Elevator pitch: Bring enough light to simulate daylight into your home and office.

This idea has been shared in Less Wrong circles for a couple years. Yudkowsky wrote Inadequate Equilibria in 2017 where he and his wife invented the idea, and Raemon wrote a playbook in 2018 for how to do it yourself. Now I and at least two other friends are trying to build something similar, and I suspect there's a bigger-than-it-looks market opportunity here because it's one of those things that a lot of people would probably want, if they knew it existed and could experience it. And it's only recently become cheap enough to execute well.

Coelux makes a high-end artificial skylight which certainly looks awesome, but it costs upwards of $30k and also takes a lot of headroom in the ceiling. Can we do better for cheaper?

Brightness from first principles

First let's clear up some definitions:

  • Watts is a measure of power consumption, not brightness.

    • "Watt equivalent" brightness is usually listed for LED bulbs, at least for the standard household bulb form factor. You should generally ignore this (instead, just look at the lumens rating), because it is confusing. Normally "watt equivalent" is computed by dividing lumens by 15 or so. (bulb manufacturers like to make LED bulbs that are easy to compare, by having similar brightness to the incandescents they replace, hence "watt equivalent")
  • Lumens output is a measurement of an individual bulb, but says nothing about the distribution of those rays of light. For that you want to be doing math to estimate lux.

  • "Lux", or "luminous flux", is the measurement of how bright light is on a certain surface (such as a wall or your face). Lux is measured in lumens per square meter. Usually, your end goal when designing lighting is to create a certain amount of lux.

    • Direct sunlight shines 100k lux (source for these on Wikipedia)
    • Full daylight (indirect) is more than 10k lux
    • An overcast day or bright TV studio lighting is 1000 lux
    • Indoor office lighting is typically 500
    • Indoor living room at night might be only 50

Side note: This scale surprises me greatly! We usefully make use of vision with four or more orders of magnitude differences in lux within a single day. Our human vision hardware is doing a lot of work to make the world look reasonable within these vast differences of amount of light. Regardless, this post is about getting a lot of lux. I hypothesize that lux is associated with both happiness and productivity, and during the "dark season" when we don't get as much lux from the sun, I'm looking to get some from artificial lights.

If you put a single 1000-lumen (66-watt-equivalent) omnidirectional bulb in the center of a spherical room of 2m radius (which approximates a 12' square bedroom), the lux at the radius of the sphere is 50. So now we can get a sense of the scope of the problem. When doctors say you should be getting 10,000 lux for 30 minutes a day, the defaults for home lighting are two orders of magnitude off.

  • Raemon's bulbs are "100W equivalent" which is ~1500 lumens per bulb. So he's got 36k lumens. If we treat this as a point source and expect that Raemon's head is 2m away from the bulbs, then he's getting 1800 lux, which is twice the "TV studio" lighting and seems pretty respectable. I haven't accounted for reflected light from the ceiling either, so reality might be better than this, but I doubt it changes the calculation by more than a factor of 2 -- but I don't have a robust way of estimating ambient light, so ideas are welcome.
  • David Chapman's plan uses three 20k-lumen LED light bars for offroad SUV driving, for a total of 60k lumens. But because the light bars aim the light at a relatively focused point on the floor, David estimates that most of that light is being delivered to a roughly 6-square-meter workspace for a total of 10k lux. The photos he shared of his workspace seem to support this estimate.

Other important factors besides brightness

Color temperature seems important to well-being. Color temperature is measured in kelvins with reference to black-body radiation, but you can think of it as, on the spectrum from "warm white" to "cool white", what do you prefer? Raemon's plan uses an even split between 2700K and 5000K bulbs. 2700K is quite yellow-y, 5000 is nearly pure white. In my experimentation I discovered that I liked closer to 5000 in the mornings and closer to 2700 in evenings.

And what about light distribution? Large "panels" of bright light would seem the closest to daylight in form-factor. Real windows are brighter near the top, and it is considered dramatic and unnatural to have bright lighting coming from the ground. Also, single bright point sources are painful to look at and can seem harsh. I think there's a lot of flexibility here, but I think my personal ideal light would be a large, window-sized panel of light mounted on the ceiling or high on the wall.

Also, color accuracy: LEDs are notoriously narrow spectrum by default; manufacturers have to do work to make their LEDs look more like incandescent bulbs in how they light up objects of different colors. Check for a measure called Color Rendering Index, or CRI, in product descriptions. 100 is considered perfect color rendering, and anything less than 80 looks increasingly awful as you go down. The difference between CRI 80 and 90 is definitely noticeable to some people. I haven't blind tested myself, and definitely might be imagining it, but I feel like there was some kind of noticeable upgrade of the "coziness" or "warmth" in my room when upgrading from CRI 80 to CRI 95 bulbs.

Dimmability? (Are you kidding? We want brightness, not dimness!) Okay, fine, if you insist. Most high-end LED bulbs seem dimmable today, so I hope this is not an onerous requirement.

Last thing I can think of is flicker. I have only seen flicker as a major problem with really low-end bulbs, but I can easily see and be annoyed by 60hz flicker out of the corner of my eye. Cheap Christmas LED light strings have super bad flicker, but it seems like manufacturers of nicer LEDs today have caught on, because I haven't had any flicker problems with LED bulbs in years.

Okay, so to summarize: I want an all-in-one "light panel" that produces at least 20000 lumens and can be mounted to a wall or ceiling, with no noticeable flicker, good CRI, and adjustable (perhaps automatically adjusting) color temperature throughout the day.

A redditor made a fake window for their basement which is quite impressive for under $200. This is definitely along the axis I am imagining.

I haven't mentioned operating cost. Full-spectrum LEDs seem to output about 75 lumens per watt, so if our panel is 20k lumens then we should expect our panel to draw 266 watts. This seems reasonable to me. If you leave it on 8 hours a day, you're going to use 25 cents per day in electricity (at $.12 per kWh).

Marketing and Costs

What do you think people will pay for the product? I have already put 6+ hours into researching this and don't have a satisfactory solution yet. I would probably pay at least $400 to get that time back, if the result satisfied all my requirements; I expect to put in quite a bit more time, so I think I could probably be convinced to pay north of $1000 for a really good product. Hard to say what others would pay, but I wouldn't be surprised if you could build a good product in the $400-1200 range that would be quite popular.

What about costs? Today, Home Depot sells Cree 90-CRI, 815-lumen bulbs on their website for $1.93 per bulb for a cost of $2.37 per 1000 lumens. This is the cheapest I've seen high quality bulbs. (The higher lumen bulbs are annoyingly quite a bit more expensive). To get 36k lumens at this price costs under $100 retail. Presumably there are cooling considerations when packing LEDs close together but those seem solvable if you're doing the "panel" form factor. There are other costs I'm sure, but it seems like the LEDs and driver are likely to dominate most of the costs. These are dimmable but not color temperature adjustable.

Yuji LEDs sells 2700K-6500K dimmable LED strips, also with 95+ CRI, at $100 for 6250 lumens (so a cost of $16 per 1000 lumens). This is 7x more expensive per lumen, but knowing that it exists is really helpful.

Promotion and Distribution

Kickstarter is the obvious idea for getting this idea out there. I would also recommend starting a subreddit (if it doesn't exist; I haven't checked yet) for do-it-yourselfers who want to build or buy really bright lighting systems for their homes, as I think there is probably enough sustained interest in such a topic for it to exist.

You can also try to get press. The idea of "indoor light as bright as daylight" is probably somewhat viral so I'd hope you can get people to write about you. Coelux got a bunch of press a few years ago doing this exact thing, but their product is so expensive that they don't even list their price on their website, but in articles about Coelux you can see people commenting that they wish they could afford one.

I do think the idea needs to be spread more. Most people don't know this is possible, so there's a lot of work you'll be doing to just explain that such a thing is possible and healthy.

Competition?

I don't think there's any relevant competition out there today. Coelux is super high end. The competition is do-it-yourselfers, but this market is far bigger than the number of people who are excited to do-it-themself.

Some have mentioned "high bay" lights, which are designed to be mounted high in warehouses and such, and throw a light cone a long distance to the floor. I am excited to try this and I will probably try it next, but I am not super optimistic about it because I expect it to be quite harsh. This is the one that Yuji sells, but you can find cheaper and presumably lower-quality ones on Amazon.

Part of my motivation for writing this blog post is to source ideas for other things that exist that could fill this niche. Comment here if you solved this problem in a way I haven't described! I'll update this post with ideas. If you start this company, also email me and I'll buy one and try your product and probably write about it :)

Building a Sustainable Business

If you put a bunch of research into designing a really great product and it succeeds but gets effectively copied by low-cost clones, you'll be sad. I am not sure how to defend this, and I think it is probably the weakest point of this business model; but it is a weakness that many hardware companies share, and a lot of them still carve out a niche. One idea would be to build up your product's branding and reputation, by explaining why low-cost clones suck in various ways. Another is just to give really good service. Lastly, if you avoid manufacturing things in China, maybe Chinese clone companies won't copy your technology as quickly.

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I'm one of the friends mentioned. Here's some more anecdata, most importantly including what I think is the current easiest way to try a lumenator (requiring only one fixture instead of huge numbers of bulbs):

I don't have seasonal depression, but after spending a winter in a tropical country, it was extremely noticeable that it's harder for me to focus and I have less willpower when it's dark out (which now starts at 4:15). I bought an extremely bright light and put it right next to my desk, in my peripheral vision while I work. It was an immediate and very noticeable improvement; I estimate it buys me 30-120 minutes of focus per day, depending on how overcast it is.

You can see a before-and-after here, although my phone camera's dynamic range is not good enough to really capture the difference.

Everyone who has visited my house since I got the lightbulb has remarked on how nice it feels, which I was initially surprised by since the bulb is 5600k and not particularly high-CRI.

My current setup is honestly kinda crappy (but still amazing). I'm working on a much nicer DIY version, but in the mean time, here's the stuff I bought:

  • 250-watt corn bulb (~= 40 60w-equivalent bulbs; $100)
    • This bulb has a pretty loud fan (~50db at close range); if you don't like noise, you can buy two of the 120-watt version.
  • this E39 fixture ($15)
    • the clamp is too weak to hold the bulb, but you can jerry-rig a support by embedding the socket into the styrofoam packaging that the light comes in :P
    • Also if you use this you'll need to turn it off and on by unplugging as there is no switch on the fixture.
  • these E39 to E26 adapters ($10 for 4)
    • buy if you want to put in an overhead light or traditional lamp
    • note that the bulb does not fit well in many fixtures because it is very large and heavy

(Amazon links are affiliate so I can see whether they are useful to people)

What if we just had brighter screens?

If it just needs to be brightness in the field of vision rather than brightness in the room, well, most of the time there's a (very large) screen dominating my field of vision.

I have now set my screen brightness in uncomfortable ranges. Having difficulty adjusting but feeling very awake. Will report back in a week, I guess.

I was considering projecting bright light onto the wall behind the screen (this would allow the light to be defused a lot, and it would be very easy to deploy, wouldn't even need to hang the thing, let alone make a power socket), but it occurred to me that having the backdrop be brighter than your screen tends to cause headaches.

I think this is likely to be orders of magnitude away from the kinds of things which have been effective for others (see e.g. this rough calculation on reddit)

Do you currently have SAD?

No and it's summer in my hemisphere anyway (but I spend a lot of time indoors)

What are you testing, then?

I am frequently afflicted with the kinds of drowsy depressive states that I would associate with a state of dormancy in a deep winter. I think I heard that brighter lights generally increase alertness and productivity. My current model is.. the mechanisms for determining whether the human is indoors and (therefore?) about to sleep are just very very crude. The model is also trying to account for the the CO2 concentration thing, which, last I heard we didn't have any other plausible evolutionary accounts for.

I used to work in the lighting industry, so here are some comments from an industry perspective.

There are several high-quality studies about how more light, and being able to control dimming and color temperature, can improve subjective well-being, alertness, and sleep patterns. It is generally accepted that you do not need to go to direct sunlight type lux levels indoors to get most of the benefits. Also, you do no need to have the brightest dim level on all the time. For some people, the thing that will really help is a regular schedule that dims down below typical indoor light levels at selected times, without ever dimming above typical levels. I am not an expert on the latest studies, but if you want to build an indoor experimental setup to get to the bottom of what you really like, my feeling is that installing more than 4000 lux, as a peak capacity in selected areas, would definitely be a waste of money and resources.

If I would want to install a hassle-free bright light setup in my home cheaply, I would buy lots of high-end wireless dimmable and color temperature adjustable LED light bulbs, and some low-cost spot lights to put them in, e.g. spot lights that can be attached to a ceiling mounted power rail. If you make sure the bulbs support the ZigBee standard, you will have plenty of options for control software.

If power rails with lots of ~60W equivalent bulbs lacks aesthetic appeal for you, then you could go for a high-end special form factor product like that from Coelux mentioned above. The best way to think about the Coelux product, in business model development terms, is that it is not really a lighting product: it is a specialised piece of high-end furniture. So if you want to develop a business model for a bright home lighting company, the first question you have to ask yourself is whether or not you want to be in the high-end furniture business.

By the way, the main reason why the lighting industry is not making any 200W or 500W equivalent LED bulbs that you could put in your existing spot lights is because of cooling issues. LEDs are pretty energy efficient, but LED bulbs still produce some internal heat that has to be cooled away. For 60W equivalent this can happen by natural air flow around the bulb, but a 200W equivalent bulb would need something like a built-in fan.

Thanks, this comment is really useful!

It is generally accepted that you do not need to go to direct sunlight type lux levels indoors to get most of the benefits.... I am not an expert on the latest studies, but if you want to build an indoor experimental setup to get to the bottom of what you really like, my feeling is that installing more than 4000 lux, as a peak capacity in selected areas, would definitely be a waste of money and resources.

Do you have any pointers to where I might go to read the latest studies?

For 60W equivalent this can happen by natural air flow around the bulb, but a 200W equivalent bulb would need something like a built-in fan

From the net I find that a typical 60W incandescent is 10% efficient, therefore generates 54W of heat within the light fitting. A typical 60W equivalent LED bulb draws 7.5W and is 90% efficient, therefore generates 0.75W of heat in the fitting. Therefore, for an LED bulb to generate as much heat as a 60W incandescent, it would generate 54/0.75 = 72 times as much light, and be equivalent to 72*60 = 4320W of incandescent lighting.

Since 60W incandescents do not need fan cooling (or even 150W, which I have used at home in the past), why would a high-powered LED bulb?

LED bulbs aren't made of tungsten and so cannot heat up to 3000+ degrees without taking damage. LED's are much more sensitive to heat and will burn out very quickly if not properly cooled.

A typical 60W equivalent LED bulb draws 7.5W and is 90% efficient

Where are you getting this number? As far as I know, the most efficient LEDs today are around 50% efficient.

Oh, somewhere on Google.

Check out our product, it's a far-cry from the $400 you mentioned but many times less expensive and thinner than coelux.

Check out a video here:

https://www.youtube.com/watch?v=XVV_-aB1jpg&t=57s

Some comparisons with Coelux: https://bit.ly/2YszzsO

We have done 7 years of research on this and just recently brought "Virtual Sun" to the market.

If you want to replicate a window, there is more than just lumens, CCT, and CRI. In order for your brain to really believe something is a window or a skylight, you also need:

1. Separate sun and sky light components. The real sun is very directional, by the time it reaches the earth the rays of sunlight diverge by only 0.5 degrees, have a much lower CCT than the sky, and a much brighter lux profile than the rays of light from the sky. Innerscene Model A7 outputs a rectangular sunbeam the diverges at less than 2 degrees and has a CCT of 4500K and is over 2500 lux at head level when sitting under it. Compared that with Coelux which has a 10 degree divergence angle. A7's sky changes from 3000K up to well over 10000K.

2. The illusion of infinite space behind the fixture. The LEAD building standard requires all rooms to have eye level sight lines to the outdoors. Psychologically a room with windows is much more comfortable to work in than those lit only by artificial light, part of this is that most people have some level of claustrophobia - ranging from very mild (but noticeable) to panic attack inducing. Being able to see outside elevates a lot of that. We invented a new 3d display technology that allows users to see a sun at infinity, rather than something painting on the surface so it looks like a portal, not a TV or flat surface. This turns out to be an extremely hard problem, and I haven't seen anyone else do it - even coelux's sun only appears to be about 20 feet away from you.

3. Variability in CCT and intensity. Artificial light is too static which creates monotony, we are used to a variety of light profiles from natural light because of the earths rotation and atmospheric effects. When the sun is obscured by clouds temporarily, the light in the room changes slowly but very significantly - there is more diffuse light and less directional light, the CCT gets warmer, and brightness in the room may go up or down depending on the cloud thickness. Similar the CCT of light the sky changes throughout the day because of the earths orbit and how much light goes through the atmosphere at different angles. Innerscene is able to replicate this and it makes a room feel "alive" and connected to the outdoors, combined with the 3D effect it is comfortable to work/live in a space with no real windows for long periods of time.

You can't comfortably work in a room where there is strong glare shinning in your eyes, which you would get if you buy random high powered LEDs and stuck them on your ceiling. From a perfectly diffusive light object like the sky there is no glare, but you will have glare from an unshielded light fixture unless it is well diffused or you have baffles that block the light which isn't going down. Getting the directional profile of light is very important in this respect. Because our sun is always at a high angle (30 degrees) it doesn't shine into your eyes directly and the sky portion of the fixture is perfectly diffused like the real sky.

(quick mod note: we normally delete first comments that are marketing a product. In this case it was surprisingly on topic and informative, but wanted to be clear that it wasn't precedent setting)

Hey wow, neat company and I’m glad you posted about it here!

Unfortunately, I get the sense that your product is up in the Coelux range of pricing, because you don’t list the price. I think a lot of people here are going to immediately dismiss it as an option given that we can’t easily figure out how much it costs.

Your marketing is also aimed at businesses instead of homes. Especially given that my post was about home lighting, do you have anything you can share about home applications of your product?

(BTW, I remember reading an article in the 90s from a tech mag - like Wired or something - about crack.com, although I had no idea what you did, but the notable thing that stuck in my brain from that article was “why on earth would anyone name a company after a horrifically addictive drug?” I’d be curious if you know what article I’m talking about and whether you have a link to it!)

regarding crack.com, funny you connected the dots! I was a co-founder of that company which made the video game "Abuse" back in the 90s. The story behind the name... originally we called the company Chameleon Software but found someone else was using that name and had to change it. At the time the internet was just starting out and we thought it would be cool to use a domain name to name the company. We went through the dictionary and decided to call it "Crack Dot Com", in those days we spelled out the whole thing. This is in part because at the time, there was a popular model for selling games called "Crack ware" because the first one is free, you get addicted and want to buy more :) We aspired to make addictive games and it was a bit edgy so I think it served us well. We didn't realize it then, but crack was one of the top 100 search terms on the internet because people were looking for software cracks so we got some free traffic (though ended up getting a lot of piracy!!) haha. My second company, which turned into Thinstall (now Vmware ThinApp) started out looking at how to stop software piracy by making desktop software have a small SAS component that was required.

Anyway, I wanted to get back to my computer graphics roots so I started Innerscene to research how to make 3D displays that look like windows (VR without a headset). Turned out to be a much harder problem that I expected but we have something really amazing now.

Was this an "Abuse" game that was distributed somehow by Bungie? If so I played that and have some fond memories. Hi!

yes! We published Abuse on DOS, Mac, and Linux (Redhat). When the company shutdown we released the code to the public domain so you can find it on many other platforms today including Windows or directly inside a browser ( https://playclassic.games/games/run-and-gun-dos-games-online/play-abuse-online/ ), and on iPhone/Android - though I find it hard to play on a mobile phone :)

Check out our product, it’s a far-cry from the $400 you mentioned but many times less expensive and thinner than coelux.

How expensive is it? Maybe there's some reason that you don't want an exact price in the comparison, but can you give a rough range?

As a rough guide, you can install 5-6 Innerscene A7 units in a project for the same price as one Coelux LC45 when you consider shipping and install cost.

Although understandably frustrating, we don't have public pricing for a few reasons.

1. Our product is generally integrated into a construction project where the purchasing process can be more complex. In such a project, you might have a General Contractor who subcontracts out the electrical work to an electrician who purchases from a electrical distributor - and each party has a mark-up they charge for the value they are providing to the price to an end-user can vary. In addition, for larger projects there can be lighting designer or lighting sales agency involved that help with design, code compliance issues, etc. Often these guys will work for free but charge a mark-up on the products they specify. For these, reasons you find most companies that sell lighting into commercial or larger residential projects don't have public pricing. Products you find at home depot or on amazon are usually commodity products where everyone has pretty much the same thing and companies compete mainly on price.

2. We work with partners who are allowed to set their own prices above our wholesale price to them. The amount of markup they charge will depend on how much of the above legwork mentioned above they take on, the size of the project, liability/warranty/service they take for the products they provide, etc. Depending on which country you are in, there could be import duties, shipping charges, etc. That being said, we do sell directly to customers for most of the world and happy to provide a quick price by email using info@innerscene.com

3. As we work on optimizing our products for higher volume and less expensive parts, we pass on cost savings to our customers - so our prices continue to come down year by year - for example A7 is >30% more affordable compared with A6 and it's a better product. However, many places on the internet are permanent and we risk of people seeing a price from 3 years ago and not looking any further because it's out of their budget.

How would very bright indoor lights handle the problem?

With the sun, it's already very far away (relative to the size of a room, or even the size of the whole earth), so light intensity doesn't vary much as we move around - stays basically constant. But in a house, you'll sometimes be 10X further from the light source than other times - so the light will sometimes be 100X brighter than other times. (I don't know if other people have this problem, but those kinds of sharp light gradients tend to give me headaches - so mostly I either use dim lighting inside or go outside.)

Based on this video, the Fresnel lens and diffusion layers in modern TVs do a great job of pushing light outwards and softening the gradient

That is SO COOL, thanks for the link.

The guy in the video is using inaccurate vocabulary, there are no fresnel lenses in a flat panel LCD/TV. This page shows the typical layers you'll find in a modern display:

https://pid.samsungdisplay.com/en/learning-center/blog/lcd-structure

In the video when he shows a film, you can tell it is bending light not focusing it - so it is likely a fresnel prism sheet that he is holding (not a fresnel lens as he states).

You can use a fresnel lens to make a light source appear to be further away as he suggest, but that requires more depth as the light source needs to be at the focal point of the lens. The other problem is that you can only have 1 LED at the focal point for the whole sheet, so you won't get that much light coming out even if you use a high powered LED.

You are likely to get better results buying a $50 LED light panel on Amazon compared to trying to recycle parts from an old LCD (though perhaps not as much fun). LED sources for LCDs often have poor CRI so the light quality you'll get from this approach is likely to be bad in person. I suggest searching for 90+ CRI with CCT >6000K LED Light panels.

I wonder if the claim of extreme bright light alleviating the symptoms of SAD has been tested by more than one person. While efficacy is not correlated with popularity, given that this is a rational-thinking based forum, it would be at least nice to know if the device works.

Did you miss the part about how a bunch of different people were doing this and benefitted from it? Or are you just assuming that those people didn't officially have SAD?

I don't see that part anywhere, only the one example that everyone refers to.

What do you want?

Do you want to buy something for yourself, or do you want a company to change the world?

Yes, there is room for a better product, but I think that off-the-shelf products are pretty good and you should just get them. If you want to change the world, maybe you should just promote these existing products. In particular, for your short term needs, just do it.

I think that the right answer for most people and most purposes is Raemon's instructions, $300 for 300 watts, same total wattage as coelux. Why did you write this post already knowing about Raemon's instructions? What are they lacking? That they require installation? If you have 24 separate bulbs spread around the room, installation is unavoidable. Light strips may be a better solution, but they require even more installation.

Some people want different things. David Chapman seems to want to illuminate his desk, not his room, so he might not like Raemon's setup. If you want to minimize installation, you might want a single light. This leads to Ben and Ashen's suggestions. They probably aren't as nice as coelux, so, yes, it would be nice if someone made nicer versions (which should be possible). Ashen's outdoor floodlights probably have lousy CRI. Ben's corncob isn't the standard residential fixture, and thus required some assembly. Both products probably shine outwards to illuminate an area, rather than the coelux which is intended to mimic the sun through a window pushing light in a sharp line. This illusion is probably luxurious, but I'm skeptical that it is actually good for the goal.

I was going to follow up by saying that if you like the form factor of coelux, there are similar products on the market for maybe $2/watt, only twice as expensive as Raemon's setup. They aren't as bright as coelux, but you could get 5 or 10. There is the second product Ashen linked or light therapy boxes (apparently 72W) are probably a good option with full spectrum and good lenses. But then I read more I heard a lot of accusations of poor quality and fraud around light boxes, so I dunno.

The best solution I could find was LED security flood lights, e.g.

https://www.amazon.co.uk/CampHiking®-FloodLight-Landscape-Spotlight-Waterproof/dp/B07JMQXXMW/ref=sr_1_9?keywords=500w+led+flood+lights+security&qid=1574927272&s=lighting&sr=1-9

So this would be less than 100 dollars for approx 40000 lumen, with all in one enclosure including head sink, can be wired to mains or wall socket. Also with this design they can be angled.

Not adjustable in brightness or colour temperature, but my preference would be overhead lighting for day, and then incandescent side lamps after dark (a sun above vs. fire).

In terms of consumer product, I think something like this might be ideal:

https://www.amazon.co.uk/Ceiling-Dimming-Bathroom-Corridor-6M5252TYQ/dp/B07MCTVH5V/ref=sr_1_fkmr0_2?keywords=lED+ceiling+lamp+office+lamp+with+remote+control%2C+28W+2800lm+3000k-6000K+dimmable+LED+circuit+board+ceiling+light%2C+splashproof%2C+round+bedroom+light%2C+for&qid=1574930392&sr=8-2-fkmr0

But more like 300W instead of 28W. So taking the enclosure and remote control of the bathroom type light, with the LED setup of a floodlight. As for CRI, I guess it would be bad. How important is CRI though? Does this relate to subjective sense of "harshness"?

I also found this: https://nofilmschool.com/diy-light-panel-busted-lcd-tv

Stresses importance of size, diffusion pads and fresnel lens for creating a soft, diffuse light.

Was thinking a good DIY project would be to take a LED floodlight and wire in behind a busted 50" display as a side panel (artificial window).

So the ideal consumer product might need to have a pretty wide surface area and fresnel lens which would drive up costs.

Also saw this on hacker news today: https://news.ycombinator.com/item?id=21660718

one comment "Lighting is a really hard business (especially residential)"

Note for people building a nuanced model of the moderation policy: 

I've frontpaged this. This was a bit of an edge case for the frontpage guidelines since it's a call to action, and we don't normally frontpage "startup announcements," which is a similar genre to this, at least superficially. But, the difference seemed important: this post's primary goal seems more like aggregating information rather than directly bidding for attention.

Detoolbox has a bunch of market validation checklists.

I have been looking into doing this. Pm me if you want to do it together. I'm from Toronto but am willing to work with people from elsewhere.

(Especially if you have any product design experience, or think you can figure it out)

I don’t have a robust way of estimating ambient light

Did you consider buying a lux meter?

I've ordered one of these, so I hope I'm not missing something.

If someone does this - I think for this particular product, the obvious way to get validation is kickstarter or Indiegogo. It's what could be a good looking tech product, with a group of people with very high demand, and a great story, but also high fixed costs.

Pretty perfect for the Kickstarter model.

I'm curious to what extents the benefits of this depend on race. I would expect the optimal lighting for an African who's ancestors were exposed to far more solar radiation to be higher than for a European who's ancestors were exposed to far less.

Huh that company you link to at the end also has this section: https://store.yujiintl.com/collections/high-cri-led-emitters

Maybe this is just a matter of buying this emitter https://store.yujiintl.com/collections/high-cri-led-emitters/products/bc-series-high-cri-high-power-cob-led-5600k-bc270h-unit-1pcs?variant=25100635143 and hooking up to a sufficiently quiet highsink + packaging it in a more usable form factor.

I wonder if there would be issues about heat dissipation / potential fires though?

I've done a bit of research on this. I think something along these lines is practical. My biggest uncertainty is what a "usable form factor" is (in particular I don't know how much diffusion you'd need, or in what shape, with a very small emitter like this).

FWIW, the Yuji chips are insanely expensive per lumen and seem to be on the low end of efficiency (actually they seem like such a bad deal that I'm worried I'm missing something). The chip that came out on top in my spreadsheet was this Bridgelux chip which is about 1/10 as expensive per lumen and 2x as efficient (but has a larger light-emitting surface and a CRI of 90 instead of 95).

With a low-profile, silent fan and efficient (120+ lm/W) emitters, you shouldn't need that much of a heat sink to keep the fixtures below, say, 60° C.

Disclaimer: I haven't actually finished building my DIY lamp attempt, so this could all turn out to be wrong :)