Kobo forma screen flickering/pwm issues

[Tokei]

Originally Posted by jackie_w

How many of these "many people" have seen an actual Forma and not just the contrived videos?

I owned a Forma for several weeks and sold it due to the PWM issue. I ultimately ended up buying a Kindle Oasis 3.

The Forma was in my view better than the Oasis in many aspects. The bigger screen while weighing the same is one or that I preferred the haptics of the grippy plastic over the pointy, cold and slippery metal of the Oasis. But I was irritated, as I wrote in a post before, by the Forma’s lighting that I perceived as less calm than a non PWM-screen. I compared the device side by side in various lighting conditions (sunlight, artificial light, lights off) and also “blind-tested” with my wife and we agreed that the non-PWM screens of the Kindle PW and Oasis are easier on the eyes.

I cannot tell you if that is my mind playing tricks on me or another factor that has nothing to do with PWM. But in the end, I didnt care because it is my own subjective perception that counts in the end when making a buying decision.

So my recommendation to all who think about the Forma is to try it out, compare it and trust your own perception and opinion. You like it? Keep it. Dont like it for whatever reason? Sell it and get a different one.

[koboyedi]

I've now ordered a Libra (gets here after the weekend) and will then compare it with the Forma. I'm really curious how these two compare hands on side by side, since I'm currently super-biased in favour of the Libra while the spec sheets favour the Forma.

[filmo]

I was a motion picture cameraman. Film speed standard was 24 frames per second. That isn't fast enough to eliminate flicker so each frame was projected twice by a butterfly shutter. High speed 16mm motion picture camera with pull down claw film advance and registration pin holding film during exposure were limited to 400 fps but using rotating glass shutter much faster frame rate is possible. I,000 fps +, because film didn't need to stop for each frame exposure.

[JSWolf]

How many of you who are complaining about the flicker has seen the flickrer on an actual Forma? Videos do not count.

[koboyedi]

Originally Posted by JSWolf

How many of you who are complaining about the flicker has seen the flickrer on an actual Forma? Videos do not count.

You can't see it with the naked eye but that's not the point. The point is I want a device that it as less stressful to the eyes as possible and with PWM it doesn't matter if you can see the flickering.

That's what happens when you sit in front of a computer screen and read for hours, it also doesn't flicker 'visibly' but it's still there and messes with your eyes as you read long text.


This is how your eyes normally read letters on a continuously lit display. It's one smooth motion.


This is how your eyes read letters with PWM LEDs. In staccato, the opposite of smooth.


Which display seems less stressful to your eyes?

[JSWolf]

Originally Posted by koboyedi

You can't see it with the naked eye but that's not the point. The point is I want a device that it as less stressful to the eyes as possible and with PWM it doesn't matter if you can see the flickering.

That's what happens when you sit in front of a computer screen and read for hours, it also doesn't flicker 'visibly' but it's still there and messes with your eyes as you read long text.


This is how your eyes normally read letters on a continuously lit display. It's one smooth motion.


This is how your eyes read letters with PWM LEDs. In staccato, the opposite of smooth.


Which display seems less stressful to your eyes?

Have you used a Forma and gotten eye strain? What I want to know is PVM a real problem or is a big deal being made by what some perceive as a problem that's really not a problem.

[koboyedi]

Sorry, I've only used mine briefly since it's currently on route to be replaced because of other screen lighting issues.

[JSWolf]

Originally Posted by koboyedi

Sorry, I've only used mine briefly since it's currently on route to be replaced because of other screen lighting issues.

When you do get your replacement Forma and you've used it enough, please let us know if the "flicker" is a problem. I want hard facts, not what some may think without really knowing.

I have not read of anyone saying they get eyestrain from using a Forma. If there is no perceived flicker, there's no eyestrain (going from what I've not read). If there was eyestrain with a Forma, I would have expected to read about it on MR by now.

The way I'm reading it, some are reading about PVM and thinking they may be seeing flicker when there is none. If they had never heard of PVM, they would not perceive any flicker.

[koboyedi]

Deal

[JSWolf]

Originally Posted by koboyedi

Deal

Thank you. It will be good to have some hard data.

[DNSB]

Originally Posted by JSWolf

Have you used a Forma and gotten eye strain? What I want to know is PVM a real problem or is a big deal being made by what some perceive as a problem that's really not a problem.

I haven't noted eyestrain from reading on my Forma nor have I noticed flickering. Given that the Forma uses a 1kHz cycle and even in saccade, no one has reliably claimed to be able to notice flicker with the naked eye when a >400Hz rate was used, I'm not worried about PWM being a problem.

[Maritimer555]

Hi All,
I picked up the Forma at Coles before Christmas. I have been reading on it everyday since mid Dec. my previous reader was the Aura One. I have noticed zero screen flickering issue nor have I noticed any eye strain vs the Aura One.

[JSWolf]

Originally Posted by DNSB

I haven't noted eyestrain from reading on my Forma nor have I noticed flickering. Given that the Forma uses a 1kHz cycle and even in saccade, no one has reliably claimed to be able to notice flicker with the naked eye when a >400Hz rate was used, I'm not worried about PWM being a problem.

Originally Posted by Maritimer555

Hi All,
I picked up the Forma at Coles before Christmas. I have been reading on it everyday since mid Dec. my previous reader was the Aura One. I have noticed zero screen flickering issue nor have I noticed any eye strain vs the Aura One.

Thank you both for hard data.

[NiLuJe]

FWIW, I'm sitting in front of a (rather large, 32") monitor with a rather "scary" barely above 300Hz PWM frequency, and I'm still alive.

And, no, I don't notice it with the naked (well, myopic & astigmatic ;p) eye. It's readily visible through any half-decent phone camera, as it is on the Forma. Where it also doesn't bother me one bit.

(And neither did I just after switching from my old, no PWM monitor).

[davidfor]

Originally Posted by NiLuJe

FWIW, I'm sitting in front of a (rather large, 32") monitor with a rather "scary" barely above 300Hz PWM frequency, and I'm still alive.

And, no, I don't notice it with the naked (well, myopic & astigmatic ;p) eye. It's readily visible through any half-decent phone camera, as it is on the Forma. Where it also doesn't bother me one bit.

(And neither did I just after switching from my old, no PWM monitor).

My wife suffers from severe and frequent migraines. And has some other eye issues. Flashing can trigger her migraines. If anyone was going to be affected by this, I would expect she would. But, she has been has been using the Forma for the last year or so without any issues.