Polarized lenses?

[Pontiacg5]

Alright, I know this is going to sound messed up but my green laser is too bright! I can't get pics of all of my laser beams because the green floods out the other colors. I tried using a polarized lens from a 3d movie to dim the beam but my laser just burned a hole in the thing. Is there anywhere to buy polarized lenses that will handle 125mW without melting?

Here is my 593.5nm by its lonesome, no smoke...

Here it is with my 5mW 635nm

And the green. Damn thing lights up the whole room!!

 

[kevinmassey]

Have the beam terminate on a matte black surface.

 

[Pontiacg5]

It is! It still comes out this bright.

I have a fairly long exposure time, the other two lasers won't show up without smoke otherwise.

 

[kevinmassey]

Hmm if you tried it outside you wouldn't have that problem. If your determined to shoot it inside you could let the green beam go through a slit in a doorway into another room.

 

[Pontiacg5]

I'll have to get a tripod and head outside, or I guess I could open the window and let it go outside too

 

[kevinmassey]

Make sure you post those beam shots once you get 'em!

 

[Pontiacg5]

I guess I could quit being cheap and get more fog juice, I could get some epic beam shots with some fog!

 

[kevinmassey]

I use incense. It's cheap, works great, and makes your house smell alright, but if you use a ridiculous amount like me you might want to keep it in the garage. It gets a bit overwhelming.

 

[Cyparagon]

Why not buy a cheaper green? Is $7 too much?

 

[Pontiacg5]

I could but the beam on this laser is so tight and nice I just want to scale the power back a little. I don't think a $7 dollar green will have a divergence like this one does.

Also, I would like a "power ring" that you turn to tone your lasers back for beam alignment and other random pointing experiments where you don't need 100+mW.

So nobody knows where to get a polarized lens or filter that wont burn?

 

[Wallydraigle]

How long is your exposure? You could try only leaving the green laser on for part of the exposure. That way it will appear less bright in the final image.

The thing is, even with high quality photographic polarizers, they still just use a thin polarizing film, which is applied to the glass in a couple different ways. I think you'd still end up ruining the filter with your laser, and these filters can be expensive.

 

[Justin]

Polarizers from 3D glasses are circularly polarized. Lasers, if they have a good polarization ratio, are linearly polarized. In short, those lenses won't do anything. You need to find a linear polarizer with a high damage threshold. However, if your laser doesn't have a good polarization ratio this still wont be very effective. I recommend getting a glass neutral density filter for attenuating the laser since this will work for almost all lasers regardless of orientation or power.

 

[Greenmechanic]

You need a ND filter of around 10-20% pass. The good ones are all glass and will not melt or distort the beam.
Surplus Shed has a wide selection of them for very good prices.
I'd get a few different % ones, that way you can fine tune your beam to the brightness you want.

 

[Cyparagon]

"fine" tune? unless you have thousands of filters, the tuning will be anything but fine.