LED lighting strip under cabinets

[Mike.. . . .]

When I scrape carrots with fast motion under the LEDS I see multiple images of blade. Some feature of LED no doubt?

[Andy Burns]

Stroboscopic effect, pretty standard for many types of non-incandescent lighting that run at low (i.e. mains) frequency ...

[John Rumm]

Going for a switched mode LV power supply for them would probably fix that - since the output frequency is often into the kHz...

[Mike.. . . .]

Yes, incandescent, will of course, by its nature, not allow pulsing to show up. Interesting effect.

[The Natural Philosopher]

well it does, but its much less.

Try feeding a photocell into a scope..under artificial lighting there is a massive 100hz ripple.

[meow2222]

Unless you scrape those carrots hella fast

NT

[Dave Plowman (News)]

But LEDs run on DC?

[Dave Liquorice]

Or pulsed DC. Quite often to aid light output versus cooling requirements they are fed very high current pulses on a low duty cycle.

The fact that the OP sees multiple blades shows that there is some form of flicker in that light source.

[Andy Burns]

For the cheap ones that's just rectified mains.

[Adam Aglionby]

Which results in same average brightness, wish someone would tell the car tailigfht deisgners as wel.

Cheers Adam

[Dave Liquorice]

Agreed, I hate the multiple images that some LED vehicle lights produce. They don't seem as common as they were. I wonder if they have just upped the frequency, shaped the waveform or gone to true DC?

I have noticed that some new cats eyes around here are the new(*) "electronic" flickery things. Get a very distracting flicker from them right in the periphary of my vision.

(*) Well about 10 years old "new" there was a stretch of trial road near here but they didn't last long before they failed and where they have been replaced it's with conventional passive ones.

[ARW]

I will have to have a look at the trial section near me (about a mile away but I seldom use that road) and see if they are still working. I just loved turning the headlights off when driving that bit of road.

[polygonum]

Wondering if, rather than flicker frequency of any sort, it is more like what a Muybridge effect?

With LEDs you have, I guess - if it is like ours, got a series of individual light sources. So anything moving through that actually goes between bright and dark. Your eye will tend to 'notice' when it is bright and miss it when it is not. And that would end up looking a bit like a stroboscopic freeze-frame effect.