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I tried making artificial sunlight at home

victorpoughon.fr

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Re: I tried making artificial sunlight at home

#91

Post by anthk »

sheepscreek wrote: post #34
jclarkcom wrote: post #19

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…

“Virtual Sun” looks really cool. How much does one cost today? Say if someone wanted to buy a single piece or a few (2-3).

Hope Oracle doesn't sue them somehow ;)

Re: I tried making artificial sunlight at home

#92

Post by firju55 »

alejohausner wrote: post #41

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…

If the metric you're looking for is most accurate spectrum including deep red, near and far infrared (heat), then a good old incandescent filament light is the most efficient device. Not LEDs.

Re: I tried making artificial sunlight at home

#93

Post by wtallis »

brcmthrowaway wrote: post #25
Const-me wrote: post #23

> the main thermal issue when scaling up would be the cooling of the power supply itself, not of the lamp If I would be scaling up that device, I would consider an ATX power supply. These are relatively large and typically include an active cooler inside, but they can easily supply hundreds of watts at 12V, often have an on/off switch on the back, are relatively inexpensive (at least unless you need much more than 50…

Could you wire them in parallel for more watts

At that point you might be better off getting a power distributor from an old server that was already designed to operate off redundant 12V power supplies. But you wouldn't want the server PSUs themselves due to the tiny loud fans.

Re: I tried making artificial sunlight at home

#94

Post by Vox_Leone »

This project is fantastic, but you also deserve congrats for the 'Lens Maker'[0].

"If we have a compound optical system made of a series of lenses, mirrors, etc., we can treat each optical element as the layer of a neural network." Kudos.

[0]https://victorpoughon.github.io/torchlensmaker/

Re: I tried making artificial sunlight at home

#95

Post by cowfarts »

brcmthrowaway wrote: post #25
Const-me wrote: post #23

> the main thermal issue when scaling up would be the cooling of the power supply itself, not of the lamp If I would be scaling up that device, I would consider an ATX power supply. These are relatively large and typically include an active cooler inside, but they can easily supply hundreds of watts at 12V, often have an on/off switch on the back, are relatively inexpensive (at least unless you need much more than 50…

Could you wire them in parallel for more watts

[dead]

Re: I tried making artificial sunlight at home

#96

Post by reaperman »

fouronnes3 wrote: post #81
reaperman wrote: post #79

I saw "artificial sunlight" and thought "oh wow I'd love to see the spectrogram of the lighting solution this person came up with". I was disappointed to merely see "CRI 95+". https://www.youtube.com/watch?v=lH_owRxupC0 This is great video on the shortcomings of "CRI" - it explains in detail CRI, CRI extended, TLCI, TM-30, and SSI. Brightness and color temperature are only two small parts of lighting - more people sh…

Do you have any insight on how to take spectroscopy measurements at home on a <1k€ budget? And how to select an LED manufacturing supplier when CRI is often the only thing available on the datasheet?

Starting points for first question: Look into i1Pro (later models of the first generation), which can be had for $200-400. Combine with some free or $99 Windows/Mac/Android software [0] [1].

Second question: It is still too hard even to find CRI for most offerings. It's pretty much a "buy, test, return the ones you don't like" situation. If independent reviewers start publishing spectrograms and making YouTube/etc videos, perhaps the industry will move forward some day.

0: https://www.argyllcms.com/doc/instruments.html#i1p2

1: https://rmimaging.com/spectrashop_brochure.pdf

Re: I tried making artificial sunlight at home

#97

Post by reaperman »

jclarkcom wrote: post #19

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…

I'm very impressed that Innerscene provides LM-63 data for your artificial skylights. Is there any chance you'd be open to providing Spectral Similarity Index scores for your skylight? I think it would really differentiate your product and show how much your company cares about quality.

Re: I tried making artificial sunlight at home

#98

Post by dekhn »

Projects like this are a great demonstration of just how far hobby projects can go today by exploiting some fairly recent innovations. In particular, designing a custom lens geometry and having JLC manufacture small runs cheaply is especially impressive; and of course, what you can get out of a modern LED is just absurd.

Re: I tried making artificial sunlight at home

#99

Post by reaperman »

izuchukwu wrote: post #88
sberens wrote: 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/

Had the chance to see one of these in person - did not believe you could achieve “daylight indoors” before I did.

If you have a chance to chat with the staff again, I notice their marketing language says "Nearly perfect spectrum matching with daylight" - but they don't publish a Spectral Similarity Index. They only claim a (relatively low) CRI of 90+.

Edit: In other materials, they claim a very high CRI of 95+. Also the advertised wattage is sometimes 400W, other times 500W.

Re: I tried making artificial sunlight at home

#100

Post by fouronnes3 »

dekhn wrote: post #98

Projects like this are a great demonstration of just how far hobby projects can go today by exploiting some fairly recent innovations. In particular, designing a custom lens geometry and having JLC manufacture small runs cheaply is especially impressive; and of course, what you can get out of a modern LED is just absurd.

I agree, thanks for underlying that point. I did not intend to write an ad for JLCPCB, but honestly I kinda did. I feel like it's deserved praise because the service is really great. Low volume custom PCBs with assembly service and 5 axis CNC with a minimum order quantity of 1 is game changer for prototyping. Combined with a software first approach to design with tools like build123d, the flexibility of 3D printing and 5 axis CNC, and the addictiveness of the high dopamine feedback loop of software dev starts to bleed over to hardware dev. Shipping delay is the last hurdle.

About the lenses, I did consider injection molding during design, and one supplier even quoted me for $20,000. So yeah, very glad for JLC!

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