Testing and Eliminating flicker with my Radex Lupin flicker meter.

Testing and Eliminating flicker with my Radex Lupin flicker meter.

After a lot of searching and waiting, I finally found an affordable handheld flicker meter! While many commercial flicker meters from UPRTek and HopooColor are over $1000, I wanted to find something affordable that more people can take control of flicker in their lives. I know not everyone will want to make my DIY flicker meter for less than $50.

I have written extensively about flicker for the Alex Fergus blog, my own blog, and on many social media posts. The key is to avoid strong invisible flicker from light bulbs that might lead to eyestrain, fatigue, dizziness, headaches, and distraction. Like any poison, high "doses" of spending a lot of time under flickering lights

The key areas to avoid flicker:

1. Computer monitors.

2. Household and workplace lighting.

3. Red Light Therapy Products (if they are aimed at the eyes/face).

I am using and testing this flicker meter called Lupin Radex, their distributor sells directly on Amazon. It is only $125! A fantastic price!


radex lupin affordable low cost flicker meter

So, how much can we rely on a flicker meter that is only $125? Well I use it to test my household lights, my GembaRed lights, and my new pulsed light product. Using some cross-comparisons and common sense shows that this is a very nice flicker meter for the price!

Household Lights Mitigation:

Changing my lightbulbs to WaveForm Lighting bulbs.

I recently changed my bedroom and bathroom lights over to bulbs from WaveForm Lighting.

waveform lighting light bulbs low flicker low kelvin

They check all the boxes for an ideal LED Light:

1. Low Kelvin - 2700K and 3000K options ensure there is low blue and a more natural spectrum.

2. High CRI  (color rendering index) - make sure the spectrum is full of color, not just blue.

3. High R Value - ensures that there is a good proportion of red to balance the spectrum and make colors more vivid.

4. Low Flicker - key for eye comfort and safety.

So how well did we do with the changeover?

 waveform lighting light bulb low flicker measurement

We can see that my old bulbs flickered at 16.6%, while the new Waveform Lighting bulbs flicker at less than 1%. Really nice improvement!

Replacing a fluorescent tube light for low-flicker LED strip lights:

I have always hated the flourescent tube over my pool table. So I decided to replace it with a LED strip light powered by a low-flicker constant-voltage driver.

I got the LED strip and driver from https://www.ledsupply.com/

So how does my LED strip compare to the old fluorescent tube?

fluorescent light flicker led strip light flicker

So we have a drastic improvement from 39% flicker from the fluorescent tube down to only 1.5% flicker from the LED strip lights! Another great improvement!

Pulse Testing:

I recently assembled a high-intensity LED light. The light is so intense that it heats my skin rapidly when I applied the light. So I added a pulse module to it so that my skin can cool down between pulses and I can tolerate the treatments better. That is the true reason for using pulsing, is that it is a thermal management system for high intensity lights.

GembaRed MegaBuster Prototype high intensity pulsed red light therapy

The problem is that I wanted to verify the pulse rate, so I did it with my new Radex Lupin as well as my DIY flicker meter.

 Pulse Rate measurement red light therapy

Here we see the pulse rate is 11Hz, and both the Radex Lupin and my DIY flicker meter agree on this number. This is good to know, however it is disappointing because I specified 10Hz to the manufacturer. This is why we must always test with 3rd party equipment, we can never trust what the manufacturer claims.

This does show that the Radex Lupin is a useful meter for both flicker frequency, pulse rate, and flicker percentage. This makes it a very useful meter for testing lights in the red light therapy industry.

Red Light Panel Testing:

Finally we test our GembaRed light panels with the Radex Lupin meter. As we already know, all of our GembaRed panels have been professionally measured to be about 1% flicker. So what does the Radex Lupin meter say?

GembaRed light low flicker measurement

Here we see all of the GembaRed panels flicker at less than 1%! Really nice, since it is fairly close to the measurements that we get from the professional lab. This really validates that the Lupin Radex is a good pick for home-use. And it confirms the safety and quality of all of our GembaRed light panels being low flicker!


The Radex Lupin is an impressive flicker meter at a great price, and conveniently available on Amazon. This is a great way for people prone to eyestrain to test their computer monitors, home lights, and red light therapy lights to see if flicker could be the cause of their distress. And it can even help Red Light Therapy enthusiasts test for pulsing and flicker in their lights!

Supplemental Reading: Testing flicker and PWM on Red Tactical Flashlights!