Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers



Laser Pointer Store

visibility of beams versus viewing angle/distance

zamane

New member
Joined
Feb 4, 2009
Messages
18
Likes
0
Points
0
I am curious regarding the visibility of a green laser beam with a long-distance focus ie more or less parallel beams. I know that especially for green lasers with power greater than 50mW or so, the beam is very visible in low light conditions, but this is from the holder's point of view. How visible would the beam be from an onlooker who is say 300 meters (1,000 ft) away from the beam and has a 90 degree viewing angle (looks perpendicular to the path of the beam). How visible would that be? Would it still be as strong ? Anybody looked at a green laser beam from a distance before (provided that the beam was not directed at them) ?
 

Joined
Mar 1, 2009
Messages
134
Likes
1
Points
0
Re: visibility of beams versus viewing angle/dista

With 50mW it wouldn't be so visible.. I don't think people will notice it unless they scout for a laser beam.
 

a4rings

New member
Joined
Feb 5, 2008
Messages
85
Likes
1
Points
0
Re: visibility of beams versus viewing angle/dista

I had a novalaser alpha 65mW at this time (until I broke it and got a 105mW) I was pointing it in the sky and a friend came over and said that they could see the beam while driving to my house. and he was a few streets away.
 

Warske

New member
Joined
Mar 10, 2009
Messages
145
Likes
11
Points
0
Re: visibility of beams versus viewing angle/dista

A4RINGS said:
I had a novalaser alpha 65mW at this time (until I broke it and got a 105mW) I was pointing it in the sky and a friend came over and said that they could see the beam while driving to my house.  and he was a few streets away.  
Impressive. Was there fog, smog, or rain? Or was it clear?
 

iskor12

New member
Joined
Jan 23, 2009
Messages
2,154
Likes
55
Points
0
Re: visibility of beams versus viewing angle/dista

I currently on have a 15mW green laser and I have tested out exactly what you are asking. It is visible untill you hit about 75 feet away from the laser beam.
 

RA_pierce

Well-known member
Joined
Sep 16, 2007
Messages
3,399
Likes
378
Points
83
Re: visibility of beams versus viewing angle/dista

I've found that about 100mW of green pointed vertically into the sky on a clear night is:

Very visible up to 40 feet
Fairly visible up to 80 feet
Slightly visible at 120 feet
Unnoticeable beyond 130 feet

On a good night when clouds are low the dot can be seen on the clouds pretty well.
When the "spot" on the clouds is viewed from a distance, you can see that it isn't really a "spot." It looks more like what you would expect to see if you directed your laser's beam through a puff of smoke or steam from a distance.

Beam from ~20 feet


Beam from ~80 feet
 

a4rings

New member
Joined
Feb 5, 2008
Messages
85
Likes
1
Points
0
Re: visibility of beams versus viewing angle/dista

Warske said:
[quote author=A4RINGS link=1239884274/0#2 date=1239889112]I had a novalaser alpha 65mW at this time (until I broke it and got a 105mW) I was pointing it in the sky and a friend came over and said that they could see the beam while driving to my house.  and he was a few streets away.  
Impressive.  Was there fog, smog, or rain?  Or was it clear?[/quote]

It was clear out. Nova lasers are so incredible. wish they would make other colors other than green, want more!
 




Top