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In case anyone reads this and gets excited enough to buy one, realize fresnel lenses are actually dangerous. It's almost like keeping some turpentine soaked ra
by awakeasleep 11y ago
In case anyone reads this and gets excited enough to buy one, realize fresnel lenses are actually dangerous.
It's almost like keeping some turpentine soaked rags in a cardboard box. Sort of kidding. The point is, you can have the lense somewhere you think is safe, but the angle of the sun changes throughout the year and one day six months later rays of light hit it. Or you have kids that don't think that way, and they leave it somewhere.
Even as a fully aware adult, it's counterintuitive, because you'll be trying to take it outside and accidentally burn yourself, or set it agains something while you're getting ready, not realizing the lens was born ready and doesn't care about your plans. You always have to carry them in a sheathing material. Your brain expects something like that to have an off switch.
They're cool, but you should probably keep them in an opaque sheath in a gun safe, and leave it alone when you're drinking.
- Natsu 11y agoThe article provides ample evidence to support your claims, given how many items on their list of things burned are people.
- userbinator 11y agoThe power of the Sun is definitely something to be respected... and since it's basically free, makes you wonder how much more of it could be harnessed to do other useful things. https://en.wikipedia.org/wiki/Solar_furnace https://en.wikipedia.org/wiki/Solar_furnace
- superuser2 11y agoInteresting. I work I a campus theater that has a lot of fresnel lenses in storage. We're careful with them because they're expensive glass, but have never thought of them as hazardous. There's no (direct) natural light anywhere near where they're kept, though.
- trhway 11y agoif only somebody gave the same advice to the "death ray" buildings architect - Vinoly. > but the angle of the sun changes throughout the year and one day six months later rays of light hit it. almost exactly word for word :) http://www.theguardian.com/artanddesign/2013/sep/06/walkie-talkie-architect-predicted-reflection-sun-rays http://www.theguardian.com/artanddesign/2013/sep/06/walkie-t... "The developers have blamed the problem on "the current elevation of the sun in the sky," a position Viñoly seems inclined to share. "When I first came to London years ago, it wasn't like this," he said. "Now you have all these sunny days. So you should blame this thing on global warming too, right?""
- erpellan 11y ago"the lens was born ready and doesn't care about your plans" gave me a good chuckle, thanks!