Can you see a 5mw red laser beam in the dark or in light

[Ty32]

i want to know if you can see the beam of a red 5mw laser at night or in the light

 

[ZRaffleticket]

Unless you use fog/smoke or have a very dusty house, no you won't see a beam.

 

[Shakenawake]

If you have pitch black conditions, thick thick fog, and your eyes have adjusted to the dark for like 10 minutes, then maybe.

In short, no.

300mW of 660nm is barely more visible than 5mW of 532nm

 

[LtKernelPanic]

In a lit room no. In a pitch black room you should without too much trouble. I just checked with a 7mw 635nm which is more visible than the standard 650nm common red but I had no problem seeing the beam as long as I was looking roughly parallel to it.

 

[EpicHam]

Not really .
First of all , we need to refer to the Human Eye Response graph.

Taking a 15mW 552nm as a benchmark .
Its apparent that you are talking about almost 1/17 of its sensitivity.

 

[Leodahsan]

If you have pitch black conditions, thick thick fog, and your eyes have adjusted to the dark for like 10 minutes, then maybe.

In short, no.

300mW of 660nm is barely more visible than 5mW of 532nm

Barely? What do you mean by "barely"?

@Epicham
Acording to CIE color table and including rayleigh scattering, a 15mW 552nm laser should have a 101X stronger beam than a 5mW 660nm

Use this tool: Beam: (491nm 1mw) vs. (666nm 1mw)

 

[EpicHam]

Barely? What do you mean by "barely"?

@Epicham
Acording to CIE color table and including rayleigh scattering, a 15mW 552nm laser should have a 101X stronger beam than a 5mW 660nm

Use this tool: Beam: (491nm 1mw) vs. (666nm 1mw)

you're right.

 

[hwang21]

In any case, in general, you will NOT be able to see the beam of a 5mW ~650nm laser at night, unless it is pitch dark and your eyes are fully adjusted to the darkness.

 

[EpicHam]

In any case, in general, you will NOT be able to see the beam of a 5mW ~650nm laser at night, unless it is pitch dark and your eyes are fully adjusted to the darkness.

In case you're wondering what does pitch dark night looks like when your eyes are in scotopic vision .

It looks like this.

 

[hwang21]

I'm saying pitch dark as in totally dark room, you can't see your hand in front of your face kinda thing

 

[EpicHam]

I'm saying pitch dark as in totally dark room, you can't see your hand in front of your face kinda thing

well.. it doesn't have to be pitch dark.
It'll help if its VERY DUSTY and smoggy with LOADS of particulates

 

[hwang21]

Well in that case it wouldn't be a "typical" situation

 

[EpicHam]

Well in that case it wouldn't be a "typical" situation

a 5mW red will work in such situations

 

[Ty32]

if i use a military smoke firework will i it

 

[ToneLoke]

I can (barely) see my 5mw 635nm laser beam at night when looking parallel to it.

 

[Ty32]

if i use smoke can i see it