[upofadown]

Your visual system has to adapt all the way from the bluish light of midday to the reddish light at the end of the day. You can adapt to whatever light is available to you and after an initial adaptation period you can't tell the difference. There is no need for trickery as the system tricks itself.

To replace sunlight you can use any bright light with enough blue light in it to stimulate the circadian system. You can even use straight blue light if you want.

Most ridiculous phrase:

> ... it also produces the texture and feel of sunlight.

[Broken_Hippo]

Sir, would you rather sit by this nice, blue light or here in this stuff that feels warm like sunlight?

Sure, you can do that with the blue light, but if that were truly an answer, the blue lights would be standard in fixtures instead of a bit of equpiment for greenhouses, fishkeepers, and those with seasonal affective disorder.

Sunlight simply feels different, in the same ways that a fake fire can feel different from a real one. It is warm and inviting for most people, it heats the skin in ways normal light doesn't.

And as far as texture, I'm not sure if I can explain this properly, though I can see it and draw it in: Sunlight makes the skin's transluscence light up a bit differently: Sometimes it wavers and moves depending on what is in the air and whether or not there is a temperature difference between the inside and outside. Sometimes dust sparkles slightly as it drifts in the air. It creates a different glow than artificial light and the shadows are different - the light is steady and more diffuse because the light comes from a general direction instead of a point.

I do understand that some of this stuff are things that people just don't think they see but they are the things that help make a painting spectacular instead of just good.

[sonium]

I think you might oversimplify matters a bit. If the pictures are original, I think this is quite remarkable.

Let me state three properties about daylight which I think this light source addresses very well:

1) Directionality: Sunlight produces a almost parallel bundle of light, unlike most domestic light sources which produce divergent light bundles. This is because sunlight comes from a indefinitely (for that scale) far away light source. If you want to emulate this you need some kind of optics. This is also different from an extended light source, e.g. a fluorescent tube / OLED which will not produce the sharp shadow edges as seen on this light source.

2) Color: The sky is blue, however sunlight is white (unless in morning or evening, where we see some atmosphere influence). The light source seems to be able to imitate this: It looks blue, but it produces perfectly white looking light (as one can see on the surfaces that it illuminates)

3) 'Texture and feel': You can feel direct sunlight because it is warm. This is because it has a lot of energy, around 1kW/m^2. This is a lot more than what domestic light sources usually produce. Typical light sources put out up to 500 lux, while direct sunlight is more than 30000 lux.

All together it seems quite remarkable, and I would really like to know how this all works.