flashing tail lights

[GT'S BiG FaN]

Hey guys
Stupid question
Why does some cars tail lights flash
Check this vid :
http://www.youtube.com/watch?v=tACtY7tsgg4&feature=related
(Sorry for my bad english)

 

[daan]

From my limited scientific knowledge

Most lights flash. We don't normally see it though as they're flahing very quickly and our eyes filter it out so we see a solid light. A camera, which catches single frames of time, can sometimes catch it when the light is "off", or refreshing, so it looks like it's flashing when viewed as a video. It's a similar thing to refresh rates on a monitor.

Probably...

 

[GT'S BiG FaN]

From my limited scientific knowledge

Most lights flash. We don't normally see it though as they're flahing very quickly and our eyes filter it out so we see a solid light. A camera, which catches single frames of time, can sometimes catch it when the light is "off", or refreshing, so it looks like it's flashing when viewed as a video. It's a similar thing to refresh rates on a monitor.

Probably...

Good one , Thanks

 

[Sniffs]

i have a couple theories, here.

1. loose or rattly wiring harness. i have that happen sometimes when a bulb socket is loose
2. LED's. since that's a Mercedes, the bottoms are most likely LED's

 

[Enigma]

I have noticed this on TV a few times, it seems to be newer cars with LEDs that do it.

One example is the ferrari 458 on the top gear track

video

Watch at 10 mins you will see the rear lights flashing on the straight, not sure what causes it but it does seem to only happen with LED lights

 

[the Interceptor]

Yes, this happens with LED lights. The older bulb lights are just being switched on or off and thus don't flash.

LED lights however are pulsed for a different brightness, so when filmed with a camera which captures discrete frames, these lights can flash because the camera catches them sometimes on and sometimes off, as daan explained. Example: you have one set of lights for driving and braking. When you do not brake, the LEDs are pulsed. This happens so quickly that the human eye can not distinguish the on-off-periods, so you just see a reduced brightness. When you brake and the lights come on, the LEDs are simply being tuned on all the time, so the light appears brighter to the eye.

 

[Jay.]

The Ferrari 458 brake lights have nothing to do with screen flicker/frame rate.
They are designed to flash under heavy braking. Just as many cars would flash thier hazards. Many modified police pursuit vehicles are fitted with lights like this already. The Mercedes in the video however looks like it could have some kind of wiring fault. No other brake lights showed and it looks to me as though he was accelerating, not braking.

There are also aftermarket '458 Flashing Brakes' conversion kits available for many cars with standard bulbs/LEDs.

 

[Giancarlo]

It's a German car. Therefore, the tail lights are broken.

 

[Jay.]

It's a German car. Therefore, the tail lights are broken.

PMSL! 👍

 

[Keef]

The Ferrari 458 brake lights have nothing to do with screen flicker/frame rate.
They are designed to flash under heavy braking. Just as many cars would flash thier hazards. Many modified police pursuit vehicles are fitted with lights like this already. The Mercedes in the video however looks like it could have some kind of wiring fault. No other brake lights showed and it looks to me as though he was accelerating, not braking.

There are also aftermarket '458 Flashing Brakes' conversion kits available for many cars with standard bulbs/LEDs.

Not quite. Lots of European cars have had brake lights that flash during extreme braking, it's been around for years. The Top Gear examples occurred while the car was stationary - note the TAIL lights, not the brake lights, and the front running lights are shown flashing - and while it was cruising down the runway, neither case involving panic braking. Likewise, the SL is obviously not panic braking though its brake lights will flash when that happens.

See Interceptor's post for the real reason, and read the thread before you post:

Yes, this happens with LED lights. The older bulb lights are just being switched on or off and thus don't flash.

LED lights however are pulsed for a different brightness, so when filmed with a camera which captures discrete frames, these lights can flash because the camera catches them sometimes on and sometimes off, as daan explained. Example: you have one set of lights for driving and braking. When you do not brake, the LEDs are pulsed. This happens so quickly that the human eye can not distinguish the on-off-periods, so you just see a reduced brightness. When you brake and the lights come on, the LEDs are simply being tuned on all the time, so the light appears brighter to the eye.

 

[motortrend]

I saw that in a 997.5, the one with the LEDs. But it was during launch control as I remember, and it was a video. Not sure if it does it all the time on camera.

 

[Pupik]

Yes, this happens with LED lights. The older bulb lights are just being switched on or off and thus don't flash.

LED lights however are pulsed for a different brightness, so when filmed with a camera which captures discrete frames, these lights can flash because the camera catches them sometimes on and sometimes off, as daan explained.

Older filament bulbs do "flash" as well, but at a different cycle rate that is imperceptible to the human eye. I took this photo at night with a tripod, and slowly panned (rotated) the camera during the entire 3.2 second exposure:

You can see that the tail lamps, street lights, and other bulbs do indeed have a cycle rate/Hertz when you smoothly pan the image to pick up all light coming into the image sensor on the camera. You'd get the same effect if you videotaped (or equivalent) a TV set while it was broadcasting something or playing a movie due to its frame rate or camera rate. A similar phenomenon is also visible when you see a wheel moving, and it suddenly appears as if its not moving, or even appears to be moving backwards (even though the vehicle is moving forward). Your eye and brain can only process a certain amount of movement at a time.

 

[Stotty]

Not quite. Lots of European cars have had brake lights that flash during extreme braking, it's been around for years.

Hmmm, I've not seen this at all in the UK, or whilst driving in France, Switzerland, Italy or Germany.

I have noticed some modern European cars now have a feature where the hazzard warning lights flash under prolonged, heavy braking (eg; performing an emergency stop on a motorway). But I've never seen the brake lights flash.

The SL video clip above looks like an electrical fault to me... Mercedes have a bit of a reputation for suspect electrics at the mo.

 

[motortrend]

Check that one out after the 1 min mark, or watch it completely, it;s worth it. There is also a flishing there, however there isnt on other porsche 911 vids i saw so it might be the camera or it might be a faulty car. Another thing, i only saw them flash whn not under heavy braking like in that video, but they did not flash on the launch control video i saw, so it may have something to do with the braking intensity

 

[Sniffs]

i can see this LED frequency shake with LED fairy/Christmas lights if I glance away, then back. they've got a point about the video thing, though. it's a cheap way to check your remote controll batteries are decent (use a digital cam with a vid screen, and run the business end of the remote. the IR LED's will flash)

 

[Enigma]

The SL video clip above looks like an electrical fault to me... Mercedes have a bit of a reputation for suspect electrics at the mo.

Its not an electrical fault the Ferrari does the exact same thing, its related to filming LED lights.

 

[harrytuttle]

You're forgetting the obvious fact that LED's are totally different from incandescent elements. LED's can illuminate and darken almost instantly. Incandescent bulbs will dim slightly. At the same AC cycle, the incandescent bulb will appear to be on for much longer than the LED. At lower rates (20Hz or less) this is very clear to see, as the LED will blink and the incandescent will appear to pulse.

 

[sems4arsenal]

Sorry for the Bump Guys ,but I was searching regarding this Subject on Google (should have known I'll return here ) .

Anyway I just wanted to confirm because some Friend asked that this only appears on Camera having seen it happen Yesterday on a 2012 GTR front LED (video)and Jeremy's Aventador Front lights (Apolgiez for the Bump again )