Burning+Visibility Data?

[linkmaster03]

I was wondering if someone could give me some good benchmarks... like mW for burning benchmarks, and visibility benchmarks in day/night for green and red lasers.

Hope someone can help.

 

[Schrecken_Licht]

Do you mean like how many mw are needed to burn? How many to be visible in daylight? If that's what you mean it will all pretty much depend on wavelength. As for burning, higher wavelengths tend to burn better (such as a blu-ray burning better at the same power than a 660nm red), but it also depends on what you are wanting to burn.

Green lasers are the most visible to the human eye, so at any given mw a green will be most visible in daylight (and at night). Of course, daylight - are you talking outdoors in the sun, in the shade or indoors on a sunny day? That's a lot of variables...

Burning is a tough question because there are even more variables - like how well/if the beam can be focused, the substance being burned, and as said before the wavelength. Pretty much any visible or near-IR laser in the 100mw range will burn black materials reasonably well and should light a black-tipped match.

 

[Event_Horizon]

 As for burning, higher wavelengths tend to burn better (such as a blu-ray burning better at the same power than a 660nm red), but it also depends on what you are wanting to burn..

I believe you meant to say lower wavelengths. Otherwise, I can't really add anything, that pretty much sums it up. I would recommend a 100mW green laser for all your burning and beam visibility purposes. Any more and it gets prohibitively expensive.

 

[linkmaster03]

Thanks! Would a 200mW red be visible at night time?

 

[Event_Horizon]

Thanks! Would a 200mW red be visible at night time?

Only just barely. You'd have to be looking straight down the beam to really see anything. A 200mW green would burn better and be something like 20x more visible. You will not be disappointed with green. I promise.

 

[Abray]

I have to disagree about the red being visible, though...

My red is about 250mW, and it is about the same brightness as my 5mW green laser, if not brighter. It may be the extreme humidity (many times averaging about 80%) where I live, but I can see the red beam pretty well.

However, the 100mW green would dwarf the red in comparison.

 

[Event_Horizon]

That possible. My reds are about 100mW and the beam is very very dim at night and invisible with dim indoor lighting. Could be just me though.

 

[Schrecken_Licht]

[quote author=Schrecken_Licht link=1215657671/0#1 date=1215659249] As for burning, higher wavelengths tend to burn better (such as a blu-ray burning better at the same power than a 660nm red), but it also depends on what you are wanting to burn..

I believe you meant to say lower wavelengths. Otherwise, I can't really add anything, that pretty much sums it up. I would recommend a 100mW green laser for all your burning and beam visibility purposes. Any more and it gets prohibitively expensive.[/quote]


Yeah I did.....that's what happens when you try to answer a post in a hurry! :-[

 

[Event_Horizon]

Just take your time. It's not a race! ;D I always read over my post at least once before I post it. If it's long I read it again after I post it, just in case.

 

[linkmaster03]

Thanks guys, I'm going to definitely go for a greenie. When my 5mW impresses me and my relatives, a green burner... :-?

 

[RA_pierce]

Visibility depends a lot on individual eye sensitivity too. I can see the beam of a 5mW red pointer at night, only just, but I can see it. And when I'm looking directly down the beam (coming at me) It is reasonably noticable. It may seem weird or unsafe, but I can even burn objects up close with my X105 (100+mW green) with no goggles and I have no adverse effects on my vision. So sensetivity to light varies alot.

Green is the brightest (555nm is the peak of sensitivity) and as the wavelength increases or decreases the sensitivity decreases. I would imagine 5mW of 650nm (red) would be about as bright as 5mW of 473nm (blue) and 593.5nm(yellow/orange/amber) would be close to that of 532nm. Bluray (405nm, violet) would be less visible than 650nm but more visible than 780nm (NIR or deep red).

Burning for green, +50mW will burn a little, pop balloons, and simple stuff... +75mW will be just about the same but be able to light matches when focused, 100-130mW will burn pretty much everything and it'll be bright as hell. Any more power than that and it burns everything, just faster. This is with a beam diameter of ~1.5mm. More than 600mW will set paper on fire, and once you start counting in watts, you can cook pretty much whatever you want.

Burning for red is basically the same, but normally red lasers have a larger beam diameter so burning would seem to be less efficient. Also, red is a longer wavelength than green, blue, etc. so the energy density will be slightly less, however the difference won't be very noticeable.

Blu-ray burns the best out of visible lasers because of it's shorter wavelength, so a violet laser could probably light a match with 30-40mW when focused.

Edit: I don't have personal experience with all these wavelengths so feel free to correct me if I am wrong about any of it