75mW & Retroreflective Street Signs

[QuackMasterDan]

I know there are a large amount of projects that can be made with lasers, X/Y scanners, spirographs, light tunnels and the like, but what can I realistically do with a high powered laser pointer? I know you can light a match with 100mW+, pop balloons, cut electrical/duct tape, melt plastics, or other dumb time wasters, what are some justifications for spending $200+ on a high powered laser pointer?

I'm still going to get one for star-gazing with friends, get a matrix diffraction grating attachment & fan-spreader for smoke/fog, and as a possible self-defense tool (most punks would question messing with a guy holding something resembling a light saber), but I'd like to know some of your reasons for owning nice lasers.

 

[Kenom]

I'm actually planning a GB to buy one of those flourescent green/yellow signs and cut them up into 2" squares and sell them as laser targets. The nice thing about them is you can put them really far away and shine your laser on it and see it from really really far away. I've got a picture I took (now you gotta remember I live in montana where we have loong stretches of road with nobody for MILES) of a beam going to a road sign a mile away.

 

[LarryDFW]

Even at 43mW returned, it's going to be scattered. So say the scatter is over a 1m square area. and the area of your pupil is 1cm squared , that would make the power that reaches your retina 43/100 = 0.43mW which is safe.

-Adam

The beam that crossed my eye...
looked just like a...
focused laser beam.

Definitely NOT low power.

LarryDFW

 

[dr-ebert]

This just shows how deceiving appearances can be.

As Leibnitz said: "Let's calculate..."

 

[lasersbee]

Hey Ken... they also sell Reflective Tape for automotive a site safety use...

I wonder if you really need to cut up a sign...

Jerry

 

[RA_pierce]

Hey Ken... they also sell Reflective Tape for automotive a site safety use...

I wonder if you really need to cut up a sign...

Jerry

I was just going to mention that.

You can buy it... or steal it from traffic cones.

 

[Switch]

The beam that crossed my eye...
looked just like a...
focused laser beam.

Definitely NOT low power.

LarryDFW

It has to be scattered.If it would just reflect a beam back then all the signs would look like mirrors from whatever angle.

Also diachi, they do reflect back at the source, but your eye is not the source, so if you hit it with the laser at a 30 degree angle as compared to the direction of your eyes you will get most of it shining back at the laser and less in your eyes. Of course, at large distances this would be negligiable .

 

[Flaminpyro]

just buy the reflective tape at a contractor supply store in your town. you can stick it on stuf and like the man said , light it up from far away.


peace Pyro

 

[Kenom]

I've tried the tape and such.. Not as effective as those green signs. The green sign are a product of 3m and are something like 90% reflective or something like that. and I mean it's like the difference between night and day. The reflective tape is like turning on a single 5mm led. The signs are like turning on the stadium lights.

 

[Mr_Lazo]

You're lucky (from a laser use perspective) to live in a wide open area.

I live in the middle of a city, not quite a mile from an international airport, so I have to be careful who I let "hold" my lasers (lest I have Sir Five-Oh knocking on my door for a plane spotting).

QuackMaster, though you kind of glossed over it, you might want to look into putting together a liquid sky; it's really easy and portable, and it would look great with a little of that naturally occuring fog you were talking about.

But you do make a good point, as far as "what else?":thinking: