Artificial Sunlight (official topic)

Been following this designer for a while, realeased a really interesting product that looks pretty good. He did a version contained in a box, but didn't make the funding, nice idea to bounce a lamp off the mirror. Would be great with a cct adjustable spot light to move through the day. https://artmospherelights.com/products/lighting-system-for-natural-light

Well hello everyone! I realize this is an old project but I've been working on a version of this at home. I haven't yet hooked up the cooling system, but the water block itself keeps it cool enough for short bursts while I was testing things. I have a 500 watt LED mounted on a 40inch mirrored dish, PC cooling system mounted in a custom frame, and all that mounted to a tripod. For the window, I have two pieces of clear acrylic and multiple sheets of Waterproof Inkjet Film sandwiched between the acrylic from an industrial role I purchased. I was only able to test shining the light through my "window" once so far, but in that one test it worked really well. The only issue was I could see the dish still through the "blue sky" in the window. I need to test putting some more sheets in, vs the placement (distance) of the light behind the window to try and keep that from happening. Anyways... just posting to show we're still playing around with this concept!

WOW. That looks like you're getting ready to light up the dark side of the moon. That's great work.

I am looking for a way to simulate a skylight or window in a bathroom with no exterior wall. Came across OP's incredible YouTube video and DIY project. I'm looking for an out-of-the-box solution an electrician can install, and more affordable alternatives to the CoeLux products. Hope it's OK to ask in this thread.

In addition to the Yuji Lighting Skyline products mentioned in this thread, I found the following (these aren't referral links):

• Pesetech Artificial Skylight
• Yeelight Pro P20 Rooflight
• Rongyang OPT (RYOPT) Skylight

Anyone have experience or opinions about these products?

Also found these relevant customer videos:

• Pesetech unboxing, testing, post-install videos
• Yeelight unboxing and post-install videos

Saw an Amazon review that said about the Pesetech:

This product is not CSA and no licensed electrician will install this for me.

@lazytinkerer I'm your guy for this. Gone round and round on this for a dark office, and think the best, most cost effective way to simulate daylight isn't to go down the blue sky/ sun route, and instead simulate overcast high quality nice bright light.

Ended up copying this https://www.innerscene.com/products/circadian-sky?gad_source=1&gclid=Cj0KCQjwjLGyBhCYARIsAPqTz1-3fFaLo0aR0lVWDXRm08k5bVVPS1oxWm7J6RtfTxbpe4uF_OyrxwQaAipbEALw_wcB  

and this https://www.google.com/search?q=lightglass&rlz=1C5CHFA_enGB1105GB1105&oq=lightg&gs_lcrp=EgZjaHJvbWUqDggAEEUYJxg7GIAEGIoFMg4IABBFGCcYOxiABBiKBTIGCAEQRRg5Mg0IAhAuGK8BGMcBGIAEMg0IAxAAGIMBGLEDGIAEMgcIBBAAGIAEMg0IBRAuGK8BGMcBGIAEMgcIBhAAGIAEMgkIBxAAGAoYgAQyBwgIEAAYgAQyBwgJEAAYgASoAgCwAgA&sourceid=chrome&ie=UTF-8

Found a realllly high cri led panel from here https://ledstore.pro/. cct changeable so can change to what I need. Got some windows coming soon, will bed the panel behind the window, and have the light high up in the wall, simulating a clestory. Should be brighter and more natural than the artificial skylights, which I reckon are super dissapointing.

@bigfield Thanks for the suggestion. The overcast sky simulation rather than blue sky does make sense.

Why did you not go with the Circadian Sky and Lightglass products? Is it because those are not for consumers and unaffordable?

Is the CCT panel you chose one of these? https://ledstore.pro/ledstore/cct-led-lights/cct-led-panels

I was able to finish my copy cat build from the video. During that process I got some of my own ideas for a reliable & "production ready" version that I can use in my house. The blue light scattering you get from those printer sheets is fantastic. That coupled with a DMX show controller synced up to my LED, with a wall unit that allows me to select between pre-programmed weather (noon, overcast, evening, morning, or automatic) and I have all the elements to properly install this in my attic as an artificial skylight. It's impossible to get a good picture... but im very happy with the results. Ill post pictures when I get the skylight installed.

@lazytinkerer Not looked into the circardian sky products price, but the shipping from USA to UK for the Lightglass was very expensive, and the cost of the product itself was pretty expensive considering you can get a higher cri panel from that website for £200-£300, and it is just an led panel + glass . And yep that's the one, got the 300x1200mm. I don't have a false ceiling, so thought burying this in a wall would work better. Will report back when installed with the glass properly.

@remitchou what wattage LEDs are you using and how are you cooling them or what are they mounted on?  I can't do cnc metal frames, so looking for something that's not dangerous with plywood or that I could do with thin aluminum bars screwed together.

You have the best blue sky background, -- is it the inside of the boxes you painted, and what shade of blue did you use?

This is fantastic by the way.  

@remitchou that looks great. Where did you get the film from? I bought some but I must have bought the wrong type.

@Pyrrhos
@Jordiemc

I put 2 layers of inkjet film, to increase the tyndall effect. If I put 3 layers, the light will become too yellow (even with a 6500K LED). As I wanted daylight, I left 2 layers of film, and I painted the inside in blue which slightly reinforces the blue sky effect. Black paint works well too but sky blue paint was the best .

A plywood box should work well. You will need to be careful to manufacture it on a perfect plane and ideally cut it by a CNC. If the fresnel plane and led plane are not perfectly // the rays will not be parallel too. The LED and the fresnel lens must also be perfectly placed in the middle of the box.

Material:

1414 cob led, 10w, cri 95 , 6500K

Driver

https://fr.aliexpress.com/item/4001135767294.html?spm=a2g0o.order_list.order_list_main.45.39ef5e5bgQ450m&gatewayAdapt=glo2fra

inkjet film roll

https://fr.aliexpress.com/item/32807226254.html?spm=a2g0o.order_list.order_list_main.49.39ef5e5bgQ450m&gatewayAdapt=glo2fra

Heatsink Radiator

https://www.aliexpress.com/item/1005001787363772.html?spm=a2g0o.order_list.order_list_main.24.39ef5e5bgQ450m

fresnel Lens

https://www.aliexpress.com/item/33013578596.html?spm=a2g0o.order_list.order_list_main.39.39ef5e5bgQ450m

@remitchou very impressive results you are getting! Any possibility you would post design details, links to materials etc?

Hello, a long time lurker on this project. Always wanted to make it, but I am not a DIY person, nor could I find a used Satellite dish, for sale or for free. Thanks for everyone on this project, I now know Rayleigh scattering can be done with just waterproofed inkjet film pretty convincingly. As for the parabolic reflector, I recently found this 1.35m parabolic cooker for sale on TaoBao for ~ 30 bucks (+$10-15 for shipping its HEAVY)

It looks to be exactly what DIYperks made in the video, but prebuilt. Do you guys think this will work? 

Another thing I need help understanding is, in the original video, the 500w led is mounted quite a bit off centre

 From my understanding, it should be somewhere down here right? 

@cheliodas Just be careful with Chinese stuff. Some can be very good, but the Chinese do copy things very well so they LOOK good but the materials are often very poor so they are little better than stiff paper. Caveat emptor really applies here more than in most places.

Depends where you are in the world, but dishes are still widely sold in Europe for television use.

@Cheliodas

There are different setups of parabolas

In your first photos, it is an axial parabola. The most commonly used mounting is off-axis

@marcdraco  I live in Hong Kong so most people don’t own homes (usually flats) and that I presume translate to less satellite dish being sold because nobody owns them in the first place (besides big companies). Thanks for the precaution on Chinese products but, I frequently buy from them and usually they are as good as it needs to serve its purpose (but not premium unless you pay premium), but I guess I can only tell after I buy it. Theoretically, if it can focus sunlight into a single point for cooking, it should work vice versa right?

@remitchou I see, thanks for the explanation. I guess putting my light at the centre should still be okay if i put the whole set up high enough..

@cheliodas I buy a lot of Chinese stuff myself (I have to import it of course) and some of it is very high quality indeed. The caveat (as you've noted) is primarily because you can't "try it" before you spend money.

Some Chinese electrical gear is so dangerous it should not be sold, but it's even available in Europe with CE marks!

If it works for YOU that's all that matters really. (Worst case you could probably cover it in fibreglass as a stiffener.)

@remitchou - great explanation too.

Latest prototype installed in the office.  Our interns have a big interior windowless room where they work.  The ceiling panels are 24 inches square.  This is 300mm square panels (300mm focal length), with 18w LEDs.  They're advertised as 10,000K bluish white and 90cri.  One layer of waterproof inkjet sheet.  

The pattern on the wall is I think from the adjacent LEDs, my next version (hit tip @remitchou) will have baffling painted blue which should eliminate the artifacts and give more sky blue color.  I'm going to try to slim it down, have 150x250mm fresnels with 150mm focal length on the way, and 40w LEDs.  Should be much brighter and look cleaner.

@pyrrhos you should be able to reduce the artifacts by flipping the fresnel lenses over.

That said, I'm curious as to why you chose to angle them. It's not a bad look, but angling the light source should have been enough to get a sideways light effect.

@fhr Actually you can't see it from that angle but the LEDs are mounted perpendicular to the lenses.  I angled the lenses because 1) overhead sunlight is a drastic high contrast look, lots of shadow, etc. and not natural for use (we're nowhere near the equator and 2) it let me fit larger lenses into the 24 in x 24 in square.  Unfortunately I can't flip the lenses either because they're collimating the led light source, and that only works one way.

Here's a better shot of what's in the ceiling.

@pyrrhos the angle of the lense will have limited effect on the beam direction. The image of the led will always be projected in a straight line going through the lense center.  But in your case you were probably right, if it simplifies setup.

To limit the amount of artifacts, adding matte white walls between the cells will help. They'll diffuse the light somewhat and will avoid having "multiple suns"

Hey all, I'm new here and really inspired by the discoveries that have been made in this thread.

I'm in the process of building my own lamp, for the purpose of film production. Instead of combining a cob LED with a heatsink or watercooling I'm going to install a Zhiyun Molus X100 in the lamp. It's a small, bicolor 100W LED with high CRI. Batterypowered and controllable via bluetooth. 

I have an idea I want to test, which I would love to hear your thoughts on: To install an LCD display in front of the lamp, with the backlight element removed, and then to play a video on it to cast shadows. A bit like how a normal LCD projector functions. I would want to cast the kind of rustling shadows that occur when the sun shines through the leaves of a tree. Do you think a normal LCD would be able to at least partially block out the light coming from behind, or would the light just blast through it?

Also, @shavings I'd love to buy some of that waterproof inkjet sheet from you, if you still have a stash 🙂 Apparently I'm too new on the forum to be allowed to send private messages.

I made a prototype for the Coelux 45 HC. I saw this light in person in London and wanted to buy it for my family’s shop, and maybe put it in my house one day. However, the price was a bit higher than I expected.

Anyway, thanks to everyone here; I read every word everyone posted. I planned this prototype a year ago in the simulation, but was only able to complete it after someone mentioned using inkjet paper (thank you 🙏🏼). I almost followed Matt’s method using soap water. Now, using the prototype, I have the confidence to buy a proper light source and install it in the shop.

@zero that looks very interesting! What are you using to collimate the light? I'd be interesting in seeing a picture/sketch of the internals.

@holdit thank you! 
here is the schematic https://forum.diyperks.com/postid/4262/  

You need to set the mirrors to be the same size as the incoming light ray.

I use two basic mirrors. For a long time, I searched for a first surface mirror, as I thought a normal mirror would lose some light due to imperfect reflectivity. However, I saw that Coelux is just using normal mirrors, or at least that's what I think based on their installation guide.

@zero thank you and thanks for the additional info also. I'm looking forward to seeing how your build develops

@diyperks winter is coming... any chance we'll get V2 released in time to save us from the darkness?

I'm beginning this project today -- I have an old satellite dish that I'm repurposing for this, and the reflective vynil adhesive should be arriving within the next couple days. I figure I'll get the light sorted out and then worry about the window / blue light scattering thing later. Once it's built, I'll cut a hole in my livingroom ceiling and have it shine down from my attic onto my living room couch 🙂 I already have speaker wires and ethernet going up from my shelf, throwing a power cable up there too shouldn't be too much of an issue:

My materials so far are:

• This LED: https://www.aliexpress.us/item/3256802501151936.html
• This power source: https://www.aliexpress.us/item/2251832788842825.html
• This heatsink and lens: https://www.aliexpress.us/item/3256802401671224.html

On the lens, I figure limiting the angle to ~90 degrees means more of the light will actually hit the dish rather than just light up my attic.

My main worries / concerns are:

1. Wiring: I can route a power cable up to the attic to power the power supply, but i guess I will need more power to power the heatsink fan. I'm not sure how best to do that -- ideally i would like one power cable that I need to send through my ceiling.
2. The power source: I picked a very variable power source since it would most reasonably allow me to swap out the LED for a more powerful one in the future. But it's not really an LED driver exactly. I'm not familiar enough with the pros and cons to determine whether this will be a problem to worry about or not

I'll keep you posted with my progress! If anyone has ideas regarding my worries, I'd love any input.

I'll just dive in here and welcome you to our forums. The power cable interests me most but I'm not involved in this design so I don't know how much current we're throwing around here. The point about power, is that it's easier to chuck high voltage than it is current. Long story short, it would likely be better to move the LED's PSU as close to the LED as possible (within reason).

I'm not aware of any special considerations (except power) for these large LED arrays, but I could be wrong about that so I'm not going to guess.