 4.3mW 532 and its beam is readily visible at night. ;)

<5 mW means that it is no more than 5mW not at least.
 
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TuhOz

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In the main picture it says ~ 10mW
So it should be pretty visible.

But, be careful if you don't have goggles.
 

robertkoa

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You guys think even if I got Laserer to make a 10 milliwatt green ( verified NON overspec ) with an IR filter-I'd still need goggles with it for in home use ?
 
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TuhOz

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You guys think even if I got Laserer to make a 10 milliwatt green ( verified NON overspec ) with an IR filter-I'd still need goggles with it for in home use ?

In my opinion, no, if you dont use it in places that has mirror(s) or shiny surfaces.
 

Isoleucine

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You guys are not being very clear on this subject.
After typing up a load of information, Im rather tired, I can tell you a bit about stuff.

The beam that you see in air is due to Rayleigh Scattering. It is possible to use mathematical equations to calculate the intensity of light. The equation is:

http://upload.wikimedia.org/math/b/e/8/be8d955b92a1ebd2f85c111819788c2e.png

If you are SERIOUS about this, you can apply your constants into the equation.

But in reality under ideal conditions of ZERO luminosity and brightness, applying 532nm and five milliwatts, we can calculate that it is VISIBLE enough to be seen.
 

jost4318

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dont buy a laser off of ebay use something like rayfoss.com or get a wicked lasers core (BTW its their only model thats not backordered and I would not recommend anything but that from them) but you can usually start to see a green laser's beam between 4-6 mW at night depending on weather conditions and the amount of light pollution
 
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robertkoa

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Thanks Guys- my intention here is to have as first Laser a 5 to 10 Milliwatt Green- as I say I'll probably want to get a measured one like from Laserer which also has LOW IR ( measured ) so:

I'll be able to see it at night including beam BUT be able to play around inside - no mirrors- and use with no one else around inside without goggles, to enjoy the show more.

I would think low power oranges and yellow oranges would be good for this also- high visibility with low power.
 

jost4318

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yeah i hear laserer is a good chice as well and i heard that theyre greenies are often overspec. :)
 




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