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I tried making artificial sunlight at home

victorpoughon.fr

141–150 of 243 posts

Re: I tried making artificial sunlight at home

#141
post #39

Really cool! I'm working on a lamp that gives you daylight levels of light indoors (albeit no raleigh scattering and columnated light). On the bright side (pun intended), it's 50,000 lumens instead of ~4500. https://getbrighter.com/

500 watts! I won't need a heater any more if I turn one of these on. I had a 10k lumen led matrix lamp, but I found that it completely threw off my natural rhythm to sit under it for any length of time. It felt like it was perpetually early morning.

Re: I tried making artificial sunlight at home

#142

For me, the problem with this setup (and with most high efficiency LED lights) is the lack of red wavelenghts. Real sunlight has a substantial amount of energy in the very red end of the visible spectrum (700 nm) and also of course quite a bit in the infrared. These lamps have two spectral peaks: a narrow peak in the blue range, around 450 nm, a broader peak in the green, centered around 580 nm. That greenish peak fa…

What you want is at odds with energy efficiency and is therefore being made illegal https://blog.medcram.com/uncategorized/new-department-of-ene...

Again, another regulatory decision that makes a niche worse off overall....

Abuses of a carve-out aside, having a "Sunlight mimicking" exemption would solve this, with the added conditions that they have to actually stick to the EMF outputs of the sun to get this approval. The article itself does this with “General Wellness Lamps”.

Otherwise, the only non-reg way to solve this would be to find infrared & red LEDs and make the supplementary light sources yourself.

Re: I tried making artificial sunlight at home

#143

Very cool. I’m the CEO of Innerscene ( https://innerscene.com ) and we make a commercial artificial skylight that uses some of these concepts. Actually the coelux ht25 model is almost identical to what you made but using smaller lenses and more LEDs - however the effect they were able to achieve still isn’t that great, the sun looks like a giant orb and once you get a few feet away you can make out a sun at all. We s…

Not joking. Do these artificial sunlights help with the allergies? If yes and if it's not insanely costly I'd just try to get something like that for my bedroom during allergy seasons which most often coincides with no sun (winter, rain here). Even in those seasons when the sun comes out in its glory, the allergies (which mostly is my nose turning into an infinite source of salt water), which were driving me stark ra…

I would suggest you make sure you don't have any indoor mold. Mold in an apartment caused me problems some years ago. My understanding is that outdoor/natural mold is perfectly fine for most people (including me), but molds tend to incorporate whatever they consume into their spores, because molds prey on other molds so they try to arm themselves.

The problem is with manmade stuff like sheetrock, where the mold grows and then incorporates the binder chemicals into their spores, which are too small to see and yet get inhaled and then leech into our sinuses or whereever.

I've had problems in both work and home situations. I was tested and confirmed allergic; I don't think most people are, but it was rough for me. I'm always on the lookout for those water circles in drop ceilings; they're notorious mold colonies. Once a natural material stays wet for 12 hours, molds will begin to grow.

Just something you might be able to check off your list. Good luck.

Re: I tried making artificial sunlight at home

#144

Very cool. I’m the CEO of Innerscene ( https://innerscene.com ) and we make a commercial artificial skylight that uses some of these concepts. Actually the coelux ht25 model is almost identical to what you made but using smaller lenses and more LEDs - however the effect they were able to achieve still isn’t that great, the sun looks like a giant orb and once you get a few feet away you can make out a sun at all. We s…

Does this actually give you the same intensity as sunlight? Or well, close enough to it that the light can diffuse into the rest of the room? In my experience my 4000lm projector doesn't have anywhere near the intensity to properly approach sunlight.

Re: I tried making artificial sunlight at home

#145
post #78
post #70

I'd be interested in seeing the optical spectrograph of the LEDs. If you want to simulate sunlight you want a full-spectrum LED like a Samsung LM301 series LED which are popular in grow lights. Not all LEDs are created equal, and even the LEDs in many "grow" lights only show two sharp peaks at red and blue wavelengths. A full-spectrum LED will output colors across the visible spectrum of light. You can't tell by look…

This is covered by the CRI95+ value, note that the LM301 you mentioned only has a color rendering index of 70. Maybe it has predominant wavelengths that are relevant for plant growth, I don't know, but a CRI of 70 isn't impressive at all. For an accurate rendering of the suns spectrum you basically would like to simulate the spectrum of a blackbody radiator with a surface temperature of 5500°C minus the absorption ba…

Thanks for the insight. Most of what I know about LEDs, and specifically the LM301 series, comes from research I did prior to setting up a small indoor grow tent several years ago. It was a "spikey spectrum" precisely that I was trying to avoid. For growing Cannabis you do want spikes at red and blue, but better LEDs also emit a wider spectrum along with the spikes and that results in a better result. Having only spikes at red and blue alone works, but not as well. The lights I ended up buying had LM301H EVO LEDs with a CRI of 80 and were designed for a 2'x2' tent. You can also get LM301H LEDs with a CRI of up to 90, though. The lights I ended up buying only cost 80 BezosBucks at the time. I don't spend BezosBucks anymore, though, due to enshittification of everything Amazon, but I digress.

While they aren't designed for growing, and to use them would be a complete waste of $8k, I bet the Arri SkyPanel S120-C SoftLight with a CRI of 95 would do a fine job for growing. You weren't kidding about them being extremely expensive.

Re: I tried making artificial sunlight at home

#146

Earlier quoted context omitted.

there are companies that can do custom phosphor formulations for you to target a specific output. The minimum order quantities don’t make it practical for DIY but not too bad for a small startup. Our approach is to mix a bunch of different LEDs together to get the color and spectrum we want. Check out telelumen.com for an example that uses 16 chips. These are designed for researchers

I was doing something very similar to telelumen but given the variation in LED spectrum you could get off aliexpress in 2020 I could never hope to match their quality without tuning each led separately. Looking at the spectrum graphs for your lights I'm seeing the telltale phosphor coating spike for both warm and cool white leds. An understandable tradeoff, but with the brightness of monochromatic LEDs you can get to…

Yes, the more LEDs you mix the closer you can get to your target SPD but more LEDs also add cost and may not fit mechanically depending on how you are mixing them.

One other variable is energy efficiency, there are a lot energy codes around the world that limit how much energy you are allowed to use to light a space. In California for example it can be 0.6w per sqft. Sunlight is more like 100w/sqft so you end up having to optimize the spectrum for what humans can see and feel. I like to compare it with jpeg compression for light. In jpeg we throw away components you can’t see very well, you can do the same for light for an energy efficiency sake and maintain a close perceptual proxy.

We found 4 chips is a minimum bar for good light and use 5 for virtual sun - more info: https://www.innerscene.com/products/circadian-sky/CircadianS...

Re: I tried making artificial sunlight at home

#147

Earlier quoted context omitted.

I adore the lights by your company, though they seem to be incredibly hard to source in general except for high end architectural projects. I wish there was an easier way to order them directly for DYI inclined engineers willing to pay the price.

Yeah - channels can be a pain, reach out to me directly if you run into issues: Jonathan @ Innerscene

Super interesting! Any idea how you guys compare with https://getchroma.co/products/skylight ?

I love the idea of high quality lighting inside especially for my Chicago place.

Re: I tried making artificial sunlight at home

#149
post #144

Very cool. I’m the CEO of Innerscene ( https://innerscene.com ) and we make a commercial artificial skylight that uses some of these concepts. Actually the coelux ht25 model is almost identical to what you made but using smaller lenses and more LEDs - however the effect they were able to achieve still isn’t that great, the sun looks like a giant orb and once you get a few feet away you can make out a sun at all. We s…

Does this actually give you the same intensity as sunlight? Or well, close enough to it that the light can diffuse into the rest of the room? In my experience my 4000lm projector doesn't have anywhere near the intensity to properly approach sunlight.

Outside direct sunlight can be 100,000 lux. With one fixture if you are standing in the sunbeam you are more likely to be at 2000 lux which is a long way off. You can add more fixtures to increase the light you are getting. However it turns out that one of the most important parts of natural light is “melanopic lux” which comes from light centered around 490nm (blue), if you get more or this spectrum it can have the same effect as having a lot more light from a low blue Light fixture. (I.e typical 2700k bulb) Some info about this; https://www.innerscene.com/products/circadian-sky/CircadianS... There is now a lot of research that looks into how much of this blue light you need and architects are starting to incorporate this into Building designs.

Re: I tried making artificial sunlight at home

#150

Earlier quoted context omitted.

That's a good point, but not much I can do about that. Such a DIY project is limited to off the shelf LED suppliers. It would be cool to do such a lamp with both the high CRI and some infrared, also for heating (infrared lamps are a thing after all).

I don’t think manufacturers will make LEDs with strong deep-red emission. If they made LEDs that emitted lots of red light, they probably would have a peak in the red end of the spectrum. But since they’re not monochromatic single-wavelength sources like lasers, there would be a spread of wavelengths around that red peak, including substantial infrared emission. And that IR emission makes heat, and now you’ve created…

I'm just a customer of some their other products but... https://getchroma.co/products/skylight. (Of course as you know you're now drawing a ton of power for things other than lumens)
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