Interesting...

Well my DX true 30 has heat issues, where it dims if kept on for too long. So i like to throw it in the freezer for a minute or so just to speed up the process. But I just recently left it in there for too long and got some interesting results. The dot was very dim, and when shined on my palm, looked like a dull red halo around the dim green dot. I looked at the halo with my camera and it was purple-IR. But when I moved the laser back, it was still focused the same around the dot. Isnt IR hard to collimate? Does low frequency IR look red, or was I seeing something else? I really need to go to bed, I have a final exam in my physics clas tomorrow, so ill play around with this tomorrow.

actually, its high freq ir that looks red.

You were seeing bleed over from the crystals being too cold That also is a fairly good indicator that you are lacking an IR filter in that laser...

Maelstrom said:

Isnt IR hard to collimate?

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It seems quite a few of the unfiltered greenies these days have pretty collimated IR beams, the divergence of the IR coming from one of my unfiltered greenies is around 2.5mRad.

Arghh... Do you guys think I need to get an IR filter or is the IR from a 30 not that bad?

Maelstrom said:

Arghh... Do you guys think I need to get an IR filter or is the IR from a 30 not that bad?

Click to expand...

i wouldn't worry about it

You don't need an IR filter IMO, if it is collimated you won't get any dangerous IR exposure unless you point the laser in your eye. And if you were to do that, I wouldn't be too concerned about the IR leakage because now you have a class IIIb green laser beam in your eye