dirt cheap T8 LED tube lights

anyone purchased cheap ones that cost like $7?
Because I just did and…

I’m not sure what to feel about this light I’m using.
It’s a noname brand and emits a neutral daylight tint (with a slight greenish tint)
And I’m getting weird eye sore headaches as well as nausea.

There is no PWM in the lights when tested with a phone camera.

Could it be poor CRI causing headaches?
I’ve been surrounded with cheap LED lights but this is the first time I’m feeling nausea with this light

Might be Gamma radiation. :Sp

Chances are that it is indeed PWM causing your symptoms.

To check for own with a camera you need to change frame rate or shutter speeds, normally phones do it automatically, or use a fixed value. Some also have an option to select the frequency of the grid (50 or 60hz) so the flickering of the fluorescent and other discharge lamps is not noticed in the videos. If your phone have selection of frame rate, try wit all of them (you probably did it already)

Mr DIY brand?

I have a few from this brand, but don’t feel anything like you described. But the output is on the low side though, and does have low CRI.

If it troubles you that much, swap it back with previous light. Not worth jeopardizing your health.

damn. yes it is Mr DIY LED lights ahaha

So far I’m okay now. Could be fatigue causing it.
I will consider swapping back when I get sick again next night lol

No point cutting electric bills when it’s cutting my life short

I setup a solar panel to audio jack for oscilloscope test and so far no pwm or even 50/60hz flicker but i do get a massive noise like frequency.
Maybe that’s the cause of it especially when I’m extra sensitive while fatigue

Always Low Prices :bigsmile:


Considered it might be a chemical problem? If they’re from China (what isn’t, these days?) there could be something volatile and unpleasant — anything — used as a plasticizer, or flux, or insulation, or potting compound, or “protective coating” — something that would come off into the air for a while.

Just speculating.

To check for PWM, it’s much more effective to rapidly wave a thin white card through the beam. I use an eye-measurement card from zenni, but a note card or business card or playing card should work too.

Here’s what ~500Hz PWM looks like with this method. This is the fastest speed my camera can detect, and even then it’s barely able to:

… and here’s what 4.5 kHz PWM looks like. I’ve never seen a camera which can detect this:

The fastest speed I can detect this way is about 20 or 30 kHz… which, oddly enough, is actually faster than selfbuilt’s sound card oscilloscope can measure.

I can detect up to around 2kHz direct from source, but this comes with pendarfluor-like coating which acts like a light capacitor (flux capacitor??).

I should try toykeeper’s method. You’re using manual setting on the camera? Can you share what to set e.g shutter, aperture etc?

I don’t know if it is the PWM that causes problem to you; Let’s say it is due to the PWM, do you feel uncomfortable while using any flashlight that has low PWM frequency for a long time?

Nope, this camera doesn’t even have manual settings. I just set it to over-expose, manually focus it to the right distance with a half-press, and try a few times until I get the timing right.

I don’t normally use a camera for this PWM method… I only took those pictures to demonstrate how it looks.


Or even waving your finger up and down in front of the torch. Most PWM is pretty east to see.

Quote >Or even waving your finger up and down in front of the torch. Most PWM is pretty easy to see. < quote

Make sure the torch is on :P

I see low pwm worse when there is some thing shiny around like the chrome faucet or doorknob.Don't feel badly though only really smart people are sensitive to lower PWM.

This is probably the closest answer to my question. (Thanks for making me realize this)
I’m probably sick from sniffing the heatwrap plastic that has been on the light. The smell is intense and it got stuck on the light for long as well as the indisposed trash can.
Well I threw the trash away and aired out the smell (as I have guests) and today I feel much better now. :slight_smile:

Here’s a review of T8 lamps — these aren’t “dirt cheap” but the price is coming down fast.
Some of these look quite likely worth getting for retrofitting:

Hands-on testing of popular LED T8 lamps and linear fixtures reveals promises and pitfalls
at this page: Hands-on testing of popular LED T8 lamps and linear fixtures reveals promises and pitfalls (MAGAZINE) | LEDs Magazine

See the original magazine link above for much, much more