[ferdiv]

Good evening everyone.

Why do Corona Rings "flicker" on camera/video? I believe this is because of their power-source no? Is there any way to capture quality photos with the rings not "flashing" as captured by the lense?

Thanks!
Fred

[ferdiv]

I actually just discovered... X3 running = flicker, X3 not running = solid lit rings

[ba ba boosh]

Cameras in general have a problem with capturing LED bulbs. That's why on any car with daytime running LED lights, they flicker when you record video. You could look at some Ferrari 458 videos on youtube, and the LED daytime running lights on the sides of the headlights flicker.

[buze]

The reason they flicker is that they, actually, flicker. LED are nor powered all the time like incandescent bulbs, you change the brightness of LED by turning them on/off very quickly at a certain frequency.
Any frequency over 60hz will be mostly invisible to a human (well not really but..) but you'll still have a fair chance to catch the moment they are off using a camera -- especially if it's daylight.

The process is called PWM aka Pulse Width Modulation. You pick a frequency, and you keep the LED on for a percentage of that time slot. In my experience, anything under 1000hz will still be visible in certain lights, and even to the human eye (enough to give headaches)

[Nham68]

PWM frequency of the driver circuit in a car is probably quite low , about 200 Hz so most won't see the flicker.. During a single switching cycle (5ms in this case), the duty cycle (on to off time) can be varied anywhere from 1% to >90% in theory, giving a huge dimming range. In practice, the duty cycle will be fixed about 50% for headlights. Rear light cluster might vary PWM e.g stamp on brakes, you want higher light output - increase the PWM in rear red LEDS.
Your interior LED ambient lighting works in the same way .. As you turn the wheel up and down on I drive , the duty cycle increases or decreases effectively increasing or decreasing the time current flows through the LED's, effectively increasing or decreasing the light output.

Compares to incandescent, LED give much better controlled light frequency output, though the biggest gain is electrical efficiency and longevity ..
Good for most , though some folks can be sensitive to particular light spectrum..

Not sure why it's different running vs non running ..

[ianfp]

I always thought that the daytime running lights (rings) not lit by LEDs and they are effectively a light guide with light source at the bottom of the unit.
I am not sure why they would flicker from a DC power source although I take the points made by buze and Nham68.

[c63er]

This is why led monitors give me headaches

[pokerface]

^this is why CRT monitors gave me headaches