Ask HN: Why are there so few artificial sunlight or artificial window products?
The demand for "natural light" in homes and offices is very high, and higher than the availability of actual daylight. And there seems to be a pretty feasible way to create a fake window (a light panel that mimics sunlight through a window), using LEDs and a fresnel lens. There's no shortage of videos around showing how to DIY such a thing, such as https://www.youtube.com/watch?v=8JrqH2oOTK4 and https://www.youtube.com/watch?v=GDeEuzKXCH4
So, why can't I find many such products for sale? There are a couple of high-end companies like https://www.coelux.com/, but where's the mass market stuff? Is there an opportunity being overlooked here, or am I just missing something?
169 comments
[ 3.1 ms ] story [ 56.1 ms ] threadThe FDA does not regulate light boxes, so caveat emptor.
[1] https://www.mayoclinic.org/diseases-conditions/seasonal-affe...
So I think what is needed is actually carefully dosing with full spectrum.
I find this point of view so rude, tone deaf even.
"caveat emptor" only applies if you personally believe humans are entirely responsible for their own actions and can't possibly be manipulated or scammed by others. That, or you think this is likely (and it is) but you simply don't care about these people and think that this is the market correcting for "dumb consumers".
Or maybe you think the laws of the land define how we should behave to one another? Anything not made explicit by "the law" is thus meant to be ignored? Not your problem?
I'm sorry, it's just the sort of thing some one who benefits from the lack of regulation would say. It sounds biased - like you're trying to justify some venture of your own that is also "unregulated, so caveat emptor".
Let me guess, cryptocurrency enthusiast?
Anyway I say all this because there _are_ better arguments against government regulation. But caveat emptor is just saying "fuck government regulation, it doesn't let me screw people over as much". You might convince more people if your do a bit of research (and maybe don't assume everyone simply agrees with caveat emptor - this is the tone deaf bit).
My own personal theory is that there is a health epidemic related to lack of sunlight exposure from most people being indoors. And so in my fantasy future cities that I build in my head, there are ways that actual natural light is delivered without being blocked by windows, such as carefully monitored full spectrum and/or UV lighting.
Another related issue is the concept of a virtual window that you can see out of. I think this will also be a future trend, since windows increase heating requirements and again don't provide the key UV component of light. Also, for the majority of history, inexpensive cameras and displays did not exist.
So what I suggest is virtual windows that are thin OLEDs and follow the person to give them a different virtualized view of outside. Or using some light field or multiview technology. Along with full spectrum lighting. And not entirely related but I think it would be best in most areas to standardize on airtight construction, mechanical ventilation and energy/heat recovery ventilators.
All the inside offices have sky lights, the outside offices have windows facing out and down (due to the offices above. I’m told there are no offices without daylight in the building, but I’ve been to the basement and they must mean the above ground floors.
I’m not sure how high you can build that or how difficult it is to heat, and it has lots of light but attenuated through windows which you were against.
But I wonder if we could build a modern day Hanging Garden, where each floor has a balcony, and a series of skylights allow some light through into an atrium, or series of atriums, so those who choose to stay inside still get indirect light, and some tropical plants.
But if I am reading this then maybe those atriums would provide the full spectrum light. It sounds like a really good architectural concept.
If you're worried about over-exposure, I suspect you could socially engineer people by making some routes in the building as fast or faster by going out and back in.
A small amount of UV exposure is necessary for some processes, including Vitamin D production and a few others.
The tricky part is that it is very widely known how dangerous UV is, and people with an outdoor lifestyle can easily overdo it, but at the same time there is an increasing portion of the population that spends almost ALL time indoors (except when they are on vacation) and gets close to NO UV exposure normally.
This almost total lack of exposure to UV can be especially problematic due to high latitude, winter, or even slightly high latitude and darker skin tones.
That's taking a very narrow view of what "benefits" exist. You don't need UV for the general pleasant feeling of good light.
That’s tough to do without either reabsorbing a lot of the light you created, or creating a large box to contain the light source.
One of the interesting DIY designs I’ve seen uses a surplus satellite dish, silvered, with an LED array at the focal point. The reflected light of the mirror is mostly parallel, but your light source is now 20+ inches deep.
I spent some time instead thinking about indirect light, like an artificial clerestory. Never did build anything though. When I moved I had plenty of natural light so I stopped trying.
Most lights are point sources with radiating rays. But the sun is so far away it appears collimated.
An example from DIY Perks YouTube channel [0].
[0] Building an artificial sun that looks unbelievably realistic. https://www.youtube.com/watch?v=6bqBsHSwPgw
It's a cool technology feature and a beautiful experiment and short film but not exactly easily attainable to the general public.
If you make a similar system with a cheap 100 watt LED you're not going to get the same results.
There's a thing called a Light Shelf, in which instead of mounting top-to-bottom blinds on a window, you install a shelf a distance below the top of the window, and a blind below it. The shelf is sized and placed so that no direct light gets into the room. Instead the light passing through the window is incident on the top of the shelf, and bounces onto the ceiling. This not only creates more hours of indirect sunlight (nobody ever prioritizes cycling the blinds to optimize for daylight), it also moves more of that light into the center of the room.
I have one window that's a tough size and location for blinds, and the time of day when the light hits me in the face is pretty close to the time when a light shelf would work.
The higher end of LED is slowly getting there. The measurement one should be looking for there is CRI ("Color Rendering Index"). The sun has a CRI of 100. Any lightsource above 90 to 95 CRI is (to my experience) indistinguishable from daylight. The best stuff there currently is are (of course) the Skypanels by ARRI for laughable 6800 USD per panel (film equipment is expensive as usual).
Blasting a 2.5 kW HMI lamp ("Hydrargyrum medium-arc iodide lamp") trough a window from the outside is a good emulation of daylight. So good in fact that the poor souls shooting films inside will have their bodies in confusion as they exit the room and realize in horror that it is dark outside.
The electrical bill of anything emulating the sun is no joke tho.
Over the last few years a ton of players have entered the film lighting space, with many offerings exceeding Arri's color rendering for far cheaper. Yuji LEDs or iFootage for example make some of the most accurate lights at 98+ cri.
The film industry will still go for Arris for other reasons, but at home we have lots of options nowadays.
Amazon listings will always claim ridiculous cri numbers, try to find a 3rd party measurement. https://indiecinemaacademy.com/complete-led-color-database-c....
https://youtu.be/qCyKdIgRVTk
That's just terrible drivers - likely an unisolated AC with a single coil. Flicker is trivial to defeat sacrificing the power factor (just add filtering caps). Overall there is nothing hard about using constant driven high-freq (over 30KHz, so no sound interference, either) LEDs.
Side note: in the days of home video calls, you can tell how many have terrible lights as the flicker is visible on the even camera.
The decent LED fixtures are designed to be a single unit, e.g. near ceiling light, dimmable w/ remote/blue tooth. Unfortunately, not possible to replace parts of them, and if they are poorly built - also overdriven. OTOH, they are trivial to repair with some electronics background - often times, the driver is replaceable entirely.
LEDs need to stay cool (below 60C) to have prolonged life - say 40K hours to stay at 80% brightness. That means large heatsinks, enough space to dissipate the heat.
While not impossible - the LED driver is a switch mode power supply, most of them would be universal one taking 90V-260V with rather variable frequency. What dimmers do - they chop the sine wave, normally that would not affect too much the driver (aside made them hot or require more bulk capacitance, which they lack) - so they have to know that the sine wave was chopped and react by reducing the duty cycle, reducing the brightness of the LEDs. That complicates the driver, however if you don't keep the LEDs at full brightness and they are not hot on touch - they should last.
The other option would be communicating through the zero cross of the sine wave, but I doubt very much it's the case.
The external dimmer is not a smart feature but more like necessity, unfortunately.
[1] https://www.osram.com/ecat/Professional%20LED%20lamps%20with...
...Interference with medical equipment (this lab I knew found out that their EEG malfunctioned when the new lamps were on...)
How would you instead check EMI - in general? (I am not a specialist in this area.)
This would be a really poor driver, effectively using the AC freq. and shutting off w/ each cycle/zero cross. Unfortunately, many are exactly like that. However - some cameras do have compensation for exactly this issue, and they may hide it.
>How would you instead check EMI - in general? (I am not a specialist in this area.)
Use an AM radio. (That would depend on the frequency and what not, but AM radios are a pretty neat trick to check)
I miss the days of a restive wire shoved into the AC circuit.
Honestly I have no clue why LED light are so poorly built nowadays. There is absolutely no technical reason for it.
So I don't believe it's the LEDs that are the problem.
And yes, by modern standards they can suck some juice but even a large ARRI Skypanel only draws 1500W [2], which is similar to a small air conditioner.
[0]: https://www.bridgelux.com/
[1]: https://www.yujiintl.com/
[2]: https://www.arri.com/en/lighting/led/skypanel/s360-c#F0.00S3...
Sunlike LED elements are available in different formats around the world:
http://www.seoulsemicon.com/en/technology/sunlike/casestudy/
Why would you compare it to an air conditioner though? Those aren't equivalents. You need to compare it to an alternative light source. A bright LED bulb uses about 13W. You could have 10 of them and still be using less than 1/10 of the energy...
Normal indoor LED lighting is almost a rounding error on your electricity bill these days. Daylight simulation uses much more power.
Therefore a valid comparison is to measure it against other sources of light, and not air conditioners. But anyway, saying it's "only" 1500W is incredibly odd. If your goal is just to "get light" then using 115* more energy than a 13W LED bulb is completely stupid. I understand that you might want more light than one bulb gives you, but even scaling up to 10 bulbs you're still a huge margin away from a Skypanel.
If you're running an art gallery or a showroom where the quality, color, and coherence of the light makes a difference then it makes some sense. If you're at home and you just want 'some light' then it's utterly ridiculous to use that much energy.
I would definitely say that this is a false statement.
> If your goal is just to "get light" then using 115* more energy than a 13W LED bulb is completely stupid.
The goal is to get artificial sunlight. A 13W LED bulb doesn't do that. An air conditioner doesn't do that either.
However, it's nice to know how much power these lights use, so we compare them to other devices which use a similar amount of power. Air conditioners and space heaters use a similar amount of power.
> If you're running an art gallery or a showroom where the quality, color, and coherence of the light makes a difference then it makes some sense.
I don't think a SkyPanel makes sense in those applications. If you are just running an art gallery or showroom, get some ordinary high-quality lighting.
I’ve never seen behind the stained glass but am guessing they have warm light fluorescent bulbs (no heat) and something diffusing the light because it looks evenly distributed.
There are no windows on the outside of the building so it seems something you can set into a wall.
The issue is definitely the power usage. It’s not reasonable to dedicate that much power for the relatively minimal gain.
Also, CRI is a relatively poor measurement of color quality because it measures a very desaturated color palette. You can have two high CRI lights and they will still not match. There are newer color rendering indices like TLCI, SSI and TM-30 to account for this.
CRI doesn’t measure vibrant red very well and human skin has that red.
Light is the prime inputs to human sensing their world! It amazes me people can be so unaware of lighting conditions / problems, when that is how they do a vast majority of these sensing of the world.
https://pubmed.ncbi.nlm.nih.gov/21675035/ https://www.nature.com/articles/s41599-019-0341-7
And it’s not simply being aware or not. We aren’t all born with the same senses. I can spot extremely minute color variations on tests but I have never been able to tell small differences in smell no matter how much I try.
I read an OP question, and was like, meh there must be something out there.
Then I read your answer, and was like, ohhhh this makes total sense. Of course you can't have equivalent of THE SUN for $50 and consuming couple of watts per day.
But what I would like to have is indirect light. E.g. point the lights to the ceiling and have the ceiling illumate the rest of the room. Not only is this less efficient in terms of electricty (but there isn't really a way around it) but it AFAIK also impacts the CRI depending on what material the ceiling/mat is made of.
Any insights here?
[0] - https://www.independent.co.uk/news/world/americas/amazon-men...
For rest of the country the main concern is the shorter days - meaning you can easily go to work before sun comes up and leave work just as sun is going down. But during working hours there is plenty of light even if the day is cloudy since snow is very reflective.
I see the main problem with the designs OP posted that they are just LED panels mounted on a wall. You don't get the same feeling of being in the sun when the light is not directional. You might as well just have one of the "bright light lamps" on your desk that have been sold for decades to combat "sunlessness".
I used to live in an apartment with huge windows, west-oriented, and no other building close by, and I still went out and bought a big ass LED light for working from home in winter. It made a huge difference to my mood.
And trust me, even overcast days bring light. It simply isn't as bright as you desire. Lots of folks would rather have more light when it is cloudy. It definitely isn't going to compare to a month of 4-hour-long days with the sun staying low in the sky. Further south, I've seen cloudy days brighter than a sunny day in December where I*m currently living.
It might have broken through at some point when I was inside, but it was raining every single day.
Some days, the moon provided more light (as you say, because of snow reflection) than the sun.
Those can be some very depressing days ... weeks ... months.
I'd welcome some sort of automated, artificial light source at my home office during those five months.
There are 29 average sunshine hours in whole December - less than in Stockholm. That means that even if you have 8 hours of "daylight" in a day, less than one hour is when you see the sun.
Sure, it’s not a market of millions, but that wasn’t my point. If you’re prone to seasonal depression, you’ll want a daylight lamp. Thankfully, those are available!
Similarly my office has some small spaces that are perfectly sized for taking calls or having 1-on-1 meetings, but to depressing to sit in for more than an hour since there are no windows. A fake window is not a window replacement, but would make them nicer places to sit for small amounts of time.
If you want one, you can build one following the video above. The result is quite stunning. I've never seen anything like it.
https://www.youtube.com/watch?v=8JrqH2oOTK4
The one above is an easier build that takes up less space.
Every home I’ve had (including starter apartments and a basement bedroom) was well lit by natural light. Offices have been more problematic, but decision makers generally aren’t effected by it, almost universally having window offices. Factories (at least the few I’ve been at) are often heavily lit with natural light via skylights.
That being said, there is probably a market in the higher end office design market and possibly for basements, like in the I like to make stuff video.
I think the problem then is “how do I design around/with this product.” Designers and builders roughly know how to use existing lighting products. How do you utilize this artificial sunlight product in your lighting design. Those wall mounted led windows look cool, but I’d be super annoyed if my desk were facing them. The fresnel lens looks nice in that accent position, but if it got in people’s eyes or strained them it’s a problem.
Finally, the two examples you showed are using stock led panels. As others have said, you can get some interesting effects from them, but I strongly suspect you’ll end up in the “uncanny valley” with that sort of lightning- the spectrum and consistency just isn’t quite right, the light doesn’t feel “warm” enough in the infrared, etc.
Try it out- see if you can get a lighting setup you and others love. I suspect the product is restricted to the high end currently because it’s genuinely hard to get right in a way that doesn’t feel cheap or artificial. But I’d love to be proven wrong.
Owners of old houses, particularly in inner urban areas. Lots of old houses had small windows, to keep heat in. Or have been overshadowed by taller buildings being built nearby. Or both.
Source: am one.
> think the problem then is “how do I design around/with this product.” Designers and builders roughly know how to use existing lighting products. How do you utilize this artificial sunlight product in your lighting design. Those wall mounted led windows look cool, but I’d be super annoyed if my desk were facing them. The fresnel lens looks nice in that accent position, but if it got in people’s eyes or strained them it’s a problem.
I'm imagining the market is people improving an existing room, perhaps even renters. So, designers and builders wouldn't really come into it.
So I can't really agree on it being well-lit, despite having actual windows on two sides of the apartment. Not to the point of complaining, but if only your kitchen (small, no table) and bedroom are on the west and you live in the northern hemispher... let's just say from a lighting perspective I've had 2 better apartments before this.
[1][2]
The big market for these things is hospitals. They operate 24/7, and tend to have many windowless interior rooms. Both patients and staff lose circadian rhythm in such timeless environments.
[1] https://www.coelux.com/
[2] https://www.apartmenttherapy.com/artificial-window-36758108
It is a hard problem to solve technically. Getting collimated light in a compact space, not wasting a ton of energy while having high cri and the right color temp or emulating Rayleigh scattering. The higher end products are also pretty large.
If you work somewhere without windows (which I did for a while) and work 9-5 you basically never see the sun Monday to Friday.
Trying to generate sunlight that can fill a room like the sun is going to use a lot of power and generate heat. Also, the DIY youtube versions don't feel very realistic to me, it's probably a much harder (and expensive) problem to solve than just a fresnel lens.
edit: Watching another youtube video, it looks like the DIY versions are missing the "blue sky effect"
E.g.: https://news.ycombinator.com/item?id=32221087
A friend has the light tube in every room, I thought this was a good idea until I saw it. Everything was very cold and blueish, as if it was cloudy. I actually found it somewhat depressing.
We've done a lot of research on lighting in pursuit of building a better webcam (our main product). We found the lights on the market (i) aren't very bright, (ii) aren't smart in any way, and (iii) are way too expensive for the functionality you're getting.
Personally, I use a 100 watt LED corn bulb but it's not very pretty.
We're considering building a light as our next product. Imagine: a light that's super bright, adapts its color and intensity to the weather / time of day / other lights in your room. (If anyone has ideas here, please reach out!)
https://worldbuilding.stackexchange.com/questions/130769/can...
https://en.wikipedia.org/wiki/Light_tube
https://microsunlamps.com
They are specialty metal halide bulbs - and really work!
Seems priced for medical settings and high-end commercial kinds of projects.
You might also find Daniel Rybakkens work interesting:
https://www.danielrybakken.com/surface_daylight.html
http://www.danielrybakken.com/daylight_comes_sideways_files/...