You can do-it-yourself https://youtu.be/6bqBsHSwPgw?si=fWO5-pYa6kPYKLZO

Thanks. I'll watch that. It doesn't seem to have images but maybe you could have the scenery window separately and just look at one thing at a time :P

I've considered setting up mirrors in my garden to redirect sunlight into a shaded room but never quite got it off the ground.

There's also a commercial version:

https://www.coelux.com/

You can also buy this from Alibaba - just the real thing, not the LCD flat panels. (the real ones are 10-20cm deep). I got a few two winters ago, and they are amazing for dark and gloomy Polish winters.

https://www.alibaba.com/product-detail/Circle-Artificial-Sun...

That's awesome, but the most powerful one is 9000 lumens from a 1200x600 mm panel, which is 10000 lumen/m^2. I don't think that's good enough for a proper sun effect since sunlight is 100000 lumens/m^2 and even outdoors in the shade is brighter than these devices. But it's certainly a step in the right direction and no doubt much better than natural light for you.

There is an Italian company called Coelux which builds something like this:

https://www.youtube.com/watch?v=aJ4TJ4-kkDw

That’s pretty neat, thanks for linking to Coelux’s video.

Apparently the video was recorded in 2014 so they’ve been around for at least 10years now.

One step away from a real human factory farm

You know, I co-founded a smart LED lighting company well over a decade ago and we considered this market.

It seems like the potential applications might make this viable now. Cruise ships are a tiny market when compared to all the dead commercial office space in downtown cores that people wish to convert to residential but can’t because of lack of sunlight and similar reasons.

That's cool. How did/would the technology have worked?

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 https://youtu.be/6bqBsHSwPgw?si=fWO5-pYa6kPYKLZO