placing a digital camera close to the laser head

[Gary Hair]

I have a hard time believing the beam is focused enough after traveling 8"+ back to the cover to etch the glass

I believe it could happen, but I believe that it would have to be the "perfect storm" - the right material, the right speed, power, angle, etc. It's "possible" but not likely to happen on a regular basis. I also doubt you could reproduce the circumstances without some serious trial and error.

I'm not willing to risk my eyesight on that low probablility but I'd take a chance with my camera.

Gary

[Darren Null]

One nay-sayer coming up

I have been experimenting with CO2 lasers for many years and haven't yet been burned. Not even close.

The thing about retinas, is that you only have to be unlucky or wrong once. I always wear goggles for door-open stunt engraving. No other precautions...the rest of me will heal.

[Dave Johnson29]

Hey first nay-sayer,

Good point Darren, I wear glasses to see so in effect they would be my first line of defense. But goggles would be a good idea if you don't need glasses, I should have mentioned it. BUT, check my beam reflection experiment for more fun.

OK, call me one-eye-Billy-9-fingers-scar-face

I gotta get a real job, too much time on my hands.

[Darren Null]

I don't know whether glasses would stop the beam, or just focus it better. The goggles I have, you could get a pair of glasses inside...$50 on eBay and they were manufactured in Israel; specifically for the CO2 laser spectrum...can't remember any more details.

[Dave Johnson29]

I don't know whether glasses would stop the beam, or just focus it better.

It's just heat Darren, it would start to melt the lens but as Dan has said, that is a looong way for the beam to travel focused enough to do any damage. However, I believe it is all moot after the beam reflection experiment I posted.

I have 7-1/2" adjustment under the focus point for my table and dropping just two inches the beam has diverged enough to not mark paper. I think bouncing back to someone's face is a long stretch. The beam is already at the point of diverging at the point of focus or just beyond. I cannot see a reflection refocusing the beam. I have been wrong before and no doubt will be again though.

The thing is if a person feels better wearing the protection then by all means do it. Freak stuff can and does happen.

[Frank Corker]

Well it's not my camera, go for it, then post the results.

[Dan Hintz]

I don't know whether glasses would stop the beam, or just focus it better. The goggles I have, you could get a pair of glasses inside...$50 on eBay and they were manufactured in Israel; specifically for the CO2 laser spectrum...can't remember any more details.

The material glasses are made out of is quite opaque to the far-IR wavelengths of our lasers, hence the reason we use ZnSe lenses instead of standard optical glass. Your glasses would stop it without issue.

Your $50 eBay goggles could be replaced with a $5 pair of work glasses from Harbor Freight... acrylic, same issue as glass.

[Darren Null]

Your $50 eBay goggles could be replaced with a $5 pair of work glasses from Harbor Freight... acrylic, same issue as glass.

Ah well. To be honest they were overkill; they are for the metal-cutting kilowatt lasers where specular reflections can be a real problem. And they're designed so nothing gets in at the edges. Might be $45 wasted, but I really enjoy having binocular vision and it seems like a small price to pay to know for sure.

[stan kern]

So i get the idea that if you don't bypass the switches and you're pearing through the plexi view window your eyes are protected even if you're following the arc---correct or should one not look at it.
i'm always checking the burn and thought the view wndow protected the eyes

[Darren Null]

The plexi stops much of the specular reflections from the laser, so you're not going to lose your sight from watching it. That said, there's quite a lot of light in there...like arc-welding, but less so. I look at it, but don't stare at it, if you see the difference.

[Dan Hintz]

Don't treat it like your favorite telly program, more of an amusing Geico commercial, in other words...