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ArcticMyst Security by Avery

blu-ray burning

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May 18, 2008
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There were a few posts here about why blu-rays seems to burn better than red...  I was playing w/ both last night.  My blu-ray is ~100mw, and the red is ~300mw.

Blu-ray definitely burned almost as well as the red on most surfaces, and burned better than the red on some!  
I could ignite white match heads w/ the blu-ray w/ ease.  The red wouldn't touch them.

So, my first guess is that things absorb UV more than red.
2nd guess is that it has to do w/ the energy contained in higher frequencies.  There's more energy contained in each photon.

(but them I'm not sure if there is a trade off.  I'm no physicist, but I know a lot about electricity. I keep thinking about ohms law.   You can have low volts, and high current, and it would kill you instantly.  You could have another source of the exact same total power, but this time very high volts, low current, and the power would pass right over you w/out any damage.  I guess it doesn't matter at all, other than to satisfy my curiosity, but is there a similar relationship in the EM spectrum when going from low frequencies to high frequencies?)

Oh, then another question... How the ___ do people light matches and pop balloons at a distance??  i couldn't get anything over about 5 feet, and I know the lasers are powerful enough!  They both have meredith lenses, which people say are a little tougher to burn things w/.... but still.  I couldn't even pop a black balloon about 10-15 feet away from me.
 





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it takes a very sensitive hand to focus out the beam to far distances to pop balloons and whatnot. its just a matter of determination.

You are correct about the material absorption of light. I've noticed my 100mW blu ray can easily light red or white matches that my 300mW red can't, the red needs a dark tip.. its just the wavelength of the light being absorbed or not.
 

UMO

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May 24, 2008
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Hmmm... I have my 405 @ 100mA and cannot light a red match. Even when I focus it up close it still won't do anything but make a small black mark on it. I just have the cheap Aixiz module and I seem to be leaking light out of the sides. Any ideas on how to collimate it better?
 
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I was smokin' tiny ants the other night with my 135 mW BR pen. In fact it just lit a black match instantly. Are you sure you focus to that tiny dot?

Mike
 

UMO

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May 24, 2008
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I'm sure man. It wasn't a strike anywhere match though. It stings my skin and, with sunglasses, I can see it is really focused.
 
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May 18, 2008
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Triple hx, I have NO idea what could cause that.... if it stings your skin, it should certainly ignite the matches. w/ mine, matches will catch fire w/in a second or 2.... it takes at least 5 seconds before I feel a sting on my skin.

get some new matches :D
 
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Triple Helix said:
Hmmm... I have my 405 @ 100mA and cannot light a red match. Even when I focus it up close it still won't do anything but make a small black mark on it. I just have the cheap Aixiz module and I seem to be leaking light out of the sides. Any ideas on how to collimate it better?

hmm, I just turned up the current on my 803t based pointer from 90 to 100 mA, and it made a very noticeable difference in how well it can burn. I do need to focus it, but it will ignite unsharpied wooden safety matches up close. I'm using the Meredith glass lens.

This video shows is igniting one from about a foot:
http://www.youtube.com/watch?v=6qdePtha0kg
 

UMO

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wicked1 said:
Triple hx, I have NO idea what could cause that....  if it stings your skin, it should certainly ignite the matches.  w/ mine, matches will catch fire w/in a second or 2.... it takes at least 5 seconds before I feel a sting on my skin.

get some new matches :D
Yeah I thought it was odd too. I'm a white guy too so I'm not absorbing that much light. I think the strike anywhere matches have phosphorous in so I'll probably try those out when I go shopping next.
 




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