LED light vs. attracting insects

I didn’t notice this before, but “close to zero blue” and “ultra high CRI” are mutually exclusive. :wink:

No, it depends entirely in the color temperature. At <=2000K there is basically no blue content in the light. You can check this by measuring the cri and spectrum of a candle (see here).

Normally the lower the CCT, the less blue light there is. However, this is not always the case. I’ve measured 3000K lights with more blue light than 4000K. Even lights of the same temperature can have very different amount of blue lights. From my anecdotal data, high cri lights of the same CCT emit less blue wavelengths because less blue light gets through the thicker phosphor without being converted to other wavelengths. The E21A 2000K measures less than all other similarly warm light sources I’ve measured. It contains less blue wavelength than a Phillips 2400K incandescent bulb that I measured. Though a candle light might contain a bit less blue than the E21A 2000K.

High CRI sunlight is not only high in Blue it is also high in Green. Sunlight tint is Above BBL that is based on Incan.

High CRI incandescent is much lower in blue and also lower in green than sunlight. Incan tint is ON the BBL

on this graphic, thanks to maukka, we can see the 3 blue dots above the BBL, that represent sunlight, and the one blue dot on the BBL, far right, for incandescent CCT and Tint. Both incandescent and Sunlight are 100 CRI, but Sunlight is bluer and greener… see what I mean?

both sunlight and incandescent are High CRI, but they are totally different Kelvin Color Temperature, sun being bluer, and have totally different Tint, sun being greener

its much easier to fall asleep after exposure to incandescent, than after exposure to sunlight, due to suppression effect of blue light on melatonin

and yes, yellow and red lights do not attract bugs the way blue light does, but a moth will still fly into a candle flame :wink:

Yes, that's all true, but a bit beside the topic here?

The BBL is only used as a reference for low CCTs.

How do you measure? There is always soms variance between individual LEDs.

Yes, if you take the black body spectrum as the reference, it is always CRI 100 whatever the CCT but the spectrum varies with the temperature.
A CRI100 light can have a lot of blue light with high CCT and zero blue light with very low CCT.
Black body visible spectrum at different CCT :

Using a Sekonic C-800-U. I’ve taken probably over 1,000 measurements of various light sources.

There are some slight variations between LEDs of the same flux and tint bin, mainly CCT and DUV differences but usually not a whole lot and amount of blue light is pretty similar.

you did not marvel at the brilliance of my repartee? lol!

short version

1. more insects are attracted to cool lights that have blue spectrum outputs

example, typical 6000k Cool White LED
.
.

2. less insects are attracted to warm lights, that do not have blue spectrum outputs

example, typical 3000k Warm White LED

you mean less blue spectrum output. Some 3000K I’ve tested have quite bit of blue output.

Thanks
Can you share specific examples of no blue light hazard 3000k w high cri?

Eg How are the 3000k High Cri 219c, 219b, sst, lh351, e21a?

There are no 3000K with no blue light. Even E21A 2000K has some blue in it but it’s less than incandescent bulbs. Here are some of the warm white LED flashlights I’ve tested. I also tested a bunch of LED strips and light bulbs but I have no idea what emitters some of these use so I’m not going to post them.

How about monochromatic LEDs?

Do they have no blue lenght at all? Red is working great in terms of insects but how about green? Amber?

Now I’m curious.

Do we need to really aim for “no blue” or we just need to produce significantly less blue than whatever your neighbors are using?

Say, my neighbors are using 70 CRI 6500k light while I’m using 90 CRI 5000k. How much less insects I would attract compared to the neighbors? Assuming both they and I operate the light at the same time.

I think it’s more about your comfort when walking and holding/wearing a light. It does make a diffrence if you feed like a target for 100 000 bugs, or not. At least this is how this thread started…

You’re right that the diffrence in white light may be neglible at least to those working as blue light+ thru phosphor layer.

thanks for sharing your tests

another question
I know that the 4000k N219b is some “medical” flashlights, claim “No Blue Light Hazzard”

I dont know what that means… since as you say, there IS some blue light.

I suggest you do an experiment with two of your own flashlights… stand them up outdoors, a few feet apart, and watch to see which one attracts more bugs :slight_smile:

“I don’t have to run faster than the bear. I just have to run faster than you.”

It’s all relative. 6500K vs 5000K, bugs will go to the former. 5000K vs 2200K, again, bugs will go to the former. 2200K vs monochromatic amber, yet again, bugs will go to the former.

There might still be blue light in X, but as long as X has less blue light than Y, they’ll head on over to Y instead.

It certainly has a blue spike (= not free of blue light hazard) but probably/hopefully limited.


I guess that the more the blue spike curve match the blue light hazard function (curve) the more it is considered to be blue light hazard.

thanks Tally-ho, I like that chart

fwiw, here is a light that claims
the output has an RG0 rating to eliminate blue-light hazards
https://www.amazon.com/Nitecore-MT06MD-Flashlight-Batteries-Organizer/dp/B06XCKNFSN

here is a similar light, without the “no blue-light hazzard” marketing spin
https://www.amazon.com/LUMINTOP-Penlight-Rendering-Diagnostic-Waterproof/dp/B07C9XP692/

That’s advertisement BS or they have no idea what they talking about. 4000K is very high in blue light content unless it uses a violet pump but violet light is higher energy so it might contain other dangers that we are not yet aware of. 3000K would be the cutoff for acceptable level of blue light IMO. However, I don’t doubt 4000K 219B 9080 makes for a good medical light due to it’s very good color rendering and near BBL tint, and is still a good NW.

One thing I notice is that when I get blasted in the eye by a 2000K, it is less painful and it takes much less time for my eyes to readapt to the darkness than a cooler temp light.