Yes, for a short period of time. Typical goggles have optical densities in the order of 3, reducing that 20 watts to 20 mW or less. Not exactly safe, but it makes the difference between definite damage and probable recovery.
Such powerful beams do melt through goggles though - i've tried 1 watt of 445 and that took a bit over a minute to chew through. But if it even provides a few seconds of protection, you'd be likely to get out of harms way in the 20 watt scenario.
If you look at the beam it looks more like a spotlight when they're shining it on it something. I don't think they fully collimated it to a point source though it still is a laser. That would mean the power density is speard out and it's nowhere near as bad as a 20 W green DPSS or a 20 W Ir diode. Still not wearing googles is a bad idea.
It looks like a fairly broad blue beam to begin with in any case, not sure about the divergence. The fact that the light source is a laser (assembly) doesnt really change all that much - its not safe to look directly into a kilowatt halogen spotlight, or into a cars highbeam up close for that matter.
Eventually it all comes down to power density, and lasers are not the only way to greatly exceed eye safe levels. Looking straight into the sun with a pair of binoculars will blind you just fine, the only difference is that banning the sun is a difficult matter
Then again, you've got that woman in, where... Spain? Who claimed ownership of the Sun itself, and legal process was kind of torn up since claiming the ownership of fukkin' Sun isn't actually against any laws or regulations.
One would think there's reasonable amount of implication that human stupidity does not reach that far. In our case, 1 AU.
But as Einstein said, human stupidity is infinite.
Back to the topic though, as beam appearing very wide - My guess is that they didn't extract diodes as themselves, they just took the assembly out of the projector and powered it as such, with maybe a few modifications to the collimating assembly, as diodes are knife-edged and the focused to a point with a large lens, to be used further in the projector's lightpath.
So maybe they just focused that and called it a day.
Yes, for a short period of time. Typical goggles have optical densities in the order of 3, reducing that 20 watts to 20 mW or less. Not exactly safe, but it makes the difference between definite damage and probable recovery.
Such powerful beams do melt through goggles though - i've tried 1 watt of 445 and that took a bit over a minute to chew through. But if it even provides a few seconds of protection, you'd be likely to get out of harms way in the 20 watt scenario.
Typical goggles are ment for full protection and are OD 5 or higher. Typical plastic based EN207 rated goggles can take 10^6W/m^2, or 1W/mm^2. Those have a rating of D L5.
Glass filters do better they can have ratings of D L6 or even DL7 for some IR goggles. Coating based filters can have a rating of D L8. That's 1kW/mm^2. But expect anything more than the standard plastic based goggles to be VERY expensive.
I was just considering the plastic ones as that is what most people here use. They may be able to take 1W/mm2 just fine, but its only a matter of time before the lenses start to melt from the absorbed energy.
I was sort of impressed by the performance of relatively cheap goggles in that regard: The dye never gave, it took physical destruction of the glasses (or plastics?) in order to get a beam through.
Even glass would have this problem though: With levels as high as 1 MW/m2, it would not take all that long to melt a pane of glass even if the protective dye in it were perfect. The only way around that would be a reflective coating, which is not that easy to produce considering it has to work from all incident angles.
"One would think there's reasonable amount of implication that human stupidity does not reach that far. In our case, 1 AU."
If you consider that the path the earth travels completely around the sun, if the claim for ownership was made and the resolution of that claim takes more than half the time as one complete orbit the actual distance would be 2 AU plus the width of the sun.
So it's more than twice as bad as you thought !
In my humble opinion, goggles are only necessary when dealing with laser POINTERS or the moving output of laser scanners at high power.
Your average large lab laser is NOT going to be pointing around everywhere, and will generally be pointed at a chunk of charcoal or something non-reflective that wont burn. There's little to no risk of accidentally hitting something reflective, because you're not pointing it around everywhere. Even with mirrors that create a fixed beam path (like in a projector) you know exactly where them beam is going, and it's not going to be pointed around all willy nilly.
There comes a point where safety glasses could actually be dangerous. I know that I sure as hell wouldn't want to put my arm (or any other body part...) into my 168 beam running full blast (10W) because I couldn't see the beam.
I really do apreciate that many of you are making a serious leap towards safety, which is awesome, but I've seen a few posts lately where people are being a tad bit ridiculous about it as well.
These are people who might get lasers banned because of their ignorance.:scowl:
at 0:46 , no safety goggles while working with high powered laser diodes (extracted from C@s1o projector)
In the united states at least, people have forgotten than it is not the governments job to impose regulations that restrict the rights of the people to bear property. (Not to say you cannot or should not face consequences for your ACTIONS)
The fact of the matter has always been, it is not the governments job to keep you safe. It is YOUR JOB to keep yourself safe.
The fact that government regulations as retarded as banning lasers becomes neccesary goes to show you how far society has degraded. Personal responsibility has been traded for a desire and dependence of enforced standards to which all must adhere. People no longer want to be responsible for themselves, and they demand therefore that the government must protect them.
And this is how we loose rights.
It is the governments job to keep you safe only as far as diplomatic/political areas are concerned. Their job is to administrate and provide the framework for a lawful society and to coordinate the operation of the nation and its military.
It is the police's job to find and apprehend violators of the law. They are a reactionary force, therefore they are not meant to keep you safe either.
The only person who can keep you safe is you. By being responsible and aware. But I have no doubt people would rather just "let the government handle it" And thus a Ban
I believe that most of the regulars on the forum are safety conscious. At least to an *acceptable* degree.
If one is going to operate a laser outside, and there is a *reasonable* expectation that the laser will not hit anyone's eyes, an aircraft, etc., or that there will be an accident, then fine. One doesn't need to wear safety goggles *every moment* that a laser is turned on or *under ALL circumstances* when a laser is operating.
There is a ... "weird" ... trend lately in many posts, almost like a kind of borderline hysteria. This kind of thing happens.
In my *opinion*, there is nothing in that video that would lead to the banning of lasers... at least due to lack of safety goggles.
IF lasers are going to be banned, it will *probably* NOT be over safety goggles!
It will be due to the immature jerks who point lasers at aircraft, people, animals (except certain insects... I admit to murdering insects), cars, *law enforcement officials*, etc., all because they think that it is "funny".
In one soccur/futbol -loving country IIRC they got banned shortly after a player was shot in the eyes while doing a pentalty kick and missed.
It will happen in the USA if idiots keep up their stoopid acts or if terrorists or demonstrators use them against police or to do harm to pilots during landing or take-off. And even then there will be millions of handhelds out there for those idiots & A-holes to buy so the ban will not effect them in any way whatsoever.
