Kobo forma screen flickering/pwm issues

[John F]

Originally Posted by JSWolf

If you replied yes in the poll, please explain what it is you are seeing or what is happening. Please be as specific as possible. Thanks.

What about the no votes?

[meeera]

Originally Posted by koboyedi

Wow, this discussion is drifting towards flat-earther territory,

I agree, though perhaps not quite in the same way that you mean this.

Originally Posted by koboyedi

It's classical physics guys!

It's the physics-biology interface. Which is complicated, but testable. "BUT IT'S OBVIOUS!!" is not science.

Originally Posted by koboyedi

There is not a shred of doubt PWM has an effect on people and yes (!), you don't get to have an opinion on that, since it's not up for debate. The only question is to what extent people are affected.

Absolutely no one has disputed the fact that low frequency PWM can have a biological effect on people. What is in debate is whether PWM at 1000 Hz can have a biological effect on people. So far, no evidence has been presented of this. Again, feel free to present some, if you can find it.

I have no doubt that knowledge of its existence can have a psychological effect, and there is very good evidence for the nocebo effect as a phenomenon. It would take some good science to winkle that effect out, and I've seen none.

[DNSB]

Originally Posted by koboyedi

Wow, this discussion is drifting towards flat-earther territory, so this has to be said:

It's classical physics guys! There is not a shred of doubt PWM has an effect on people and yes (!), you don't get to have an opinion on that, since it's not up for debate. The only question is to what extent people are affected.

Could you point out where someone has said that PWM does not have an effect on some people?

What appears to being said is that the Forma uses 1KHz PWM. So far I haven't seen a study that shows any effect from PWM at that rate -- the highest rate I saw in a study was one that showed a small percentage of the participants could notice artifacts from PWM at 400Hz in saccade (rapid eye movements). One of the tests involved a single dot on the screen which seemed designed to maximize the ability to detect any effects.

Looking at quite few of the original complaints, they seemed to involve Samsung AMOLED phone screens. The majority of those early screens used PWM rates below 100Hz. For example, the Samsung A10 which uses a 77Hz PWM rate.

Not taking the PWM rate into account is similar to arguing that since I can see flicker in a 10fps video, I should be able to see flicker in a 200fps video. After all, they both have flicker.

Originally Posted by koboyedi

Next to this, most people who experience issues are not even aware their problems could be caused by something they don't visibly notice, hence the true number of affected readers is 'very likely' much higher than any forum poll could suggest.

To sum it up, there is no question if there is a problem, only how serious it is.

It's hard to find a proper double blind study. The only one I could locate that came even close indicated that while ~10% of people do notice effects from sub-100Hz PWM, that a similar percentage (~8.6%) complained about eye strain and headaches from a DC dimmed display. Google Scholar really needs to improve their search algorithms.

[JSWolf]

Originally Posted by John F

What about the no votes?

Why would someone who is not seeing flicker or having eyestrain be asked to explain that? They see no flicker and they have no eyestrain.That's the explanation.

[meeera]

Originally Posted by JSWolf

Why would someone who is not seeing flicker or having eyestrain be asked to explain that? They see no flicker and they have no eyestrain.That's the explanation.

Let's be very clear: no human person is seeing flicker on their Formas.

[John F]

Originally Posted by JSWolf

Why would someone who is not seeing flicker or having eyestrain be asked to explain that? They see no flicker and they have no eyestrain.That's the explanation.

Originally Posted by JSWolf

If you replied yes in the poll, please explain what it is you are seeing or what is happening. Please be as specific as possible. Thanks.

I don't think that it follows that if someone voted yes, that they can "see" the flicker; they may not "see" the flicker, believe it is causing eyestrain, and voted yes. Other things could be causing the eyestrain, as others have mentioned.

And vice versa... People may have voted no, still have eye strain, and believe that the eyestrain is not caused by the flickering.

I interpret the poll as taking the flicker as a given (whether you can see it or not).