What is the best solution for circadian-friendly artificial light?

Link is broken for me

https://www.creelighting.com/products/indoor/dynamic-lighting-experience/cadiant

Thank you! I’ll be checking it.

Edit: I saw that once, but didn’t know where they sold it. It must be expensive as… And requires installation. Apart from that, it may be good (although it doesn’t reach very low color temperatures).

You might look into this company. These lights have been around for decades. I have one I use for reading and checking print color. Works well. No eye strain. 96 CRI thereabouts. In order to maintain high color accuracy it’s best to change out the bulb(s) every couple years. Litho houses use these for judging press color. School classrooms claim 30% increase with student productivity. There’s data out there but I’m too lazy to go find it again.

Ott Lights

thank you for adding to my education about LED options

I looked at their bulbs, here is one at 5000k for $16 plus shipping, but I cant find the CRI specs
https://products.ottlite.com/p-480-85w-edison-base-led-bulb-60w-equivalent.aspx

and they dont offer Warm White

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for $18 w free shipping, Im glad I ordered one of these 95 CRI warm white to test:

At this point, I don’t think there is an automatic or semiautomatic solution that is good enough for the criteria that I stated in the OP. There are many companies out there and there might be options, but these specifications aren’t mainstream, so they may be only accessible for the wealthy.

So I will go with the strategy of just buying a good daytime bulb (5000-5500K, smooth spectrum, not lacking red wavelengths, zero flicker), and a good nighttime bulb to use after sunset (whose spectrum’s output is >560-580 nm, and zero flicker).

For the daytime, I will go for SunLike bulbs, as I couldn’t find anything better. They’re expensive, but I think they’re worth it and will last many years.

I’m still deciding whether to get 5000K or 5500K:

- The argument is that 5500K is better to entrain circadian rhythms during the day,

- But if you work close to a screen, which works by an RGB system, it will be emitting a blue peak without turquoise at about 450 nm.

- That means that if you use an ambient light of 5500K plus your screen close to you, then the actual spectrum your eyes are perceiving is too blueish.

- So it may be better, health-wise, to get 5000K bulbs, as everyone works around screens nowadays and that will “balance out” the spectrum that your eyes receive. I’ve seen that SunLikeLamps also sells two combinations of 5000K and 5600K CTL in a proportion of 60:40 or 60:40 that result in 5200K and 5300K, respectively. Those would work too. Personally, I’ll be deciding whether 5000K or 5200K.

- Now, regarding the model, light intensity is crucial to entrain circadian rhythms during the daytime. The perfect spectrum won’t matter if you only get a few lux with it. So I’ll choose a at least 15W bulb and will use 2 bulbs as ambient light in the ceiling lamp, plus 1 bulb in a desk lamp close to me (but as indirect light, with the bulb never in my field of vision). Of course, most of the time I seek sunlight and work close to a windows—nothing will ever beat natural light.

I’ll write tomorrow in regard to a good orange or red bulb for nighttime, but it’s not being easier to find.

I use the Fireflies NOV-MU with E21A 2000K every night. It is ultra high cri and emits the lowest blue wavelength I’ve ever measured. I also use the Clemence modded Skilhunt H04RC. Both are usb rechargeable and I leave them plugged in when running them at night.

Pero nada sera perfecto

You might try something like this Indoor growlight with remote

You can have a little plant buddy to live inside too if you want. You can just set the (only) red light to be on for 3 (or 6) hours a day for your sunset. Maybe turn on 1 hour before your other lights turn off.

There are lots of versions of these in many shapes and form factors. For ease, this is a screw in bulb.

I haven’t used this one, but I imagine it will last longer just using red at maybe 14-22 watts of power.

Edit: The linked light has clones sold under different names. They have a typo. It has 28 red (620/660nm), 18 blue, 18 warm white (~1.8-2K) diodes.

This meets your requirements (& of NIH study) if you want no blue or green at sunset.

I use a D4V2 with the 200k e21a emitters as my nightstand light. Does the job very well, great for candle mode.

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You are welcome of course.

The light I got was ten years ago and the Ott Co. offered CRI rating at the time. Current company bought him out and right, I don’t see CRI on their pages. Probably because everything they make seeks to be like daylight. An impossible task but everyone tries. Oddly, or interestingly, the quilting world uses Ottlites for judging fabric color. I use one to check color balance on photo prints, and it’s the best I’ve found so far. The waveform bulb you ordered looks good. Think I’ll try one. Thanks for the idea. I’ve had trouble with specialty bulbs holding up, but maybe this one will. The LED bulb companies claim theirs will last five years or ten years, but they never do (for me) and I rarely save receipts that long, and they know it.

just received the
Waveform 3000k LED bulb

first impressions… seems nice, glad to have it as an option

I removed an incandescent that is rated at 29 watts, on my meter it makes 8 lumens, and gets too hot to touch

I installed the waveform light rated at 10 watts, it makes 70 lumens on my meter and it is not hot to touch

so, the LED bulb uses 1/3 the power, and makes 9x the lumens… and so far the color rendering seems good, and the tint does not seem green… I think I like it…

You can buy them from China directly now. No blue spike and appears to use the same “sunlike” chip. Almost identical to incandescent. I wish they come in retrofit or BR30 format though…

https://item.taobao.com/item.htm?id=585513116587

thanks for the link… I cant make any sense of it though

Neither can most. Taobao is basically a chinese only webstore.

Just use Chrome’s translate. You can order with their built in forwarder. Search the web, there are tutorials. Or use an agent.

Good idea!

I've been avoiding Taobao because it's not in English, but I think I'll just using Chrome's translate.

I hear that things are usually cheaper on Taobao than on AliExpress.

[quote=raccoon city]

[quote=aherklp]

It depends, for small light stuff AliExpress is cheaper. If you buy heavier stuff, or aggregate multiple order, and forward it once, then Taobao.

Btw, this is the newest version with an even better spectrum, notice the efficiency loss as a result. (You can kind of estimate the spectrum just by looking at the lumen efficiency)
https://item.taobao.com/item.htm?id=654264933998

Forgot to mention, for night light I went back to halogen/incandescent light since they are literally perfect lights…

In addition to the blue light much dangerous for night sleep It’s looking direct the Led die.
This happens when there isn’t adequate diffusion such as a piece of white plastic.
Like the Led Corn bulbs,the orrible greenish street lamps or the ice cold car lights pointed on face.
Another important rule, avoid watch phone or others white display light in evening
The conventional PC Leds with the same amount blue light of incandescent are <2000k
However I liked dimming incandescent on my bedroom,easy and cheap.

Hi,

About a month ago I tried to order the bulbs at sunlikelamp.com, but he does not accept PayPal anymore. I wonder if I could get bulbs made with sunlike LEDs via other sellers, does anyone know?

If you want the exact same chip, you can buy it from https://item.taobao.com/item.htm?id=585513116587

But an improved spectrum is now available at 商品详情