looking towards source = more noticeable beam?

[ixfd64]

A few days ago, I was trying to measure the divergence of a generic laser pointer (it was really bad, like 6 mrad or something) when I noticed a very faint beam. This only happens when I look in the direction of the source of the laser. Under normal circumstances, I could never get a visible beam from a <5 mW red laser pointer except maybe in a steamy bathroom. Is there an explanation for this?

The beam was much dimmer than that of my Core, but it was just beautiful. I tried to get some beam shots, but the beam didn't show in the pictures as my camera doesn't handle low-light settings very well.

 

[Raiden Gekkou]

Maybe you're picking up faint IR? I used to stare into the red laser pointers that you get from the dollar store sometimes, and would notice a bit of a beam when shining it to the side of my eye. I could also see little "shapes" moving through the beam while doing this.

 

[Jacob32123]

http://laserpointerforums.com/f44/beam-brighter-reflected-off-mirror-54035.html

 

[Dr_Evil]

Maybe you're picking up faint IR? I used to stare into the red laser pointers that you get from the dollar store sometimes, and would notice a bit of a beam when shining it to the side of my eye. I could also see little "shapes" moving through the beam while doing this.

Unless it is DPSS red, there won't be any IR. Not only that, he said he saw a faint beam.

A few days ago, I was trying to measure the divergence of a generic laser pointer (it was really bad, like 6 mrad or something) when I noticed a very faint beam. This only happens when I look in the direction of the source of the laser. Under normal circumstances, I could never get a visible beam from a <5 mW red laser pointer except maybe in a steamy bathroom. Is there an explanation for this?

The beam was much dimmer than that of my Core, but it was just beautiful. I tried to get some beam shots, but the beam didn't show in the pictures as my camera doesn't handle low-light settings very well.

That will happen with almost any pointer. The beam will be brighter if you looks torwards the source. You won't notice a beam with most low power pointers unless you look torwards them. You'd need a really low power green to not really see a beam during the night until to looks towards it.

 

[Cyparagon]

This is a well known phenomenon called Mie scattering.

 

[Sigurthr]

Cyparagon beat me to it. Sir Rayleigh ftw.