650nm Laser Pointer

[Nick481]

Hey,
I'm planning on buying a 650nm(red) laser and wanted to know what the max mW a 650nm laser can be without seeing the actual beam at night. I'm in Florida, so high humidity and low elevation. I apologize if this has already been covered before, but I did search the forums.
Thanks for the help,
Nick

 

[brendon7358]

why wouldn't you want to see the beam ? And even my ebay 1mw 650 (labeled 1mw anyway) I can see the beam if I am looking at the laser.

 

[InfinitusEquitas]

Uhm... so you want a red laser where you specifically can't see the beam...........:undecided:

Stick to 1mW keychains.

 

[Sigurthr]

It depends on angle of incidence. If you are very near the axis and there is sufficient dust/particulates in the air even 1mW can be seen, but usually just barely.

I have a >200mW 650nm laser which you can't see the beam of unless it is very dusty/foggy outside, again angle of incidence matters though.

 

[Nick481]

Thanks for the replies. The angle of incidence that I don't want it to be seen from is perpendicular to the beam, and not a particularly foggy night either. My friend's 5mW green cant even be seen from perpendicular on an average night where I live.

 

[Ghostchrome]

I sense some mischief in the works... :shhh:

 

[Nick481]

Uhhhh I don't knoww what your talking about?????? hahaha.

 

[InfinitusEquitas]

Is it wrong of me to hope he points it at a cop and the cop shoots back?:eg:

Natural selection really isn't doing the job like it used to....

 

[Nick481]

I really am not going to use it on people, I just want to use it normally but not have everyone in the neighborhood seeing it.

 

[InfinitusEquitas]

If you're trying to convince us you're not looking to cause mischief with it... you're really not doing a good job.

I mean why else do you need a laser with which people specifically can't tell where it's coming from?

 

[Sigurthr]

Is it wrong of me to hope he points it at a cop and the cop shoots back?:eg:

Natural selection really isn't doing the job like it used to....

Indeed! I say we give it a helping hand every now and then. :eg:

 

[Nick481]

Its just so sad how inconsiderate some people can be. I thought I would get some friendly help from this forum but I didn't. Guess I'll just go with a 10mW red like my friend told me....

 

[Sigurthr]

We're mostly half-joking, don't get offended. We can joke around here and there, especially since we already answered seriously earlier.

You have to understand that the normal residents here on the forum have to deal with idiots wanting lasers for inappropriate reasons on a daily basis, and it's never wrong to be too careful.

If you're new and want to be trusted to be better than the riff-raff that floats through here regularly, then stick around and make that impression. People will warm up to you QUICKLY, trust me. All you have to do is show them you're not part of the problem and that you are willing to learn.

 

[InfinitusEquitas]

Instead of getting indignant why not just explain what the purpose of the laser is?

Would have been even better to just include that info in the original post.

If you come to a chemist forum and ask how to make a bomb, do you think anyone would be stupid enough to help you?

On the other hand if you needed it to blow up a tree stump, and proved that's what it was for... you would end up getting pointed in the right direction.

 

[Nick481]

I guess I should have understood that. Sorry for being so quick to jump for a conclusion. I understand that I have no credibility here and for all you guys know I could be trying to point my laser at an airplane pilot (which would be very bad). I guess since I'm new here I didn't know what your guys' nature was. I should've stated the reason I needed it; and I understand it may have sounded suspicious that I didn't want other people seeing it. The truth of the matter is that I kind of find it fascinating that I can hit a tree with a dot of light from extremely far away just from a pen sized device in my hand. But thanks for clarifying for me guys, it's better to learn about something early on so you don't get screwed later.
Thanks,
Nick

 

[InfinitusEquitas]

Glad to hear you understand.

If for now you're only interested in seeing a dot far away, a 5mW red or a 5mW green laser would work well for you. Although it is possible to see the beam of a 5mW green laser when it's dark and humid.

For the red laser, just about any cheap keychain will do to start with. For the green, go to optotronics or laserglow.

You can also pickup a AAA red laser for ~$1-2 dollars off of ebay, although shipping can take a while.