How visible is red laser beam to you>?

[Kohaku]

I was wondering because I can barely see my 660nm 200mw red laser at night. Is it underpowered or something or is this normal

 

[udanis]

Not too bright compared to green's of the same power.....you really need an lpm to be sure.....brightness (unless compared to another laser of a measured out put) is really hard to do.

 

[aryntha]

Due to differences not only in perceptual brightness curves, but also in Raman scattering, 660nm red beams just aren't going to be that visible.

I've seen 30mW 632nm HeNe beams that are brighter in appearance than 660nm at 200mW.

It's probably not underpowered - it's just the nature of red, the atmosphere, and the human eye.

If you really want to see a beam at night, get a green. Even 100mW will do.

 

[magonegro]

Raman scattering? Do you mean Rayleigh scattering?

Due to differences not only in perceptual brightness curves, but also in Raman scattering, 660nm red beams just aren't going to be that visible.

 

[aryntha]

Yes, sorry, that's right. Though I wasn't on another planet - Rayleigh scattering is involved in Raman spectroscopy (as is Raman scattering) - but the visible effect through the atmosphere is Rayleigh scattering, you're right.

 

[millirad]

^ +1 to both of you gentlemen for illuminating me and the OP, about the effects of Rayleigh/Raman scattering with 660nm, giving it an even dimmer appearance. Impressive!

 

[IsaacT]

I think the atmosphere definitely does affect it quite a bit. At times where the lighting is the same and the charge on my 200mW red is the same, some nights I have a much more visible beam and some nights I cannot see it at all.

 

[Boosted98gsx]

Hell, even a 15mw green has a visible beam (at night).

 

[magonegro]

Sometimes atmosphere seems the same tranparency but relative humidity and/or micro-dust definitely affects beam visibility, but don't make mistake, this affects *almost* by equal every wavelength, not only 650nm.

I think the atmosphere definitely does affect it quite a bit. At times where the lighting is the same and the charge on my 200mW red is the same, some nights I have a much more visible beam and some nights I cannot see it at all.

 

[midias]

Just the nature of the beast I have a 660nm that I measured at ~200mw and it is not as visible at night as a 25mw 532nm

 

[blrock]

That's my 500mw 635nm laser.. Beam is extremely visible outside.

 

[jedirock]

Yeah, I can't see the beam on my measured 170mW 660 from a few degrees away. If it look basically down the host and the beam, I can barely see it. This is without smoke, and just in a very dark room inside. I haven't tried it outside or with smoke/fog.

 

[blrock]

I recently stripped a short open can red laser out of a SWF**** bluray sled. Can't remember the exact name.
Ran it at 380mA and I found the beam to be very visible. Even outside looking perpendicular to the laser is was visible

Oh, and I only paid $24 for the sled on ebay. This gave me +-300mw red and +-300mw violet laser...BARGIN

 

[AUTO XX]

The combines are roaring around right now, there is so much dust in the air that all of my lasers look like they are over 2 watts
The 1.6W 445 even burns little pieces of chaff as they pass through the beam sometimes.

 

[midias]

My 660nm at ~200mw

 

[extremeodd]

I just got an o-like 200mw waterproof and in the rain I can see the beam as well as my 30mw green. It just feels.... weird to be able to make a green and red dot on a building far away and have em both very visible. So used to very weak reds that its sick.