2 ms·

Like you alluded to, but I think it's good to be specific, dim != weak[1]. There could be a lot of infrared coming out of a cheap laser device you cannot see. O

by Klinky 15y ago

Like you alluded to, but I think it's good to be specific, dim != weak[1]. There could be a lot of infrared coming out of a cheap laser device you cannot see. Obviously no one should do your demonstration unless they have the laser device fully vetted by someone who knows what they're doing. What was the milliwattage of the laser in your demo? I imagine 5 - 10mw is too dangerous, so it must have been really low power. [1] http://www.wired.com/wiredscience/2010/08/laser-pointer-hazard/ http://www.wired.com/wiredscience/2010/08/laser-pointer-haza...

Natsu 15y ago
That's a very good point. It was a long time ago, so they used the old system back then and labeled it as a class IIa: https://en.wikipedia.org/wiki/Laser_safety https://en.wikipedia.org/wiki/Laser_safety I don't remember a wattage offhand and I no longer have that laser pointer, but I think it was under 1 mw. But there are other safety factors that can come into play, too. Mostly, it's a matter of how much energy is focused onto how small of an area for how long, not to mention how much of that energy is visible, which is why it's good to know the safety classifications. There are dangerous lasers, after all and it's a bad idea to be cavalier about eye safety around those. In fact, I saw some just the other day in operation at MakerBench, where they were cutting plastic. The paper covering the plastic was getting set on fire... not something you want shining into your eyes. EDIT: Reading your article scares me a little. I had a laser from a reputable supplier with an accurate classification. If they're selling crap with no filters like that nowadays, that's a lot more worrisome. People might own a laser that's a lot more dangerous than it's marked as being. Some lasers, especially cheap, "dim" green ones may not be what they're marked as. If it's cheap and not red, it's probably frequency doubled IR, so, yeah, beware....

by Klinky 15y ago

Natsu 15y ago

That's a very good point. It was a long time ago, so they used the old system back then and labeled it as a class IIa: https://en.wikipedia.org/wiki/Laser_safety https://en.wikipedia.org/wiki/Laser_safety I don't remember a wattage offhand and I no longer have that laser pointer, but I think it was under 1 mw. But there are other safety factors that can come into play, too. Mostly, it's a matter of how much energy is focused onto how small of an area for how long, not to mention how much of that energy is visible, which is why it's good to know the safety classifications. There are dangerous lasers, after all and it's a bad idea to be cavalier about eye safety around those. In fact, I saw some just the other day in operation at MakerBench, where they were cutting plastic. The paper covering the plastic was getting set on fire... not something you want shining into your eyes. EDIT: Reading your article scares me a little. I had a laser from a reputable supplier with an accurate classification. If they're selling crap with no filters like that nowadays, that's a lot more worrisome. People might own a laser that's a lot more dangerous than it's marked as being. Some lasers, especially cheap, "dim" green ones may not be what they're marked as. If it's cheap and not red, it's probably frequency doubled IR, so, yeah, beware....