We need to talk about Olight

[jon_slider]

it's the PWM?

yes, sort of

PWM is one kind of flicker

it looks more like these two examples, where the LED is turning (almost) all the way off and on:

For some people PWM only means obviously visible flicker.

Here is an Eagtac. It is not using full PWM, but it has a pretty high Flicker Index:

It is using 54% dimming between full power pulses, at a relatively slow speed of 240 cycles per second.. It is a type of Flicker, but not exactly correct to call it PWM. That flicker might not be obviously visible to most people.

 

[Schokokeks]

yes, sort of

PWM is one kind of flicker

it looks more like these two examples, where the LED is turning (almost) all the way off and on:

View attachment 74235
For some people PWM only means obviously visible flicker.

Here is an Eagtac. It is not using full PWM, but it has a pretty high Flicker Index:
View attachment 74236

It is using 54% dimming between full power pulses, at a relatively slow speed of 240 cycles per second.. It is a type of Flicker, but not exactly correct to call it PWM. That flicker might not be obviously visible to most people.

Ah, okay. So PWM is maybe flicker when it's used to lower the output, but this is more just the overall rate at which the power is supplied to the LED? Ergo, PWM is a specific KIND of flicker, but flicker is overall more just a more generalized "feature"?

 

[WarriorOfLight]

yes, sort of

PWM is one kind of flicker

it looks more like these two examples, where the LED is turning (almost) all the way off and on:

View attachment 74235
For some people PWM only means obviously visible flicker.

Here is an Eagtac. It is not using full PWM, but it has a pretty high Flicker Index:
View attachment 74236

It is using 54% dimming between full power pulses, at a relatively slow speed of 240 cycles per second.. It is a type of Flicker, but not exactly correct to call it PWM. That flicker might not be obviously visible to most people.

What are you using as measuring device, and how many samples per seconds are you measuring with this measuring device.
I am asking because picture #2 and #3 are looking kind of strange to me.

At least everything over 1000Hz (ever lower values like 300Hz) can not be recognized by the human eye. At least I do not know any scientific publication that says that a human eye is able to do that.

That "magic" 100Hz (2x 50Hz) and 120Hz (2x 60Hz) are the area that still might be recognizeded by he human eye... A normal incan buld used on the 110V in the US is flickering @120Hz, in Europe on 230V @100Hz.

 

[dc38]

What are you using as measuring device, and how many samples per seconds are you measuring with this measuring device.
I am asking because picture #2 and #3 are looking kind of strange to me.

At least everything over 1000Hz (ever lower values like 300Hz) can not be recognized by the human eye. At least I do not know any scientific publication that says that a human eye is able to do that.

That "magic" 100Hz (2x 50Hz) and 120Hz (2x 60Hz) are the area that still might be recognizeded by he human eye... A normal incan buld used on the 110V in the US is flickering @120Hz, in Europe on 230V @100Hz.

1000Hz isn't high enough to be imperceptible unless the light is ridiculously intense. A gen 1 4sevens preon has pretty high pwm on its low mode, but is still nauseating to use for extended periods of time. It generates a visual effect of looking through a screen door while moving...you can see the image but there is something intermittently interrupting the image.

if you want evidence that the human eye can actually see the flicker into thousandS of hz, just take any flashlight with a known pwm, turn it on to a pwm mode, and wave it in front of you at a near perpendicular angle and observe the skipping of the light source. when the skips become almost indiscernible, that's the bare minimum the pwm should be for you.

 

[dc38]

Ah, okay. So PWM is maybe flicker when it's used to lower the output, but this is more just the overall rate at which the power is supplied to the LED? Ergo, PWM is a specific KIND of flicker, but flicker is overall more just a more generalized "feature"?

Pwm is a very fast strobe, intended to emulate continuous lighting. it works the same way with sound, when a frequency gets high enough that it sounds uninterrupted. Bad pwm is like the brrrrt from an A10 Warthog, good pwm is like average human vocals.

 

[WarriorOfLight]

1000Hz isn't high enough to be imperceptible unless the light is ridiculously intense. A gen 1 4sevens preon has pretty high pwm on its low mode, but is still nauseating to use for extended periods of time. It generates a visual effect of looking through a screen door while moving...you can see the image but there is something intermittently interrupting the image.

if you want evidence that the human eye can actually see the flicker into thousandS of hz, just take any flashlight with a known pwm, turn it on to a pwm mode, and wave it in front of you at a near perpendicular angle and observe the skipping of the light source. when the skips become almost indiscernible, that's the bare minimum the pwm should be for you.

I will not 'hijack' this topic. But I really have doubts that the human eye is able to recognize PWM frequencies that >1kHz range. Like I said there are no scientific / medical publications.

The LED flashing lights mostly use PWM that is far away from 1kHz.

The only possible thing that is the case is when you move the PWM source i.e. from left to right and close the eyes to reduce the incoming light than you may recognize flickering.

When I also see the pictures that Jon was taking my guess is the cutoff frequency of the measuring device was reached. The simpelst way is using an oscilloscope with a BPW34 photo diode. That is an optical detector for less than a dollar. And even the a simple oscilloscope has a cut off frequency of at least 1MHz.

For me the picture #2 and #3 are more looking like a problem with the Nyquist–Shannon sampling theorem.

but I guess this discussion should be stopped here. We are talking about Olight...

 

[jon_slider]

Flicker Index tests using Opple 3:

New Mod:
Olight Auspicious Clouds i3e, w DeDomed 4500K 519a w pebbled Tir: