How much difference should I see between my 30mW 532nm, vs a 200mW 532nm?

***Noob question alert***

What I'm getting at here, is that I'm now considering buying an O-Like 200mW green(532nm) laser. Probably the "Power Rock", and maybe it's the "Cute" one, I'm not sure...(Whats with these names?) But it says Power rock.

I've had my 20-30mW 532nm laser for 5 days now, and outside without any fog to speak of, I can usually see most of the beam when I point it towards the woods 200' down the street. The beam is visible even though there is a street light just 45 feet from where I'm standing, and another light about 100 feet away. The beam is not super bright, but I can usually see it.

1. So, if I were to buy the Power Rock 200mW laser 532nm, how much difference would I see vs this 20-30mW laser? I ask because sometimes things like this arent so obvious. If you want to double the volume of a stereo, supposedly you must up the wattage ten fold! But the Power Rock should be about 6-10 times more powerful than what I have now if the PR is any good and is accurately measured.

2. Also, I know that some light color frequencies are better for heating up and burning certain objects, but which color frequency is best, watt for watt? If you had 150mW lasers in every popular color frequency, and they all had similar divergence and were made by the same co., which would typically burn or heat up things better? Does that also mean that color(whichever it may be) is the most damaging to human eyes?

3..Lastly, if it were you, would you buy the 200mW Power Rock now($139), or wait a bit and buy the 400mW O-like laser for $214? Would I notice a much bigger difference in 400mW vs 200mW? The 400mW one is not a Power Rock, and has a different host.

I just dont want to waste money if it is going to be like stereo equipment, which means I have to increase power ten-fold to notice much difference.....

I believe relative brightness is a x^2:x ratio. 4 times the power equals 2 times the brightness, 16 times the power equals 4 times the brightness. What do you plan on doing with the 400? it might be painful to look at that indoors the lower the wavelength the more energy is absorbed, IIRC. so a 405 would be better at burning than a 532.

I would buy the 400mW green just because it will burn much better and nobody can build a 400mW but we can build a 200mW very easily

RyanElectro said:

I would buy the 400mW green just because it will burn much better and nobody can build a 400mW but we can build a 200mW very easily

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Really? Its not currently possible to build a 400mW 532nm laser? So maybe it's worth the extra $75. Besides if you do the math, the 200mW 532($139) from Olike costs almost $70 per 100mW, but those extra 200mW you get with the 400mW laser from Olike($214) only cost $37.50 per 100mW. Dont know if thats a good way to look at it, but it sounds good!

Just something to note: John Capelo is almost right about relative brightness, except not quite. It's a square law. So four times more power is twice as bright, but 16 times as much power is not 8 times as bright, but four times as bright. Square root of the percentage difference will give you the brightness difference.

Thanks :beer: edited to reflect the correct info now!

If all you are looking for is to be able to clearly see a beam at night outside a power rock 50mW is OK and the 100mW very OK and both are Relatively. with a capital R. safe compared to 200mW and 400mW.

With any of them you really need some good protective goggles that filter out both green and infrared---none of the o-like lasers has an infrared filter and what you can't see in this case could harm you.

Be very very careful---you only have one set of eyes---a 400mw green can burn your retina in less time than your blink reflex which is 1/4 second if you sustain a direct hit in the eye and even if not a direct hit --an indirect hit reflected for split second off of something you were not aware would/could reflect can cause damage ----also damage is cumulative over time. According to ANSI standard Z136.1 the power density necessary to cause irreversible eye damage of 26mW/cm squared based upon 1/4 second exposure.

Survival Lasers has a couple of good pair that filter both. The 2 at the top of this page will do the job -- see:

Laser Safety

LightBeamConcentrate said:

Really? Its not currently possible to build a 400mW 532nm laser? So maybe it's worth the extra $75. Besides if you do the math, the 200mW 532($139) from Olike costs almost $70 per 100mW, but those extra 200mW you get with the 400mW laser from Olike($214) only cost $37.50 per 100mW. Dont know if thats a good way to look at it, but it sounds good!

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Yes, it's virutally impossible to build a 400mW 532nm laser. Do you see any self-built 400mW hobbyist laser here? Yup, there aren't. Besides the point, no one really likes building greens anyway.

Get the 400mW and get some good safety glasses with them.

Approximately 4x power is required to appear 2x (twice) as bright. Nonlinear response of the eye and all that.

200mW will not appear much more then twice as bright as 30mW.