Safety Goggles / Shields

[Pitts]

HI..

Anyone point me to a good thread or info on the correct selection of safety goggles/ face shield and how to choose the correct OD, alignment etc etc.
Is there 'one pair' that can cover the whole range R+G+B.. if not how do you handle the situation with an RGB projector. I presume there must be an answer.
Thanks guys
Ray NZ

[Laser Ben]

There is not to my knowledge a pair that can cover all the RGB wavelengths. You need to wear 3 pairs or be very careful.

[carmangary]

I can say this: don't get the 650nm sport elite goggles from Wicked unless you don't want to see the beam at all. The 532nm sport elite goggles are pretty good, though.

[Laser Ben]

You must have a pretty dull saw in your avatar because it isn't cutting anything!

[Jem]

Hi Ray

See this thread...

http://www.photonlexicon.com/forums/...ptical+density

There's some really useful information in there. You will most likely need two pairs of goggles/glasses as a minimum. One for the 473/532nm and one for the 660ish nm range. I use OD3 as these allow me to see a nice faint 'dot'. The Optical density you require will depend on the power of the lasers you are using. Mine are...

200mw 473nm
200mw 532nm
470mw 660nm

In my personal opinion having an OD that is too high is as bad as having an OD that is too little. Too high and you don't see anything therefore you are tempted to lift them off to see what's happening, and too low you are potentially exposing yourself to too much light.

I use the Bolle Goggles, they are about £120 UK a pair, I would be very careful about buying from a trusted source otherwise you may be buying nothing more than some nice coloured lenses that don't have the necessary optical properties. Yes, I agree they are quite expensive BUT it's no good spending all that money on nice pretty lasers if your eyes are too damaged to see them !

Cheers

Jem

P.S. Don't forget that you really ought to be minimising the risk of eye exposure first. There is a school of thought that says you shouldn't have to rely on safety goggles at all if you've taken all neccesary precautions to minimise the risk first. Personally, I don't subscribe to this point of view and believe it's better to be safe than sorry. But hey, we're all entitled to our own opinions

[stanwax]

There was some talk on alt.lasers a long time ago about the CVL makers Spectronica who sell a range of goggles. They are very well priced but dont seem to directly quote the ODs - unless you wanna work it out from thier graph.

Link here
http://www.spectronika.com/Safety.html

anyone had any experience with these?

Rob

Ps they are not the most stylish gogs around but are ideal if you want that 'mad scientist' look

[carmangary]

haha. Yea, the saw is a bit of a joke. There used to be a coach at Univeristy of North Carolina. He wasn't very good and lost a lot of games. After each loss, he would say "We just have to keep sawing wood and get better." He said that for 5 years and things never got better. Anyway, someone on the UNC football forum made that avatar and a bunch of us started using it. I'm the only one still using it as far as I know. The coach was fired after last season.

[clandestiny]

one of the best places for laser eyeware and safety info is rockwell laser industries-
www.rli.com

[Pitts]

Hey thanks for the help guys..

I have been doing a bit of looking around into safety glasses/ goggles. It is quite a subject.
I think the point that safety glasses can be bad if they are so absorbant at your laser frequency such that you cannot see the beam could lead to a bad decision to have a sneaky look !!! ouch !
Now IF I understand this correctly ( please tell me if I am wrong).
Lets say I have a 1500mw green (cause thats whats on its way
right now... drool .. ).

OD of 1 means I will still 'see' 150mw ?? ouch
OD of 2 means I will still see 15mw ?? ouch
OD of 3 means I will still see 1.5mw ?? now below class 2 levels
OD of 4 means I will still see .15mw ?? (can you see this anyway?)

Now in my ignorance would I not want a pair of OD3 to OD4 specs as I am not going see anything if go for OD 5 -6 ??
If I cant see the beam maybe I might take a chance and screw my eyeballs !

Here's an idea, given that someone said 'be careful' not bad advice, but if you dont have safety specs its a big "be Careful". Might not be a bad idea to wear an eye patch over one eye. ( bit like an electrician keeps one hand behind his back. Kinda not 'proper' but better than doing nothing.) better a one eye laserist than a blind one.
I dont intend to risk it.. I'll spit the money and get the glasses its just which OD and which VLT %
Thanks

Ray NZ

[buffo]

It depends on what you want your goggles to do....

If you want to be able to see the beam with the goggles on, then the OD 3 goggles are probably what you're looking for. Just understand that a DIRECT HIT with those googles is going to be bright as hell, and will be most uncomfortable. (You probably won't damage your eyes, though you might see spots for a few seconds.)

On the other hand, if you want complete protection for your eyes, go ahead and get the OD 4 goggles, or even higher. You'll still be able to see the spot the laser makes on the wall, even with the googles. But a direct hit won't hurt nearly as much. (It will be very hard to see the beam, however.) OD 6 is not out of the question at all. In fact, you might want to go even higher...

As an example, I have a pair of OD 11 goggles that I've used with my 35 mw argon. That makes the power that comes through the googles something like .35 pico-watts. Yet I can still see the spot the laser makes on the wall.

Bottom line: The human eye is incredibly sensitive to light. It actually has the ability to detect SINGLE PHOTONS, but in reality it takes about 4 to 6 photons for the brain to acknowledge a flash of light. (But the rod cells really will react to just one photon!) So you can use higher density goggles and still see what you're working on.

Adam