Why do conversations on LED flicker consistently miss the key point?
Today’s quality LEDs offer superbly low flicker levels; so why does it still cause debate? Lumilow’s Managing Director, Andy Chell seeks to sort out fact from fiction.
I have sat back and watched many discussions, across social media or at industry events, regarding the subject of flicker in LED lighting. The reality is; I have wondered what I am missing. When I look at every LED light, I never see what everybody else seems to be reporting. The stories seem endless, reports come in that LED flicker is a massive problem, but frankly I don’t notice it. I’ve read strange assessments; if you hold your mobile phone camera to the LED light, you will see the flicker via the strobing on the camera screen.
What possible relevance to the real world of LED lighting can this have? Surely no one actually does this in a practical way?
My point isn’t to diminish the importance of the correct levels of glare, nor to ignore the fact LEDs have to perform to the highest standards, in the workplace or the school. What concerns me are the tiresome examples of LED scaremongering that still seem to exist. When actually, far more pressing flicker worries are out there, in our children’s education establishments, nationwide.
Flicker: fact vs fiction
If LED flicker is such a big problem, why is there not a similarly-minded campaign to outlaw all old style electro-magnetic switch start luminaires, which flicker appallingly? The arguments seem one sided and biased against LED.
Lux has recently published a very good, balanced article on the issues of flicker. It explains that 80% of UK school children are ‘at flicker risk’ from old lights; four fifths are having their learning impaired and are at risk from anxiety, migraines, headaches and even dyslexia from flickering lighting, an expert scientist has warned. Note the cause: ‘old lights.’ Not new LED alternatives. This is my concern; why the constant emphasis on LED flicker, when nowadays LEDs offer superbly low flicker levels, yet legacy 100Hz equipment in schools, which flickers and can be drastically improved with modern LEDs, barely merits a mention.
The Lux article quotes Arnold Wilkins, Emeritus Professor at the University of Essex and a leading expert in photosensitivity and physiology. He says; “Unfortunately 80% of our schools are still lit with lighting that flickers at 100Hz.
“It causes headaches and it causes anxiety. It’s there all the time. Whether it impairs their learning, seems to me to be plain enough.” Why on earth is this not the story we are shouting about?
In another example, we have known of the danger of switch start fluorescent lights over rotating machinery for many years. The strobing effect, at the same frequency as the rotation of machines, appears to make them stationery; in actual fact they are still turning. High frequency control gear, typically running at 27KHz was the legacy solution to this. But now LED technology has improved and become more efficient, the business case for LED with regards to health and safety as well as energy efficiency in this scenario is well proven.
I’ve no issue with ensuring, day in, day out, that LED flicker is minimised, and that we deliver the best LEDs, fit for purpose, that we as an industry possibly can. But I do object to poor reporting, which shouts about LED flicker, but ignores far more potent risks, that we can actually solve with LEDs.