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Building an artificial sun that looks realistic [video]

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Re: Building an artificial sun that looks realistic [video]

#101

Post by corty »

crazygringo wrote: post #45
npunt wrote: post #33

Seems like this idea could scale very well with more LEDs of lower wattage, like a local dimming array in TVs. That way 1. heat would be more evenly distributed reducing the need for large heatsinks 2. smaller fresnel lenses could be positioned much closer to the light reducing thickness 3. with a lot of LEDs there'd be a less noticeable grid at the edges of each fresnel lens from chromatic aberration. I'd totally bu…

Do they make "directional" or "angled" Fresnel lenses? Because you also really want the light to come out of the vertical window at something like a 45° angle downwards. The physics of it should be fine, I've just never heard of them being manufactured. And then just add a translucent blue diffusing layer on top. It seems highly commercializable.

There are flat sheets of prisms, that do what you need there. You probably know them from pictures you had as a child that change what they display depending on the angle you are looking under.

Re: Building an artificial sun that looks realistic [video]

#102

Post by joshspankit »

dzhiurgis wrote: post #95
gruez wrote: post #60

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).

I’m confused by this comment. There is evidence that Vit D deficiencies have all sorts of health impacts, and that supplements raise in-blood levels. What other evidence is needed?

https://www.bulletproof.com/supplements/vitamins-minerals/vi... (11 scientific references linked at the bottom)

Re: Building an artificial sun that looks realistic [video]

#103

Post by ecef9-8c0f-4374 »

ecef9-8c0f-4374 wrote: post #90
jankotek wrote: post #77

Earlier quoted context omitted.

It is much easier to take broken lcd screen and remove diffuser. https://m.youtube.com/watch?v=8JrqH2oOTK4

the point of the parabolic reflector/fresnel versions are the parallel rays

maybe I should look at things first before commenting ..

Re: Building an artificial sun that looks realistic [video]

#104

Post by findthewords »

bukka wrote: post #4

I'm curious if the lack of heat in the lightrays will ruin the immersion of sunlight? Perhaps couple this with an IR heatlamp to add the real feel of sunrays hitting your skin?

Yes, patio heaters are very cheap. Such an infrared emitter would have been a very easy addition to this project, at the cost of doubling the power draw.

Re: Building an artificial sun that looks realistic [video]

#105

Post by dan-robertson »

joshspankit wrote: post #102
dzhiurgis wrote: post #95

Earlier quoted context omitted.

FWIW there's not evidence vitamin D supplements have any health impact (asides from crickets).

I’m confused by this comment. There is evidence that Vit D deficiencies have all sorts of health impacts, and that supplements raise in-blood levels. What other evidence is needed? https://www.bulletproof.com/supplements/vitamins-minerals/vi... (11 scientific references linked at the bottom)

Most things related to vitamin D are just correlation. If you are weak and frail you may not get out much and won’t have so much vitamin D. That doesn’t mean giving you vitamin D will make you strong. I heard that most studies don’t show benefits from vitamin D a supplements but maybe I’m wrong.

Re: Building an artificial sun that looks realistic [video]

#107

Post by i6ruce »

amai wrote: post #106

This is not new. See this video from 2014: https://www.youtube.com/watch?v=aJ4TJ4-kkDw This light is sold by https://www.coelux.com/ . They might also hold the patents on this technology.

Yeah, but it show how you can do it by yourself and not spend 30k on manufactured one.

Re: Building an artificial sun that looks realistic [video]

#108

Post by joshspankit »

dan-robertson wrote: post #105
joshspankit wrote: post #102

Earlier quoted context omitted.

I’m confused by this comment. There is evidence that Vit D deficiencies have all sorts of health impacts, and that supplements raise in-blood levels. What other evidence is needed? https://www.bulletproof.com/supplements/vitamins-minerals/vi... (11 scientific references linked at the bottom)

Most things related to vitamin D are just correlation. If you are weak and frail you may not get out much and won’t have so much vitamin D. That doesn’t mean giving you vitamin D will make you strong. I heard that most studies don’t show benefits from vitamin D a supplements but maybe I’m wrong.

Sounds to me like what you heard could be easily proven/disproven by reading some studies.
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