Building a realistic artificial sun (for dark winter days)

DIY Perks9 HN recommenders · 2020–2025
3.3M views · demo · evergreen · Uploaded 2020-10-31

DIY Perks builds a realistic artificial sun for dark winters, using a powerful water-cooled LED, a satellite dish reflector for near-parallel rays, and a scattering layer to mimic the blue sky. The video explains the optics behind why most lamps do not look like sunlight and shows the build and its results.

Whenever HN discusses seasonal affective disorder, myopia, or bright home lighting, people point to this as the most convincing buildable example of sunlight-like illumination.

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20 comments from Hacker News

@wooptoo2020 · in “Watercooling a Canon R5 to enable unlimited 8K recording”

This is the same chap who built Archimede's death ray in his bedroom. That video was even more impressive. [VIDEO]

@LadyCailin2021 · in “Myopia treatment 'smart glasses' from Japan to be sold in Asia”

You might be interested in this video too. There’s more to it than just the color, sunlight’s rays are (virtually) parallel, because the light source is so far away. [VIDEO]

@142022 · in “Someone should probably start a bright home lighting company (2019)”

I was going to suggest diy perks but thought you were going to link his artificial sun video [1]. I’ve been wanting to build one but not sure where I could fit since it requires a bit more space then a bright led build would. [VIDEO]

@UnpossibleJim2022 · in “Someone should probably start a bright home lighting company (2019)”

This isn't quite what you're looking for, but this has some of what you're looking for, which is how to get the "parallel light effect" that the sun has, so it doesn't look like a bulb, and diffuses properly: [VIDEO] Hope this helps a little.

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@sbt5672022 · in “Quicker and easier ways to get more light”

Definitely not quicker and easier, but artificial sunlight (like this [VIDEO] ) has impressed me and wondering if there are ready made solution for that

@implements2022 · in “Quicker and easier ways to get more light”

Relevant YouTube video with 2M views: “Building an artificial sun that looks unbelievably realistic …” [VIDEO] [LINK] Uses a water cooled LED lamp reflected off a satellite dish to produce parallelised rays and through a soapy filter to provide diffuse light. Bulky, but literally lights a room as if from a morning sun on a spring day.

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@hackererror4042022 · in “Shortsightedness has become an epidemic”

There's an amazing youtuber/creator I've been following for a while and he does exactly this. Goes into the science of what it takes, and the results are really stunning. I'd love to give something like this a try, just need time. [VIDEO] Also there was a breakthrough a while ago with LED ceiling lights that mimic natural sun. I haven't heard much since their release, so I'm sure cost is still a major issue for these sadly. [LINK]

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@deltasevennine2022 · in “Ask HN: Why are there so few artificial sunlight or artificial window products?”

[VIDEO] If you want one, you can build one following the video above. The result is quite stunning. I've never seen anything like it. [LINK] The one above is an easier build that takes up less space.

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@laserlight2022 · in “Ask HN: Why are there so few artificial sunlight or artificial window products?”

> satellite dish, silvered, with an LED array at the focal point An example from DIY Perks YouTube channel [0]. [0] Building an artificial sun that looks unbelievably realistic. [VIDEO]

@mongol2022 · in “Ask HN: How do you navigate Seasonal Affective Disorder?”

Reminds me about the DIY Perks "Artificial sun". Is something like that for sale as a product? I think it definitely can help. [VIDEO]

@mxstbr2022 · in “Circadian lighting with Home Assistant: Like f.lux, but for your house”

This reminded me of the video by DIY Perks building an "artificial sunlight" for their office: [VIDEO] The amount of effort is unbelievable, but I'd love to have something like this at home. I can only imagine the impact on my productivity during winter evenings…

@rektide2022 · in “High CRI LED Lighting”

I really wish more led lighting was high CRI. We've suffered a huge degredation to our world vua this switch to efficiency & it's sad & unknown. Boo. These Yuji led folk notably appear in the DIY Perks videos on indoor sunlight! He uses a 500W watercooled setup & adapted parabolic satellite dish reflector in the second to make good parallel-rays sunlight. [LINK] [VIDEO]

@snozolli2023 · in “DIY triple-screen laptop based on the framework”

This guy also showed how to make an "artificial sun" that's proven very helpful to me in Oregon winters: [VIDEO]

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@goda902023 · in “Lack of sunlight during the day is worse than electric lighting at night”

I don't have SAD(at least to a degree I notice), but I do occasionally daydream of having something like this artificial sunlight in my windowless office at work. If only I had more space. [VIDEO]

@alright25652024 · in “A myopia epidemic is sweeping the globe”

This is a rabbit hole :) In short, no, unless you have tens-of-thousands[1][2] to spend on this panel. Rays of sunlight are parallel, an effect that very difficult to emulate. There are folks who have developed DIY versions, with impressive results[3], but in that case you're trading off way more effort, potentially requiring maintenance, and a lot more space required. [1]: [LINK] [2]: [LINK] [3]: [VIDEO]

@lowkey2024 · in “Cruise ships chopped in half are a license to print money”

There are some other implemenations listed on this page. The trick is to make sure the light rays are parallel as if coming from an infinite distance like the sun. To create the blue sky effect the easiest way is to pass the light through soapy water like in this video posted above [VIDEO]

@bmelton2025 · in “How to improve your WFH lighting to reduce eye strain”

I'd wager they're pretty good. If you can leverage a parabolic reflector at a light's focal length, you can get them to collimate in a way that approximates the sun by appearing to be pinned near-infinitely far away. The reflector is generally what takes up the space, but it's necessary(ish) -- you could approximate the effect by using a fresnel lens at the light's focal length, but it yields a smaller light with rainbowing effects. [This video]( [VIDEO] ) does a good job of showing how to make your own, as well as illustrating how good the effect is, while also demonstrating why space-hog implementations are likely to yield good results and slimmer ones not.

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@stephenpontes2025 · in “I tried making artificial sunlight at home”

DIY Perks also attempted to make artificial sunlight at home, also focusing on things like Rayleigh scattering! This was a great watch: [VIDEO] EDIT: After reading the article, I see the OP calls out DIY Perks specifically - the OPs design is much more compact :) > It's compact. The total size is 19cm x 19cm x 9cm. This is quite compact for a 5cm focal length and an effective lighting area of 18cm x 18cm. Reflective designs like the DIYPerks video or commercial products like CoeLux do not achieve this form factor.

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@Wistar2025 · in “I tried making artificial sunlight at home”

I cannot remember if I first saw this here on HN but, here is a detailed video of an incredible artificial sunlight rig build. It's big but the results look, well, amazingly real, at least to the camera. [VIDEO]

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@jaggederest2025 · in “How to maintain good vision amidst the myopia epidemic”

Think operating room or photo studio. 100w grow light panel for every 2-3 square meters - so for a typical office, 4 100w lights, with a scatter panel in front. I really like this video for an example of how to make proper scattering effect, but you can buy similar materials that are more durable and lighter, for in e.g. a drop ceiling: [VIDEO]

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