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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]

#21

Post by whoisburbansky »

kossTKR wrote: post #17
whoisburbansky wrote: post #15

Earlier quoted context omitted.

Seconding this, although I only bought one giant 14k lumen corn cob, since I didn't have a good spot to put the second. Anecdotally, they've been great at staving off my usual post-lunch slump. Right around the same time as I got it, though, I started waking up much earlier naturally, without an alarm clock (shifting from ~9AM natural wake up to more like ~6AM). I'm careful about turning the corncob off no later than…

Sounds very interesting - i am currently in Europe and can see that the price is about 350 usd, and you can get versions from 3000 (warm) to 6400 kelvin (sunlight?). What kelvin did you choose, and how large is your room? Did you put something in front of the lamp to diffuse? Looking forward to get out of the lockdown slump! :)

The one I got is 5k kelvin, which was advertised as sunlight as well, and is about as cold as I can take. If I had to buy it again I probably would get something slightly warmer, tbh. I've got a lampshade on it that diffuses the light at the cost of attenuating it a bunch, but it hasn't lessened the effectiveness as far as I can tell.

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

#22

Post by csnover »

vimota wrote: post #14

If you're too lazy to build something like this out but like the idea I highly recommend bright LED lighting for the day (explained here: https://www.benkuhn.net/lux/ ). I bought two ~7000 lumens LED corn bulbs and have noticed a huge shift in energy levels from having a brightly-lit room in dark PNW days. I put together a bunch of resources when I was researching buying some here: https://www.notion.so/vimota/LED-Wo…

I did something similar to this but was turned away from using random bulbs off of Amazon since most of them lied about their product performance (advertising peak wattage of all the LEDs and then not driving them at max power), safety certifications (fake UL and ETL markings), and in several cases I could not even find valid business licenses where the companies claimed to be incorporated. I need light for the darkness of winter but not at the expense of burning down the house.

Instead, I ended up buying a string light[0] and a box of 1600lm daylight LED bulbs[1]. Installation sucks, but once the whole thing is up, it’s nice that the light is distributed throughout the room instead of coming from a single point source. It was (at least at the time) cheaper than buying corn lights—and as a bonus, you can swap back the bulbs that come with the string light for party lighting.

[0] https://www.costco.com/feit-electric-48'-led-filament-string...

[1] https://www.costco.com/feit-electric-led-100w-replacement-br...

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

#23

Post by vimota »

kossTKR wrote: post #17
whoisburbansky wrote: post #15

Earlier quoted context omitted.

Seconding this, although I only bought one giant 14k lumen corn cob, since I didn't have a good spot to put the second. Anecdotally, they've been great at staving off my usual post-lunch slump. Right around the same time as I got it, though, I started waking up much earlier naturally, without an alarm clock (shifting from ~9AM natural wake up to more like ~6AM). I'm careful about turning the corncob off no later than…

Sounds very interesting - i am currently in Europe and can see that the price is about 350 usd, and you can get versions from 3000 (warm) to 6400 kelvin (sunlight?). What kelvin did you choose, and how large is your room? Did you put something in front of the lamp to diffuse? Looking forward to get out of the lockdown slump! :)

My diy lamp shade has been wrapping parchment paper around the LED corn bulb (making sure to leave space for airflow so it doesn't overheat!). It's not perfect but it helps diffuse the light and make it less intense to look at.

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

#24

Post by rnabel »

filleokus wrote: post #18
vimota wrote: post #14

If you're too lazy to build something like this out but like the idea I highly recommend bright LED lighting for the day (explained here: https://www.benkuhn.net/lux/ ). I bought two ~7000 lumens LED corn bulbs and have noticed a huge shift in energy levels from having a brightly-lit room in dark PNW days. I put together a bunch of resources when I was researching buying some here: https://www.notion.so/vimota/LED-Wo…

I was looking into this last year, but couldn't really find anything similar here in Sweden (or anywhere in the EU). I wonder if there are some regulation here banning ultra high lumen bulbs? The closest match have been on semi-sketchy sites, where they've been ≈ 300 euro for 10k lumen... How expensive are they in the US?

I also looked into this and ended up being successful when searching for photography lights and corn cob LEDs. Corn cob bulbs at 40-60 Watts each are cheap (~20USD in the UK), provide ~4K lumens each, and 2-3 are bright enough to get to daylight levels. Would highly recommend if you want to see whether it makes any difference, and/or which colors temp works best.

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

#25

Post by konjin »

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?

The main issue is the blue scattering. If you can get away with pre-scattering the light before it hits the dish adding an IR lamp is no issue since you're using a parabolic mirror which has no diffraction. I have no idea if it 'feels' right doing that though.

For full immersion you would also want a number of different light sources since leds are have very narrow spectra.

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

#26

Post by jameslk »

vimota wrote: post #14

If you're too lazy to build something like this out but like the idea I highly recommend bright LED lighting for the day (explained here: https://www.benkuhn.net/lux/ ). I bought two ~7000 lumens LED corn bulbs and have noticed a huge shift in energy levels from having a brightly-lit room in dark PNW days. I put together a bunch of resources when I was researching buying some here: https://www.notion.so/vimota/LED-Wo…

I actually purchased the 35,000 lumen corn bulb mentioned in the post you linked to. It's actually really big and awkward to place and has kind of a loud fan. Currently I have it propped in a corner since it's too heavy to be held by anything that I have to support it. But it will light up a bedroom just as much as a window of sun will. It doesn't look entirely like sunlight, but for the price, it does an adequate job.

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

#28

Post by lelandbatey »

konjin wrote: post #25
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?

The main issue is the blue scattering. If you can get away with pre-scattering the light before it hits the dish adding an IR lamp is no issue since you're using a parabolic mirror which has no diffraction. I have no idea if it 'feels' right doing that though. For full immersion you would also want a number of different light sources since leds are have very narrow spectra.

The method proposed in the video already accounts for the narrow LED spectra by using lights that have excellent color reproduction (the part where he recommends a CR rating of 95%+)

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

#29

Post by PTOB »

rococode wrote: post #2

In a sci-fi future where people are making long journeys on spaceships I can imagine rooms decked out with these to mimic a natural day/night cycle and outdoor spaces. I remember first seeing lights like these a couple years back before from CoeLux ( https://www.coelux.com ), iirc theirs are very expensive though. Awesome that this guy managed to DIY one!

I looked into it for a client's commercial building. $40k each for parts only.

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

#30

Post by tootie »

rococode wrote: post #2

In a sci-fi future where people are making long journeys on spaceships I can imagine rooms decked out with these to mimic a natural day/night cycle and outdoor spaces. I remember first seeing lights like these a couple years back before from CoeLux ( https://www.coelux.com ), iirc theirs are very expensive though. Awesome that this guy managed to DIY one!

Especially if they emit the UVB light we need for Vit D production
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