Does color affect light intensity?

Hey guys! As you may be able to see, I'm new to this forum and lasers in general. I was thinking of buying a violet laser pointer from dragon lasers(Violet Laser Pointers : Dragon Lasers), and I had some questions.

- Does the color of a laser affect how strong it is?
For example, would a green laser of 50 mw be more powerful of a violet laser of 50 mw (I'm pretty sure it doesn't but I'm just trying to be sure)
-Which goggles would protect against violet light? Would the ones that protect against blue light be just fine? I'm planning on buying one of these (Laser Safety Glasses, Goggles, Eyewear :: Dragon Lasers)
-Is there anything else required to use the laser properly other than the laser itself and goggles

Thanks so much guys!:san:

Yes, the brightness of a 405 will be far less than a 532 or 520 of equal power. Power transmitted will be the same. The 405 will be absorbed better and therefore would burn better. Nothing besides the goggles is needed, just make sure you're using a safe brand of batteries such as Efest.

P.S. The beam on a 405 laser is barely visible even at night unless it's 800mw and even then it's not bright.

Crazlaser said:

Yes, the brightness of a 405 will be far less than a 532 or 520 of equal power. Power transmitted will be the same. The 405 will be absorbed better and therefore would burn better. Nothing besides the goggles is needed, just make sure you're using a safe brand of batteries such as Efest.

P.S. The beam on a 405 laser is barely visible even at night unless it's 800mw and even then it's not bright.

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OK, so then I should probably get a green or blue laser if I want to burn things and such?

An 800mw violet will burn very well. Blue will burn nearly as well and is available in higher powers. Green is expensive and available in powers similar to violet for a much higher price. Get a blue if you want only to burn. The beam is usually visible on the higher power blues of more than 500mw. Please use goggles when looking at the dot.

Yes, research into luminous efficacy.

Crazlaser said:

The 405 will be absorbed better and therefore would burn better.

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While that's correct, there are other factors.

Smaller spot when focused and better beam quality from the 405nm diodes we have access to lends itself to burning too. 405nm can be focused to a smaller spot than anything of a longer wavelength. The round beam and improved divergence helps.

@OP - Proper laser safety goggles are a must as everyone has already pointed out. They'll protect your eyes and make focusing the dot much easier.

405nm is very dim compared even to 445nm. 445/450/460 etc are available in higher powers, so they may be brighter than available 520/532nm lasers. I DO NOT recommend starting with that sort of power if you're new to lasers. Very dangerous.

520nm or 532nm are the brightest as your eyes are most sensitive around that wavelength (green), but as others have said, green is the more expensive option if you want lots of power.

Depends upon how you think about it, shorter wavelengths are more energetic but our eyes are also less able to perceive them, when higher/shorter than about 555nm/green.


RHD's Relative Perceived Brightness Calculator. Compare brightness @nm: Relative Laser Beam Brightness Calculator: (560nm 1mw) vs. (669nm 1mw)

It is interesting that a lot of people regard 555nm as the brightest wavelength, but this is only true for photopic vision. Photopic vision occurs when your eyes adjust to the sun at its brightest luminosity. Technically the brightest wavelength you can own is 507nm when Scotopic vision takes over. Scotopic vision is when your eyes adjust to low light conditions (night vision). When you want to view your lasers brightness do you go outside in blinding sunlight or go into a dark room? This is the comparison:

555: Photopic : 683.0 lm/W
555: Scotopic : 683.4 lm/W
507: Photopic : 303.5 lm/W
507: Scotopic : 1700.0 lm/W

The wavelength that actually is brighter on average than any other is ~522.6nm (523nm). If you take into account Mesopic data which is more like average lighting situations that we normally use our lasers in then 523nm comes out on top. Where 555 is brighter during daytime but decreases towards nighttime conditions and vice versa for 507. But 523 maintains high luminosity in all light levels. Below is the mesopic data for 555,523 and 507.

Mesopic:
555: 925.5 lm/W
523: 1099.8 lm/W
507: 953.5 lm/W

Now I want a 507nm laser, and RHD's percieved brightness calc needs another settings option.

To be fair, scotopic vision kicks in when light intensity drops to below 0.001lx. So it isn't very often you actually use scotopic vision. Your typical specialised dark room would be 1-2lx. This is within the mesopic range of 0.001lx to 3lx. For that you want 523nm. This is why 532nm DPSS (only being 9nm away) stays bright in what ever situation because it is close enough to the average peak.

If i want a laser that can REACH as far as possible.
Say 10,000 or maybe even 50,000 meters into the sky.

Should I then aim for "longer" nm? over "shorter" ?

For example.
If i buy a laser on 3-5 W with a normal 445.
Will that reach shorter distance than if I get a 2W 530 nm laser?

How can i calculate which one reaches furthest?

You just posted a new thread about this here.

Crazlaser said:

You just posted a new thread about this here.

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I sure did! Realized it's maybe better to do a thread about it since they are related but not the same question.

Alaskan said:

Now I want a 507nm laser, and RHD's percieved brightness calc needs another settings option.

Click to expand...

In any lighting conditions light at or close to 555nm will always appear brighter.

Creativelavashark said:

OK, so then I should probably get a green or blue laser if I want to burn things and such?

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Burning stuff with a laser is about as exciting as using a magnifying lens and the sun as your light source. It will lose its allure.
This is the way to burn stuff.
http://laserpointerforums.com/f57/burning-i-am-not-impressed-98886.html

If you're tired of burning stuff, you need a bigger laser. :eg: