Safety glasses for alignment

[SkibberBent]

Hey guys.

I just started out with lasers and are planning to build some projectors myself. I want some safety glasses for when i need to align the beams and i'm unsure what kind of glasses to get. For now i will be working with lasers in the <500mW range (200mW 450nm, 200mW 638nm & 100mW 532nm). Do i have to buy 1 pair of glasses for each wavelength or can i get RGB glasses that still allows me to see what i'm doing? If i have to get glasses for each wavelength then what do i do when i have to get 2 or more beams with different wavelengths to align?

I have been looking at these: http://noirlaser.com/nd1.html? But i'm worried that i wont be able to see anything with those on. Can you guys give me some pointers as to what i should get?

Thanks a lot!

[HankLloydRight]

I just went through the same thing, I'm also a beginner. I have a 2W RGB rig I'm building, and the blue and green are really bright, so it was hard to align without flashes of light reflecting off of other parts towards my eyes. So what I did, and is my suggestion to you is to hook up the projector to some control software (Quickshow, Beyond, or any other) and just dial down the power to 20%, or "just visible enough" to do the alignment... and then periodically increase it to check the alignment, and then bring it back down to adjust.

I'm sure more experienced guys will chime in, but that's my suggestion.

[neskusen]

I just went through the same thing, I'm also a beginner. I have a 2W RGB rig I'm building, and the blue and green are really bright, so it was hard to align without flashes of light reflecting off of other parts towards my eyes. So what I did, and is my suggestion to you is to hook up the projector to some control software (Quickshow, Beyond, or any other) and just dial down the power to 20%, or "just visible enough" to do the alignment... and then periodically increase it to check the alignment, and then bring it back down to adjust.

I'm sure more experienced guys will chime in, but that's my suggestion.

I'm a beginner myself but before an experienced user chimes in I'll comment.
I don't think this is a good idea for 2 reasons:
1) 20% is with most diodes not safe and just visible enough might still not be eye-safe. Obviously you want to help a fellow user but I think this is a dangerous thing to suggest.

For the sake of your own eyesight I suggest to not adjust lasers like this anymore, specular reflections from brass, aluminum, copper parts and optics are dangerous, nothing close to diffused reflection.
I hope you haven't scarred your eyes, sometimes you can't tell because it hits in an rea where there are no nerve receptors and a dark spot in the vision is filled with random data by your brain. Not trying to scare you but this is true.
You are probably fine but I'd suggest to test your eyesight anyway: http://www.laserpointersafety.com/tr....html#selftest

2) I think if you dial down the power, you change the beam profile and shrink it, so if you align like this it might look perfect but then at full power you will get beams clipping among other things.

As for the goggles, I've ordered two for different wavelengths (one protects from red, the other from green-blue wavelenghts) for one reason: so I can see everything else easily thanks to all the incoherent light in the room. You are right this won't protect from the final alignment of the 3 beams and still help you see the points/beams though.

[HankLloydRight]

2) I think if you dial down the power, you change the beam profile and shrink it, so if you align like this it might look perfect but then at full power you will get beams clipping among other things.

That's exactly why I said dial it back up to 100% at times to check the full alignment.

Like I said, it was a suggestion. I also looked into RGB goggles, and either they're real cheap and don't work well, or phenomenally expensive. So in the lack of affordable and functional glasses, what would you suggest someone do?

[neskusen]

That's exactly why I said dial it back up to 100% at times to check the full alignment.

I misunderstood then.

I also looked into RGB goggles, and either they're real cheap and don't work well, or phenomenally expensive. So in the lack of affordable and functional glasses, what would you suggest someone do?

Certainly not risk your eyesight because of lack of options. I'm sure someone here can suggest a good RGB goggle.
Last resort ghetto option, attach a red wavelength google on top of a blue-green wavelength google, or the opposite way.

[SkibberBent]

Thanks for the replies. :-)

I am using TTL lasers, so i can't turn down the output power. Thats why i want some glasses, but i'm not sure if i can see anything if i buy glasses for all wavelengths. Maybe someone have been in this kind of situation before?

[Melgarh]

HD webcam on a stand right next to the alignment point and live stream it to your PC? Hope the suggestion doesn't sound silly but with manual focus you could technically see how it is pointing.
Basically replace your eyes with any valid technology to display the result on a device that is not harmful.

[mixedgas]

There is one company that sells broadband OD3 goggles for laser projection, but they are 450$ a pair..

Steve

[neskusen]

Serious question, won't an OD3 red glasses on top of OD3 blue-green glasses work?

[mixedgas]

That is a can of worms. First of all, overlaying the glasses usually means neither pair is properly worn, leaving gaps in the protection. Second of all, the visible transmission thru combined pairs will suck, as they use dyed plastic or glass filters with wide adsorption bands.. So your blue green goggles will pass orange red. Your Red goggles will pass blue green. You end up with very little overlap. If you only have a few percent of visible light transmission, the Goggle may be a greater hazard then the laser..
!
Besides, you should be able to design your projector in such a way to trap most stray beams.. Align with the projector at waist level, and use masking and trapping to block the strays..
Good analog lasers dial down to next to NO power...

~
The RGB filter of choice is a UVEX P1e07 , how inexpensive you can obtain it is between you and UVEX.....
~
http://www.uvex-laservision.de/en/la...filters/p1E07/

!
Steve