Why do you need this laser??

[Eudaimonium]

How is #5 different from #4?:thinking:

It's not.
Except that he described pointing the 150mW greenie into airplanes...

You are aware that you would endanger the lives of 200+ passangers to save yours?

 

[Gsquared18]

:wtf:I didn't say I'd shine it in the cockpit or at the passengers, I said "Across the bow (nose) so they'd report it.

 

[daguin]

:wtf:I didn't say I'd shine it in the cockpit or at the passengers, I said "Across the bow (nose) so they'd report it.

You do not appear to understand the concept of divergence.

Peace,
dave

 

[Gsquared18]

Listen I get the whole laser in the cockpit thing and I don't think anybody in this entire community would do such a thing but that's not how or why I said what I said. The "Shot across the bow" was tongue and cheek humor.

Obviously if the plane is landing, then I would know I was close enough to a city or town and wouldn't need the signal. Unless, I was stuck with let's say a broken leg and if that were the case, I'd put the beam way out in front and just pray they can see it.

If I'm miles from any human and I see a plane way up in the sky, I'm going to do whatever it takes to get them to notice me without the intention of bringing down the plane.

Odds are If the plane is in normal flight and 30,000 feet in the air, there is no way, I'd even be able to hit any part of the surface of the plane or shine the beam in front of them so I'd be S.O.L.

Look, I'm just saying that it's somthing I carry with me when I go out into the mountains and would use it in some way if I were lost. There is no "exact plan" on how to signal a flying object safely with a laser pointer but you gotta believe that any responsible adult would use their best judgment if they were actually in a situation like that.

 

[Gsquared18]

You do not appear to understand the concept of divergence.

Peace,
dave

Thanks for the slap across the back of the head. Now can you explain what you mean because you're right, I have no clue.

 

[daguin]

Thanks for the slap across the back of the head. Now can you explain what you mean because you're right, I have no clue.

No. I think that you should look it up.

Do not get me wrong. I completely disagree with this whole "laser in the cockpit" problem except in the last stages of approach. Even then, "temporarily blinded" at most means that the windshield was "dazzled" or the pilot's night vision was diminished for a short time. "Pull up and go around" is done all the time.

Look up divergence. Find out or estimate what the divergence of your "pointer" is. Calculate how wide your "beam" is at 30,000 feet.

Now, how are you going to "aim across the bow" or even know where the "edge" of your beam is.

Even in the unlikely event that the pilots noticed it, the report would read something like, "Someone in the Cleavland National Forest area shined a laser at us."

Peace,
dave

 

[Gsquared18]

You make a valid point that just because they see it doesn't mean alarms are going off in their head to call it in as an emergency. There's some irony for ya, use it to save your life and you'll never get caught (or found in this case). Hit a plane by accident while star gazing and wind up doin time. Guess I'll just use the laser to set the forest on fire. That'll get their attention.:evil:

 

[daguin]

You make a valid point that just because they see it doesn't mean alarms are going off in their head to call it in as an emergency. There's some irony for ya, use it to save your life and you'll never get caught (or found in this case). Hit a plane by accident while star gazing and wind up doin time. Guess I'll just use the laser to set the forest on fire. That'll get their attention.:evil:

Yeah. The ones getting into trouble now are mostly just naive. If it was a coordinated attack, the perp's would know better than to do it from their house and would split right after the attack.

This is totally off topic, but that is how a MAJOR fire was started in San Diego County a couple of years ago. Of course it was matches not a laser Some guy got lost (drunk IIRC) and started a "signal fire" that got out of hand. Literally billions of dollars in property, labor, and lives lost because some idiot went into "wilderness" unprepared. Sorry -- Pet Peeve

Peace,
dave

 

[Gsquared18]

This is totally off topic, but that is how a MAJOR fire was started in San Diego County a couple of years ago. Of course it was matches not a laser Some guy got lost (drunk IIRC) and started a "signal fire" that got out of hand. Literally billions of dollars in property, labor, and lives lost because some idiot went into "wilderness" unprepared. Sorry -- Pet Peeve

Peace,
dave

With that piece of good news, I have exhausted all my options for survival. I'm just going to lay down and let the bears have at me.:beer:

 

[daguin]

With that piece of good news, I have exhausted all my options for survival. I'm just going to lay down and let the bears have at me.:beer:

That's what I always do. Of course after I've been in the field for a few days not even a bear is interested in me :yabbem:

Peace,
dave

 

[Noctis]

Honestly speaking, nobody really has a "need" for a laser(aside from the addiction of course).

I suppose it can come in handy to check that everything is level when you're doing construction or putting a shelf on your wall, but you don't really need a >100mW laser for THAT now do you? Unless your house is the size of a football field.

Getting stranded away from civilization seems like an unlikely scenario no matter how you look at it, and I'm sure a cell phone or radio would work better.

Self-defense is a moot point, as a laser dot is SMALL and you have to point it in their eyes, which might be kind of hard to do if the guy is already in your face or is charging at you rapidly. Against someone with a gun, I've always suspected that it might make them shoot blindly at you, which could hurt either you or someone else. Besides which, even if his left eye is blinded, I'm sure his right eye is still up to the job of tracking you down.

I'm also pretty sure that almost everyone in this community(the laser forum, not the whole neighborhood) has a laser with >5mW output in mind when fantasizing about self-defence. I'm fairly confident that the kind of power output we're talking about can cause permanent eye damage, which will lead to those pesky legal charges. It's a bit ironic seeing as how those charges will come from the criminal, but it WILL happen.

I'm also pretty sure that my $115 Emerson switchblade is a LOT more practical than a $200 laser pointer if self-defense becomes an issue.


With all that said....yes, we're paying hundreds of dollars for pocket-sized entertainment. Though worse things have been done(especially people with expensive zippo lighters and Rolex watches). I still say it's better than spending almost $10 for a pack of cigarettes. A couple months without smoking and you'll have enough spare change to buy a powerful laser.

 

[Gsquared18]

Honestly speaking, nobody really has a "need" for a laser(aside from the addiction of course).


Getting stranded away from civilization seems like an unlikely scenario no matter how you look at it, and I'm sure a cell phone or radio would work better.

I usually skim each thread and don't read every word but I don't remember seeing anybody say they needed a laser but you're right, besides people in construction and maybe certain areas of science, the rest of us don't need them.

As far as the very rare chance of ever getting lost or stuck out in the middle of nowhere, the nowhere's I go don't have ANY cell coverage or radio reception. I didn't go out and spend $200 on my 150mW Opto to use as an emergency beacon device, I bought it to be the coolest middle-aged dork on the block but as I said before, I carry it with me when I go into the mountains just in case I need it it for something. If it doesn't work, so be it.

I originally put it in my camera bag because I do a lot of night time long exposure time lapses with my DSLR camera and the laser provides me with a great way of getting focus on a far away object in pitch black conditions. I just laze the object or area I wan't to shoot and that'll allow me to get accurate focus thru the camera. Later I realized it may be something I can use if I ever got injured or lost in the mountains.

 

[StardustSprinkles]

^you have a point there... But good luck getting anyone's attention with a DPSS green if it's nippy out... My 150 pen pushes out faint pink light when it's below freezing out.

 

[Eudaimonium]

^you have a point there... But good luck getting anyone's attention with a DPSS green if it's nippy out... My 150 pen pushes out faint pink light when it's below freezing out.

It will start glaring and raining hell, as soon as it warms up (within a minute or two usually).

Nd:YVO and KTP crystals are shrinking and expanding with temperature changes, microscopic movements are enough to misalign it and stop from lasing.. but when it warms up... party time

KTP crystal's work temperature is 80°C IIRC, pretty high huh?

 

[Gsquared18]

Nd:YVO and KTP crystals are shrinking and expanding with temperature changes, microscopic movements are enough to misalign it and stop from lasing.. but when it warms up... party time

I don't know what all that means but man you just sounded so cool:drool:

 

[Eudaimonium]

I don't know what all that means but man you just sounded so cool:drool:

Hah thanks, but let me make myself clearer.

You see, every material has it's temperature expansion properties.
When a material is heated, it will expand in volume of space it takes.

When it is cooled, it will shrink.
Best example is when you dip the ballon in liquid nitrogen. You have vides of that on YT a lot. The air inside will shrink and ballon will look like a bit oversized dry plum

There is experiment you can do, you can grab a meter long copper rod, and heat it with blowtorch eaqully. You can notice it will became longer for a milimeter or two.

Every material does that.

Now, you have your KTP crystal inside your green laser which is alligned with microscopical precision.
When you take your laser outside, the crystal will cool down, and couple of micrometers it shinks is enough to move it out of alligment, and it will not lase.

Get it?