How to Replicate Full Spectrum Sunlight Indoors: The Ultimate Light Bulb Test! (with data)

[itchaboyagain]

Finally! This has been several months in the making, and I'm so excited to share it with all of you.

As you’re probably aware, most light sources don’t come very close to mimicking the Sun’s full spectrum of light:

The typical LED spectrum has a large blue spike with a dip in the turquoise region, also very little red.

Light, especially bright full spectrum light, is necessary for all kinds of things, not least of which is our circadian dependent processes like sleep, hormone secretions, and mood.

Since many of us spend most of our time inside in our home or work offices, I wanted to know how close we could get to mimicking natural light indoors?

I ended up testing around 70 or so lights in this endeavor. And since I’ve run out of lights to test, I can now happily share with you the data from those tests as well as my thoughts, findings, and advice on how to go about using this information.

I should say the color spectrum data could have been better collected. For example, I didn't use a reflector dome and I didn't wait for the light to heat up before taking readings. But the point was simply to verify the rough spectrum read-outs, so I'm not that concerned with things like accurate duv.

Here's the data for your viewing pleasure:

Google Sheets: Light Bulb Test Data

Inside you’ll find some parameters you might not be familiar with, so here’s what I tested for:

• CRI: This is the Color Rendering Index and compares how well an artificial light source reflects light from 15 color samples when compared with a natural light source. ”Ra” is the total score and the highest this goes is 100, which would be identical to sunlight.
• TM-30: This is basically a newer version of the CRI standard and uses 99 color samples (this time from actual real world objects) to calculate a “Fidelity” score with a max of 100, similar to CRI. However, it also gives a “Gamut” score with 100 being identical to the saturation of sunlight, the gamut score can go over or under 100 for this reason.
• Flicker Percentage: This is the most popular way of measuring flicker from a light source. I’ve included scores with dimmers without dimmer and while dimmed. There we're a few bulbs I missed this on as I returned the device I was using for testing purposes.
• Flicker Videos: I've taken slow motion videos of all the lights I tested
• RF Interference: Very few lights produce RF interference, however since I’m normally quite mindful of man-made EMF I wanted to find a light source that isn’t producing tons of RF for no reason other than sloppy engineering.

I’ve also written a guide on this as well if you’d like to check that out. It contains all the links for the best lights, as well as ideas for implementing light setups of your own.

How to Replicate Full Spectrum Sunlight Indoors

Here are some of my thoughts on the lights I tested:

• The Shanpu Z0850/55Pro and the GE Sun Filled bulbs are the best on the market right now. Here’s a comparison of these lights compared with the spectrum of natural sunlight:

• As you can see, the Shanpu Z085o/55Pro is a spectacularly realistic LED. However, it's kind of a pain to buy as 3rd party TaoBao agents aren't super user-friendly. They're also fairly expensive and the lumens per watt is lower than most other LEDs, so you need more of them to achieve a better lux level, which of course jsut raises the cost more.
• All in, you're looking at like $600 to put out 10,000 lux from these. However, this is very high quality light, with no noticeable flicker. If you like paying for the good things in life, this is it!
• The cheaper and more accessible alternative is the GE Sun Filled lights. At $8-10 a pop, higher luminous output and available on Amazon, they're a great option for someone looking to fill their home with more realistic light. A potential downside is that they do have invisible flicker a bit in the 120Hz range, which could potentially cause sensitive people issues. I personally use these lights and haven't noticed any negative effects, but that doesn't mean they aren't there.
• NorbSmile also uses the SunLike diodes in their bulbs, but their offerings cost more than GE and flicker more as well, so I don't really see any reason to purchase their lights. I did email them about the clicker, and they said they'd be looking into it.
• I was initially very excited about the Sylvania Natural bulbs given the claims and price point, however, I encountered several issues. They’re outright lying about the SPD these give off. The 8w, 11w, and 13w 5000K A19 bulb all have a generic blue pump phosphor blend SPD, as you can see below. I’ve emailed Sylvania asking for an explanation, and have yet to hear a response.

• I also measured 16 of the 8w 5000K bulbs, and found each one had a flicker rate of 12%. None of the other Sylvania bulbs had flicker, as advertised, so this was unexpected. This shows a pretty severe lack of quality control in my opinion, seeing as how one of the big advertising features of these lights is the low flicker rate and dimming capabilities.
• I tested several of the leading contenders for the low-blue light bulb market. I think dim, low-blue lights in the evening are important. However, I’m not a fan of red and orange lighting, I find them very unnatural and uncomfortable personally.
• All the warm low wattage LEDs I tested had an insane amount of flicker, so these were a no-go.
• The Bedtime Bulb is an interesting product, however I think they’re too bright for nighttime use, even the lower wattage version, and the custom phosphor spectrum they accomplish isn’t really that special.
• In the end, the low wattage incandescent bulbs are the best evening light option in my opinion. The 7w bulbs for example don't exceed 10 lux even at a distance of 2 feet, which is perfect for evening use.

My Setup:

Alright, I'll end this with my current office setup.

1. I've built two large DIY chandeliers with six GE Sun Filled bulbs and one 53w halogen each. Though I think I'd like to make another... This gives the room most of its lux.
2. I also have a floor lamp with three halogen BR30s pointing towards me for more full spectrum infrared exposure, it gives off a pleasant warmth at around two feet.
3. And finally, I have a 48" UV reptile light mounted to the corner of my ceiling molding, spraying the room with a trace amount of UV light.

Here's what I've ended up with:

And here are the spectral graphs from this setup:

Here's the info from the UV light output for those interested:

1 ft: 3.5 UVI
2 ft: 1.5 UVI
3 ft: 0.8 UVI
4 ft: 0.5 UVI
5 ft: 0.2 UVI

Well, I think that's about it!

One more shameless plug to the guide I wrote up about all of this:

How to Replicate Full Spectrum Sunlight Indoors

Hopefully you found this information useful! Have a great week!

 

[LeeLemonoil]

Hopefully you found this information useful! Have a great week!

Very useful and valuable. Thanks a lot for sharing this work!!

 

[Inaut]

Finally! This has been several months in the making, and I'm so excited to share it with all of you.

As you’re probably aware, most light sources don’t come very close to mimicking the Sun’s full spectrum of light:

View attachment 37869
The typical LED spectrum has a large blue spike with a dip in the turquoise region, also very little red.

Light, especially bright full spectrum light, is necessary for all kinds of things, not least of which is our circadian dependent processes like sleep, hormone secretions, and mood.

Since many of us spend most of our time inside in our home or work offices, I wanted to know how close we could get to mimicking natural light indoors?

I ended up testing around 70 or so lights in this endeavor. And since I’ve run out of lights to test, I can now happily share with you the data from those tests as well as my thoughts, findings, and advice on how to go about using this information.

Here's the data for your viewing pleasure:

Google Sheets: Light Bulb Test Data

Inside you’ll find some parameters you might not be familiar with, so here’s what I tested for:

• CRI: This is the Color Rendering Index and compares how well an artificial light source reflects light from 15 color samples when compared with a natural light source. ”Ra” is the total score and the highest this goes is 100, which would be identical to sunlight.
• TM-30: This is basically a newer version of the CRI standard and uses 99 color samples (this time from actual real world objects) to calculate a “Fidelity” score with a max of 100, similar to CRI. However, it also gives a “Gamut” score with 100 being identical to the saturation of sunlight, the gamut score can go over or under 100 for this reason.
• Flicker Percentage: This is the most popular way of measuring flicker from a light source. I’ve included scores with dimmers without dimmer and while dimmed. There we're a few bulbs I missed this on as I returned the device I was using for testing purposes.
• Flicker Videos: I've taken slow motion videos of all the lights I tested
• RF Interference: Very few lights produce RF interference, however since I’m normally quite mindful of man-made EMF I wanted to find a light source that isn’t producing tons of RF for no reason other than sloppy engineering.

I’ve also written a guide on this as well if you’d like to check that out. It contains all the links for the best lights, as well as ideas for implementing light setups of your own.

How to Replicate Full Spectrum Sunlight Indoors

Here are some of my thoughts on the lights I tested:

• The Shanpu Z0850/55Pro and the GE Sun Filled bulbs are the best on the market right now. Here’s a comparison of these lights compared with the spectrum of natural sunlight:

• As you can see, the Shanpu Z085o/55Pro is a spectacularly realistic LED. However, it's kind of a pain to buy as 3rd party TaoBao agents aren't super user-friendly. They're also fairly expensive and the lumens per watt is lower than most other LEDs, so you need more of them to achieve a better lux level, which of course jsut raises the cost more.
• All in, you're looking at like $600 to put out 10,000 lux from these. However, this is very high quality light, with no noticeable flicker. If you like paying for the good things in life, this is it!
• The cheaper and more accessible alternative is the GE Sun Filled lights. At $8-10 a pop, higher luminous output and available on Amazon, they're a great option for someone looking to fill their home with more realistic light. A potential downside is that they do have invisible flicker a bit in the 120Hz range, which could potentially cause sensitive people issues. I personally use these lights and haven't noticed any negative effects, but that doesn't mean they aren't there.
• NorbSmile also uses the SunLike diodes in their bulbs, but their offerings cost more than GE and flicker more as well, so I don't really see any reason to purchase their lights. I did email them about the clicker, and they said they'd be looking into it.
• I was initially very excited about the Sylvania Natural bulbs given the claims and price point, however, I encountered several issues. They’re outright lying about the SPD these give off. The 8w, 11w, and 13w 5000K A19 bulb all have a generic blue pump phosphor blend SPD, as you can see below. I’ve emailed Sylvania asking for an explanation, and have yet to hear a response.

View attachment 37870

• I also measured 16 of the 8w 5000K bulbs, and found each one had a flicker rate of 12%. None of the other Sylvania bulbs had flicker, as advertised, so this was unexpected. This shows a pretty severe lack of quality control in my opinion, seeing as how one of the big advertising features of these lights is the low flicker rate and dimming capabilities.
• I tested several of the leading contenders for the low-blue light bulb market. I think dim, low-blue lights in the evening are important. However, I’m not a fan of red and orange lighting, I find them very unnatural and uncomfortable personally.
• All the warm low wattage LEDs I tested had an insane amount of flicker, so these were a no-go.
• The Bedtime Bulb is an interesting product, however I think they’re too bright for nighttime use, even the lower wattage version, and the custom phosphor spectrum they accomplish isn’t really that special.
• In the end, the low wattage incandescent bulbs are the best evening light option in my opinion. The 7w bulbs for example don't exceed 10 lux even at a distance of 2 feet, which is perfect for evening use.

My Setup:

Alright, I'll end this with my current office setup.

1. I've built two large DIY chandeliers with six GE Sun Filled bulbs and one 53w halogen each. Though I think I'd like to make another... This gives the room most of its lux.
2. I also have a floor lamp with three halogen BR30s pointing towards me for more full spectrum infrared exposure, it gives off a pleasant warmth at around two feet.
3. And finally, I have a 48" UV reptile light mounted to the corner of my ceiling molding, spraying the room with a trace amount of UV light.

Here's what I've ended up with:

View attachment 37871

And here are the spectral graphs from this setup:

View attachment 37872

Here's the info from the UV light output for those interested:

1 ft: 3.5 UVI
2 ft: 1.5 UVI
3 ft: 0.8 UVI
4 ft: 0.5 UVI
5 ft: 0.2 UVI

Well, I think that's about it!

One more shameless plug to the guide I wrote up about all of this:

How to Replicate Full Spectrum Sunlight Indoors

Hopefully you found this information useful! Have a great week!

Brilliant work! Thank you very much for this.

 

[Funnywhensunny]

Will you be selling your bulbs? I’m interested!

 

[johnwester130]

amazing

 

[TheSir]

Excellent research. Many will be finding this valuable.

 

[itchaboyagain]

Will you be selling your bulbs? I’m interested!

Boy I'd love to make some of my own to sell!

For now, these are all off the shelf products.

 

[sunny]

I was not familiar with that ge bulb. Thank you.

 

[Lollipop2]

Brilliant work! Thank you very much for this.

It seems like in the US Biden has banned incandescent and halogen lighting. Not sure when they will disappear but not too long from now. Long back I had made a post about the ban and what to do, but no one responded. This gives me some idea. I prefer incandescent but second best are halogen bulbs and have been using halogen as I can no longer find incandescent for a few years. Thank you.

 

[Lollipop2]

It seems like in the US Biden has banned incandescent and halogen lighting. Not sure when they will disappear but not too long from now. Long back I had made a post about the ban and what to do, but no one responded. This gives me some idea. I prefer incandescent but second best are halogen bulbs and have been using halogen as I can no longer find incandescent for a few years. Thank you.

@itchaboyagain this was meant to be a response to your OP - lol. Thank you again. Concerned about the ban..,

 

[miquelangeles]

Nice thread. I've also done extensive research and experimentation with light in the past year.
Regarding your office setup - with all those lights you are creating too many powerful electric fields that outweigh any benefits from the lights.
In the beginning you will feel euphoric and energized from the neuronal excitation caused by the electric fields.
A ~30 minutes exposure can be stimulating and beneficial, but over time you will get side effects from the induced intracorporal currents.
You should try to ground the floor standing lamp and the fixtures if possible. One way I can think of is to pass the light through a thin mesh dome made of metal and connected to the ground wire at the wall outlet.
Have you experimented with flicker-free incandescent light using 12 volt bulbs and DC transformers?

 

[itchaboyagain]

@itchaboyagain this was meant to be a response to your OP - lol. Thank you again. Concerned about the ban..,

I hadn't heard of that ban! Mind linking your post? I also find that concerning, as of infrared is completely pointless, it's ridiculous.

 

[itchaboyagain]

Nice thread. I've also done extensive research and experimentation with light in the past year.
Regarding your office setup - with all those lights you are creating too many powerful electric fields that outweigh any benefits from the lights.
In the beginning you will feel euphoric and energized from the neuronal excitation caused by the electric fields.
A ~30 minutes exposure can be stimulating and beneficial, but over time you will get side effects from the induced intracorporal currents.
You should try to ground the floor standing lamp and the fixtures if possible. One way I can think of is to pass the light through a thin mesh dome made of metal and connected to the ground wire at the wall outlet.
Have you experimented with flicker-free incandescent light using 12 volt bulbs and DC transformers?

Those are very good recommendations! I'll look into doing that and adding those recommendations to the guide.

Regarding powering resistive lights with DC transformers, no I haven't heard of that... Do you mind linking some information on the topic?

 

[itchaboyagain]

Those are very good recommendations! I'll look into doing that and adding those recommendations to the guide.

Regarding powering resistive lights with DC transformers, no I haven't heard of that... Do you mind linking some information on the topic?

Those are very good recommendations! I'll look into doing that and adding those recommendations to the guide.

Regarding powering resistive lights with DC transformers, no I haven't heard of that... Do you mind linking some information on the topic?

I'll have to check my office for fields too, I was so narrow focused on lux and spectrum realism I completely forgot about testing the fields with my meter... Doh!

 

[miquelangeles]

I've made the same mistake before, focusing on lux I was keeping the bulbs too close and got side effects from the electric fields. I mistakenly attributed them to the light initially. With incandescent the 50/60Hz AC flicker is inevitable, and despite the thermal inertia it is quite noticeable. You mention dirty electricity but it has almost no impact on flicker.
An incandescent or halogen bulb can be powered by AC or DC. With DC it will basically be flicker free, depending on the quality of the transformer.
It can be costly to get a good 120V or 240V DC power supply but you can use one or more 12V DC power supply with several 12V incandescent or halogen 100W bulbs.
A used Xbox power adapter for example costs $20, it is high quality with less ripple and it can give you 200W of DC power (it is rated 12V @ 18A).
Also look into water-filtered incandescent/infrared. It mimics the sunlight passing through the atmosphere which contains water. I found too much infrared to be very irritating. There are a few water-filtered commercial lamps available but you can DIY as well. The infrared absorption bands of water are in the 1000nm, 1200 nm, 1400nm and 1800-2000 nm. It will be much milder rich in orange and red spectrum and you can keep it very close to skin to penetrate deep into the tissues without overheating (but you need to reduce electric fields).

 

[Makrosky]

Nice thread. I've also done extensive research and experimentation with light in the past year.
Regarding your office setup - with all those lights you are creating too many powerful electric fields that outweigh any benefits from the lights.
In the beginning you will feel euphoric and energized from the neuronal excitation caused by the electric fields.
A ~30 minutes exposure can be stimulating and beneficial, but over time you will get side effects from the induced intracorporal currents.
You should try to ground the floor standing lamp and the fixtures if possible. One way I can think of is to pass the light through a thin mesh dome made of metal and connected to the ground wire at the wall outlet.
Have you experimented with flicker-free incandescent light using 12 volt bulbs and DC transformers?

Have you measured it with an EMF meter? Because electric and magnetic fields quickly dissipate with distance. It should be as simple as moving away the black standing lamp 2-3m away and the one on top also. Then it is safe. He will get much more EMF from the computer than from the bulbs. Touching a keyboard connected to cable to a computer will give you a way more powerful EMF than a few bulbs 3m away.

 

[itchaboyagain]

I've made the same mistake before, focusing on lux I was keeping the bulbs too close and got side effects from the electric fields. I mistakenly attributed them to the light initially. With incandescent the 50/60Hz AC flicker is inevitable, and despite the thermal inertia it is quite noticeable. You mention dirty electricity but it has almost no impact on flicker.
An incandescent or halogen bulb can be powered by AC or DC. With DC it will basically be flicker free, depending on the quality of the transformer.
It can be costly to get a good 120V or 240V DC power supply but you can use one or more 12V DC power supply with several 12V incandescent or halogen 100W bulbs.
A used Xbox power adapter for example costs $20, it is high quality with less ripple and it can give you 200W of DC power (it is rated 12V @ 18A).
Also look into water-filtered incandescent/infrared. It mimics the sunlight passing through the atmosphere which contains water. I found too much infrared to be very irritating. There are a few water-filtered commercial lamps available but you can DIY as well. The infrared absorption bands of water are in the 1000nm, 1200 nm, 1400nm and 1800-2000 nm. It will be much milder rich in orange and red spectrum and you can keep it very close to skin to penetrate deep into the tissues without overheating (but you need to reduce electric fields).

Very cool stuff! I'll keep looking but haven't found much on commercial water filtered IR, wouldn't happen to have links or names to drop, would you?

I'm curious what these look like in practice or how to make my own.

 

[miquelangeles]

Very cool stuff! I'll keep looking but haven't found much on commercial water filtered IR, wouldn't happen to have links or names to drop, would you?

I'm curious what these look like in practice or how to make my own.

DIY water filtered infrared/incandescent/halogen?

Has anyone tried to make one?

raypeatforum.com

Products

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www.hydrosun.eu

 

[miquelangeles]

Have you measured it with an EMF meter? Because electric and magnetic fields quickly dissipate with distance. It should be as simple as moving away the black standing lamp 2-3m away and the one on top also. Then it is safe. He will get much more EMF from the computer than from the bulbs. Touching a keyboard connected to cable to a computer will give you a way more powerful EMF than a few bulbs 3m away.

For light therapy I was using bulbs 1 ft away from my body.
itchaboyagain also mentioned he keeps them 2 ft away, which is too close unless you mitigate the electric fields.
The electric fields are drastically reduced when the appliance is grounded, but it needs to have a metal frame or case.

 

[Makrosky]

For light therapy I was using bulbs 1 ft away from my body.
itchaboyagain also mentioned he keeps them 2 ft away, which is too close unless you mitigate the electric fields.
The electric fields are drastically reduced when the appliance is grounded, but it needs to have a metal frame or case.

Putting them just 2-3-4 meters away would do it. The goal is to imitate sunlight during all day hours not to do light therapy. No need to redesign the whole thing.