Live data from Hacker News

I tried making artificial sunlight at home

victorpoughon.fr

61–70 of 243 posts

Re: I tried making artificial sunlight at home

#61

Really neat, thank you for posting. I took a different angle when trying to figure this out - my goals were high spectral similarity to the sun, high brightness, adjustable warmth, and low cost. The existing lower-cost solutions people have posted about end up with high brightness, but the lights are evil. I ended up with a photography light that's /alright/. It's not nearly as bright as I want, and I can't automate…

[deleted]

Re: I tried making artificial sunlight at home

#63

This is super cool, and a great project. As someone more on the software side as well, I’m inspired to take on something similar. But more importantly, as someone who rented a windowless room for a year, I would have loved to make a smart light like this to wake up to in the morning.

> windowless room

Thankfully that's illegal where I live. I'm even tempted to suppress my own work here, because I don't want it to be used to unlock new levels of dystopic housing.

Just kidding, thanks for the feedback!

Re: I tried making artificial sunlight at home

#65
post #54

Very cool. I do think the DIY perks version just pops a little nicer but it could also be the photography of the project. But the firm factor if your project is much nicer as well. I think both projects would be better suited for different needs so again very cool. If you had lots of space the diy perks would be the way to go. If you only have a thin wall or ceiling then yours would be best. All in all thanks for pos…

It's partly the photography but definitely the reality as well. Mine is only 0.03m², the DIYPerks parabolic reflector is 1.13m² :)

One of my goals was to explore the feasibility and scalability of a refraction based design.

Re: I tried making artificial sunlight at home

#67

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…

> So these lamps may look like sunlight, but they’re missing some crucial wavelengths. Which means they're also not going to give me a tan... bug, or feature?

Tan is the other end of the spectrum (UV)

Re: I tried making artificial sunlight at home

#69
post #60

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…

Yep, that was my first assessment. Cant call it sun without NIR.

Can't call it sun without gravitational confinement nuclear fusion either.

Re: I tried making artificial sunlight at home

#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 looking at them, so you can either buy ones from which you trust the manufacturer or do what I did and build a cheap optical spectroscope using a raspberry pi with a small camera attached, a spectroscope lens, and some python code. I'm sure there are guides you can find with a quick web search if interested in making one.
Post reply on HN