GREEN LASER DIODE $25

[bamacre]

Originally posted by: Knavish

Originally posted by: bamacre
How would this work for spiders found crawling on walls?

If the wall is wood or drywall it will catch on fire before the spider does.

:laugh: Thought so.

 

[brownzilla786]

Ive always wanted one, all I care about is if I can see the beam at night...thats just kick ass! I would just go on walks carrying that thing around and shoot at the starts

 

[imported_MGM]

I would love to have one too. Can anyone suggest any good ones that aren't too expensive? Like brownzilla said, I just want a beam that's strong enough to cast a good, solid beam at night (or heck, if it works in the day too that'd be awesome). Any suggestions would be great, but I don't want to spend TOO much

MGM out

 

[tomatom]

The FEAR of the invisible IR radition is warrented , but , any
IR leakage is SCATTERED and not in a focused beam . If you
have a Sony low-light Video Camera or a night vision scope ,
then you can " see " the IR light emitted .

O f course , no one wants to damage someone's vision , so
be extremely cautious while doing your " light shows " on buildings
and trees and signs at night .

Don't duct tape one to your paintball spitter and take out surveilance
cammeras . That would be very ILLEGAL !

 

[tealk]

Ok aren't these things like $5.99 at Kmart?

 

[nakedfrog]

Originally posted by: tealk
Ok aren't these things like $5.99 at Kmart?

Probably not green ones.

 

[dud]

A few things to consider:

First, I looked over the entire ad and from what I could see from the eye-safety sticker on the laser these are not Class 3b eye-safe lasers. If used improperly you (or someone you love) will damage the cones in the back of your eyes.

Secondly, what is your sight worth?

Third, refer back to the above ...

 

[bamacre]

Originally posted by: dud
A few things to consider:

First, I looked over the entire ad and from what I could see from the eye-safety sticker on the laser these are not Class 3b eye-safe lasers. If used improperly you (or someone you love) will damage the cones in the back of your eyes.

Secondly, what is your sight worth?

Third, refer back to the above ...

What do you mean by "improperly?"

Obviously, I don't plan on pointing this thing toward anyone.

But should viewers were glasses of some sort when even viewing the beam pointed toward the sky or a tree or whatnot?

 

[dud]

What do you mean by "improperly?"

Of course you would not aim this device at another person ... right? What about if you pointed it at a reflective surface that kept the beam (mainly) intact ... and into someones field-of-view?

My point in posting here is that there are MANY class 3b eye-safe laser pointers on the market today. these devices have a ZERO risk of harming someone's eyes. The devices being pushed in this thread are far from eye-safe and could potential damage your eyesight, or worse, someone else's. Could you imagine how you would feel if you bought one of these and inadvertantly damaged someone's eyesight ... perhaps a childs?

There is no rational reason to own a laser this powerful ... unless of course you are trying to impress someone ... or yourself.

 

[bamacre]

Originally posted by: dud
What do you mean by "improperly?"

Of course you would not aim this device at another person ... right? What about if you pointed it at a reflective surface that kept the beam (mainly) intact ... and into someones field-of-view?

My point in posting here is that there are MANY class 3b eye-safe laser pointers on the market today. these devices have a ZERO risk of harming someone's eyes. The devices being pushed in this thread are far from eye-safe and could potential damage your eyesight, or worse, someone else's. Could you imagine how you would feel if you bought one of these and inadvertantly damaged someone's eyesight ... perhaps a childs?

There is no rational reason to own a laser this powerful ... unless of course you are trying to impress someone ... or yourself.

While I appreciate your response, it didn't exactly answer my question.

 

[pontifex]

you guys have to be careful about pointing these things into the skies as well because of passing aircraft.

 

[tomatom]

There is no rational reason to own a laser this powerful

... until you aim it at a STAR and see the beam appear to touch it...
< a truley jaw-dropping experience >

RECAP : 1. Beam is too bright to look at ! < flinch response >
2. IR leakage is not colimated , but scattered like TV remote .
3. Momentary button switch . Usage is usually 3sec on , then off .

< Ramble > My 3-watt LED flashlight is TOO bright to look at . If you were
hiking,biking,sailing , this would be the best night signal for any aircraft SEARCH .
Web Page tells how to take the Hi-Power IR laser out of your CD-DVD
writer and mod it into a flashlight for burning holes in paper targets . MUST
wear IR goggles for this . If the GREENIES were very dangerous , there
would be thousands of blind cats by now .
! BE ADULT . BE CAUTIOUS , BE SAFE , BE CONSIDERATE !

 

[tealk]

Originally posted by: nakedfrog

Originally posted by: tealk
Ok aren't these things like $5.99 at Kmart?

Probably not green ones.

OK Sorry, so.....$6.99?

 

[Stewb]

Originally posted by: tealk
Ok aren't these things like $5.99 at Kmart?

There are so many things wrong with this post...

---

Like your presence on our forums. Good bye.

Harvey
AnandTech Senior Moderator

 

[Jim]

.

 

[El Norm]

I'm such a sucker for stuff like this. I ended up ordering the 150mW and a 30mW (after i heard u can "overclock" these) so if i can get the 30mW one up to par with the 150mW i will try returning the 150mW.

But i've been interested in stuff like this since i was a kid... lol i can wait till this thing arrives in the mail... =D

 

[Shack2]

What exactly is the difference between the True and non-true versions besides the price?

 

[VinceDee]

"True" means that reviewers have verified that the laser comes very close to the claimed manufacturer output. If it doesn't say true then it means that 1)they haven't tested it yet or 2)it doesn't come close to the specs.

 

[Auryg]

Originally posted by: El Norm
I'm such a sucker for stuff like this. I ended up ordering the 150mW and a 30mW (after i heard u can "overclock" these) so if i can get the 30mW one up to par with the 150mW i will try returning the 150mW.

But i've been interested in stuff like this since i was a kid... lol i can wait till this thing arrives in the mail... =D

Be really, really careful with a 150mW one. Seriously. Get some IR goggles at the very least. I split second of the 30mW is enough to cause a spot in your vision that may or may not heal - lord knows what the 150 one would do.

Is there anything you could put over the tip of these to block the IR? Like a flexible filter you could just tape around the tip?

 

[Modelworks]

We used exposed film as an ir filter for projects.
Not sure how it works with lasers.

I forgot the above passes IR, and blocks visual.
You would need the opposite, block ir, pass visual.
So that wouldn't work.


Found these:
http://www.optics-online.com/IRC.asp?PN=IRC20-10R
12.50 a set

I've got a laser power meter , so I might order one of these and see how good these filters are.
My meter only goes up to 20mw so I can't measure the higher rated ones.

I built lasers as a hobby years ago using mirrored tubes, high voltage and various gases but the whole diode trend and ease of use made the former seem cumbersome.

Nothing like making your own holograms

 

[jsxlynn]

Originally posted by: Mongals
"With the use of laser pointers that are more powerful than five milliwatts, there would likely be damage to the actual vision," he says. "Functional damage could occur within seconds."
And the damage is permanent.

"This is a potential hazard to people?s eyes, but rarely is it going to be a practical hazard because the aversion reflex we have naturally will cause a person to blink or turn away from a laser light."

This is quite untrue. Depending on many factors including divergence of the beam, distance, and actual laser output damage can be done far quickly in as short a period of time of 50 microseconds. The fastest blink reflex that I'm aware of is >50 milliseconds.

I've not much experience in IR lasers but lasers in the UV range can damage far faster than the eye can blink. The person whose vision is now permanently damage is often unaware because the eye is so adept at removing such defects (this is why you don't see your nose--actually you do, but your brain does not bother to pay much attention to it. Look up the Amsler Grid test to see one (and test if you have any UV laser damage--but unless you work where UV lasers are used--it's not likely. I'm not sure about the damage caused by IR lasers as that damages the cornea, not the retina.

The short of it is that if the laser carries a warning label it must be treated as dangerous. Further, if someone were to flash a green laser at the screen of a cinema theater, I personally will call 911 and if the confiscated laser carries a warning label I will file assault charges. At a minimum the person owning said laser will end up paying for an opthomological exam, possibly for ever person in the theater.

Beyond 5mw output these are tools--to be used responsily, not toys.

And for the person who stated that the mw output is usually over-rated--this is not so, in fact if you do some research there are plenty of cheap lasers that emit higher than rated output.

 

[pete777]

Originally posted by: bamacre

Originally posted by: Knavish

Originally posted by: bamacre
How would this work for spiders found crawling on walls?

If the wall is wood or drywall it will catch on fire before the spider does.

:laugh: Thought so.

too bad, was a great idea

 

[BigLar]

Not too ironic that the banner ad on the bottom of this post is for Lasik surgery...(at least on that cycle)

 

[nealh]

Guys I am an Ophthalmologist and fellowship trained Vitreoretinal specialist

We use Argon green lasers for retianl disease treatment....diode laser are used as well

These things are not toys and should never be pointed at anyone or a place where your not intending.....

You will do serious and permanent damage to someone's eyes..if your really unlucky you will hit their macula and potentially make themy legally blind

Not a very nice outcome....skip these stupid things...

Damn... people are stupid so often and these should not be for purchase...lthis IMHO is like a gun that has no consequences becasue the person playing with it doesnt see blood and gore from their stupidty

 

[BigLar]

Originally posted by: Knavish

Originally posted by: bamacre
How would this work for spiders found crawling on walls?

If the wall is wood or drywall it will catch on fire before the spider does.

POPPYCOCK!!!

Let's say you're using a 100 mW laser to light it up for 10 seconds over a 10 sq mm area (0.1 sq cm) that is 1 cm thick.

Let's also assume the density of the drywall is 1/2 that of water (1/2 g /cu cm) and its heat capacity is 1/10 that of water that is, 0.1 cal/g/deg C (so it heats up quicker).

Energy delivered (assuming 100% absorption) = 100 mW * 10 sec = 1 W-sec = 0.25 cal

Volume of drywall heated = 0.1 sq cm * 1 cm (thick) = 0.1 cu cm
Mass of drywall heated = 0.1 cu cm * 1/2 g/cu cm = 0.5 g

So you've delivered 0.25 cal/0.5 g = 0.5cal/g to the drywall.

Temperature rise = (0.5 cal/g) / (0.1 cal/g/deg C) = 5 deg C

So if your house is at 25 deg C, that spot would raise to 30 deg C assuming absolutely no heat escapes the heated zone (adiabatic!).

Now 30 degC ain't cold, but for you Ray Bradbury fans out there, 451 deg F = 233 deg C, and drywall ain't paper (I think its gypsum with a layer of paper on top), so I don't think anything is going to explode into flames within a few seconds...