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ArcticMyst Security by Avery

CHEAP LASER filter prob?

Joined
Oct 6, 2008
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Hi, ok i am a total newbie at lasers but am realy interested in the subject, i bought a cheap green laser from a silly source that was said to be 240mw, well its 532nm wave length thats clear, but the 240?  :-/ I recon not after reading and looking at the posts here,

 Small print i didn't spot said it had a filter fitted which is for safety and meant it would not burst balloons or light matches.... Methinks thats a tad of a con, the laser probably doesnt have any filter and is mabe too weak to burn anything? Although it is very bright and passes the test of being way more brighter etc than the standard red ones you pick up for pennys, the range is meant to be 5500m to 6500m.
so far it does seem to have quite a long range but i can't guage how far it is realy going, But i do know that if i point it at my hand i have no need to go ouch etc,  mabe thats a stupid trick (at least if i got it way wrong). I reasoned that if it won't burst a balloon it would do little to me!.
 Is there any possibility there is any credance to it's power? If there is a limmiting filter which i can remove to get it to burn, how would i be able to tell which is which and what to be carefull of, i have no wish to go blind and recognise the need for an ir filter  in a stronger laser if its build doesnt limmit that already. I do have some electronics knowledge and will start to build something in the next while once i have read enough here, but it would be good if there is some hope for this one meantime. ::)

Further to all thay i found the laser has phenominal range and was stunned at how good it can do and do what it does! except to the burning it has lived up to its sale bab. So if anyone can answer my questions i would realy appreciate it! :) 

I have also bought a load of stuff from Greg at stone tek and will build a burner soon :eek: ,

Better though i found a site that showed all the intracasys of soldering surface mount components (the teeny ones in mobile phones etc) that you need to fit a lot into a small place - usefull for this for sure! I tried to change this with a link and the post was rejected because i do not have ten posts ! botty!
 well the site is by a guy called dr poeth and If you do a search for soldering smt components it should pop up! or try the name. On it he explains how to build tweezer test probes to check the teeny components and all sorts of basic and practical tips on how to go about soldering tiny components. (really really worth a look!)
 

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Joined
Sep 24, 2008
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saddly I've seen friends fall into the same problem as you.  It's a common misconception that MANY people fall into.

I myself have a limited knowledge of lasers, but after some researh and help from on these forums I was able to know certain things needed for lasers.... and lucky I had gone to school for Electronics and a bunch of computer based stuff to help me out to build better lasers than the ones you bought.

Anyhow... let's start off by a few things.

IR Filter... you can buy here.
http://www.novalasers.com/NOVAstore/pc/viewPrd.asp?idcategory=6&idproduct=68
or
if you have an old webcam that is collecting dust you can break it apart and use the IR filter they have on there.  (Webcams are pretty sensitive to IR light.. that's why you can see a light emitting from a TV remote through your webcam at times)
You can simply just glue it on to the existing lens you have and YEY... reduced IR... woo hoo ^___^  but that means less power output.  Ex. you have a 240mw pointer... it could be 100mw of 532nm(green) output and 140mw of 700nm(IR)... remember.. I said could be, but you'll have to test that out later.. I'll tell you that in a sec.
The reason why I suggest you get this is because IR can severely damage your eyes without the proper protection.  Since IR light passess to the back of your eyeball it starts destroying the input receptors back there without you even feeling it (there are no pain receptors on the back of the eyes).  Your eyes will compensate for the loss by using your second eye to fill in those gaps... so you might only get a few chances before you start to lose your vision completely.  I dont know how much you value your eyes, but I recently broke my left wrist when I was hit by a car and it sucks pretty bad just using one hand to do everything.... just think about what it would be with losing one eye.. :p


second... the output.

Generally those points outputs do not hold out it's power that it is rated at for more than 5 seconds.. more like 1-3 then it's a dramatic loss in power over a few seconds... close to 40%-80%, but that varries between pointer to pointer.
A way to get around this is by using a better driver for your laser pointer.  You can find those here.
Dr.Lava - http://www.laserpointerforums.com/forums/YaBB.pl?num=1209418066
Rkcstr - http://www.laserpointerforums.com/forums/YaBB.pl?num=1206947255
StoneTek - http://stonetek.org/shop/index.php?main_page=index&cPath=71
I'd get something adjustable to control the output properly so you dont end up killing your diode.
These drivers will do the same as the driver installed, but the only difference is that they will not come close the the dramatic loss you will get with your current one.

Safety... pretty important.
So since the next part is the fun part.. you still want to be safe.  Since you'll be focusing a beam of light on an object at greater than 5mw I'd recommend either you dont look directly at the focused beam or get yourself some 532nm protective eyewear.  Also found on http://www.novalasers.com

Now that you have a safe and stable laser pointer.. time to test it.
Distance... well theoretically light will travel infinite unless it hits an object... objects such as a building.. mirrors.. dust particles.. or even just our atmosphere.  It really depends on when you do it.. clear sky.. perfect conditions.. how far your eyes can see.. etc. It also depends on your lens aswell. for every step back the dot will increase in size making the dot less and less visable the further back you go.. I beleive the term for this is divergance. So now that you know that... let's move on.
Power.. well Laser Power Meters are EXPENSIVE..  Cheapest product I found was about $350.  It was by Coherent if you want to dig deep into your pockets.  These forums have a DIY version which you'll have to search for yourself.. I dont have them bookmarked cuz a buddy of mine actually owns a pretty expensive one... saddly.. 8hr drive away..  but hey if you get the Coherent then you can see it's output.
Burning capability... matches/balloons work best... I prefer matches since I get em free every time I go buy smokes, but ballons pop easier.  Just use a black marker and color the tips so it absorbs the light better instead of reflecting it.  (a magnifying glass maybe necessary to focus the beam to a more pinpoint source depending on the defraction [I believe that is the word I am looking for] of your laser pointer).  Spread them out... 1ft, 2ft, 3ft, etc until you can no longer light the matches to determine it's burning power by distance.  PS.  I dont recommend this, but you can remove the IR filter for more power.

Conclusion
So after all this hardwork you have yourself a proper pointer.....but that's a lot of work for a cheap laser pointer.
I'd recommend you just return the laser and buy yourself a Nova laser (http://www.novalasers.com) and you'll get quality and it'll be WAAAAYYYYYY better than your current cheap laser.  Beam is way better.. distance is improved.. and burns things pretty well (without a magnifying glass) and instantly with the magnifying glass.. I did my homework on these forums for the best handheld greenie for price and function and so far nearly everyone says that Nova Lasers is the best by far... they never undersell their products (more power than listed from +5mw to +25mw from other ppl who own them).  A lot of em recommended the X75-X150.  I just ordered an X100 myself and I'll post a full review of the product when I run full tests on it.. and really good pictures to add (hehehe.. helps to have a gf who is a photographer =D)  

If you want to know what ppl have been saying about this laser.. you can read my post where I was looking to buy a good green handheld or just search Nova Lasers X75 X100 X125 X150 etc on these forums.  Below is a link to the post.
http://www.laserpointerforums.com/forums/YaBB.pl?num=1223053310

PS... I'm no pro at lasers so if some other uber laser pro can correct me then please feel free to listen to what he has to say.

Aoi
 




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