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amluto

No.

The article is light on details, but:

> A simple device that makes LED lights flicker at a very high frequency that is imperceptible to the human eye

> shutter, which needs to be lightweight and agile enough to blink about 150 times per second.

Subjecting an entire city to 150 Hz flicker is not even remotely acceptable. IMO this needs to comply with IEEE 1789.

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Also - it feels like it's not 'simple'. And I doubt it will ever be implemented.

Why do you think 150Hz is unacceptable? People used to watch 50Hz TV, and weren't bothered too much. And San Jose used to use 60Hz flickering streetlights (sodium? not sure) to reduce light pollution for Lick Observatory.

IEEE 1789 lays a lot of that out. In a nutshell, LEDs are harsher.

because tvs used phosphors it isnt really on/off 50hz just a slight light dip.

If you look at high speed footage of a CRT monitor, you'll see that only a few scan lines are lit at a time.

https://www.youtube.com/watch?v=3BJU2drrtCM&t=150s

because of the high framerate you are seeing increased apparent contrast between actively lit and fading phostphors.

Pre-LED stadium lights do indeed flicker pretty egregiously, but, when correctly installed, they would be balanced between all three phases, so at least the average illumination was roughly constant.

I don’t know why TVs weren’t headache-inducing. Certainly old CRT computer screens were extremely unpleasant to look at at lower refresh rates.

Why not?

Because of the rather well documented effects on health and visual performance.

When a bright light is extra annoying to light sensitive eyes it's because the lamp is actually blinking at a high frequency.

Because people can see the flicker. It becomes apparent with object moving quickly across your visual field (including waving your hand left-right). It creates big issues with photography and video recording.

Because cities are made for people to live in.

Even flicker that isn't perceptible to humans is still associated with increases in all sorts of things including eyestrain, headaches, anxiety, migraines, and seizures.

150Hz is well below the human perceptual threshold but still within the range that can cause problems.

Thank you!

Flicker at certain frequencies isn't noticeable to humans in isolation. Add in other types of flicker (lights at other refresh rates, monitors, TV's, etc) and you can see the interference between them.

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