91–100 of 129 posts
Why do fresnel reflectors seem to be so hard to find? Seems like they’d be a good option here.
Do you mean just the lens? There's one in each of those old school overhead transparency projectors. Those should be easy to find. https://www.bhphotovideo.com/c/product/592006-REG/Dry_Lam_50...
A Frensel reflector doesn't led light through bit instead reflects the light. Basically the same idea as the parabolic dish, but as a flat sheet.
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Don't forget that the volume of the device has a cost too. The video shows the construction of a really really nice, but takes up the whole hallway outside that room. Most of the time you'd probably prefer to use your hallway for walking in. On the other hand, maybe your house has an attic above one of your rooms that; there will be a lot less opportunity cost to using up that volume.
Use Fresnel lenses with a shorter focal length and reduce the depth. It would be useful to start with a standard home-type window from, say, Home Depot, and build a unit about 120mm deep using multiple shorter focal length Fresnel lenses.[1] Then, in a basement or windowless room, mount some of these into a wall. Add curtains. Nice if your home office or workshop is in a basement. This has commercial applications. Ho…
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It's not really good enough: https://www.oscars.org/science-technology/sci-tech-projects/... Mixing violets and greens makes the spectral curve closer to that of sunlight. Again, without seeing it in person there is no way to know how much impact this has. Using a parabolic reflector however is the only way to go since you will not get diffraction or blocking of wavelengths.
Without going into the pdf report, the multiemitter doesn't look better than the blended phosphor.
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I had a room in an apartment that had no sunlight, and was lusting after CoeLux after it launched. Almost goes without saying, but the first to manufacture an affordable solution at scale would make a ludicrous amount of money, especially with much of the world in lockdown. Low dose UV light would also be a good addition.
Low dose UV light would also be a good addition. I'd also like a bit of optional IR so you get a tiny bit of that toasty sun feeling if you want it.
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Especially if they emit the UVB light we need for Vit D production
I thought the official advice was to get supplemental vitamin d through oral supplements, rather than through artificial UV lamps? https://www.nhs.uk/live-well/healthy-body/how-to-get-vitamin... >Using sunbeds isn't a recommended way of making vitamin D.
Interestingly I posted this 2 days ago but it dropped into the ether. Ever since I seen it I've become convinced something similar will be part of a future garden office I'm planning. With a IR panel heater to add the warming effect. I was also wondering about whether UVB could be incorporated by but frankly I'd be too chicken to mess with that.
I personally hate sunlight for indoor activity. It's just too intense for anything involves vision, reading, writing, looking at screen, etc.
Why do fresnel reflectors seem to be so hard to find? Seems like they’d be a good option here.
And I think they really could be a good option. Unlike the lenses, there would be no chromatic aberration with a reflector, right? Plus, you can set the focal length to whatever you want (taking practicality into account of course).
I might have to try it out...
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Don't forget that the volume of the device has a cost too. The video shows the construction of a really really nice, but takes up the whole hallway outside that room. Most of the time you'd probably prefer to use your hallway for walking in. On the other hand, maybe your house has an attic above one of your rooms that; there will be a lot less opportunity cost to using up that volume.
Use Fresnel lenses with a shorter focal length and reduce the depth. It would be useful to start with a standard home-type window from, say, Home Depot, and build a unit about 120mm deep using multiple shorter focal length Fresnel lenses.[1] Then, in a basement or windowless room, mount some of these into a wall. Add curtains. Nice if your home office or workshop is in a basement. This has commercial applications. Ho…
Turning Smashed TVs into realistic daylight panels: https://www.youtube.com/watch?v=8JrqH2oOTK4
Earlier quoted context omitted.
Use Fresnel lenses with a shorter focal length and reduce the depth. It would be useful to start with a standard home-type window from, say, Home Depot, and build a unit about 120mm deep using multiple shorter focal length Fresnel lenses.[1] Then, in a basement or windowless room, mount some of these into a wall. Add curtains. Nice if your home office or workshop is in a basement. This has commercial applications. Ho…
lenses cause chromatic abberations though, the red/yellow halo around the beam you see in his cheaper version at the end.
Earlier quoted context omitted.
I thought the official advice was to get supplemental vitamin d through oral supplements, rather than through artificial UV lamps? https://www.nhs.uk/live-well/healthy-body/how-to-get-vitamin... >Using sunbeds isn't a recommended way of making vitamin D.
FWIW there's not evidence vitamin D supplements have any health impact (asides from crickets).