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Comment by porphyra | Hacker News Reader

I wonder why? With CRTs there is noticeable flickering but no such issue happens with OLEDs. Is it just the contrast ratio?

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Regarding CRT flicker: for monitors, you don't want to drive a CRT below 90Hz (120 Hz is pretty stable), even TVs were at the end 100Hz (refreshing frames multiple times). The problem was "cost effective" office PCs with graphics hardware just capable of 60Hz refresh, which isn't a great idea, unless you have a monochrome monitor with slow phosphor. (Meaning, this was just an abuse of technology – and workers.)

> even TVs were at the end 100Hz (refreshing frames multiple times)

Maybe in Europe? But 100Hz is a terrible thing to do with 60Hz signals. Possibly US bound HD CRT TVs did 120Hz? But I don't recall hearing about those ever.

Yes, my experience was definitively European, as in PAL. It was rather neat, until the image panned… (The problem being, apparently you still have to alternate between fields in order to maintain the illusion of interlaced video, so you get an A-B-A-B C-D–C-D… sequence. Some attempts were made to improve the resulting interlace clash by comb filters, etc, but this only started to work somewhat properly, when the days of CRTs were already numbered.) I actually don't know if there were similar developments with 60Hz standards.

Not entirely sure but I think OLED pixels modulate brightness with PWM, which causes high frequency (though invisible) flickering.

LCDs have PWM-dimmed backlights, so if your laptop isn't set to maximum brightness, you're probably staring at a flickering surface too.

Perhaps a simpler explanation is just contrast? Both OLEDs and CRTs can produce much higher contrast than LCDs.

No PWM is common for LCDs https://www.notebookcheck.net/PWM-Ranking-Notebooks-Smartpho...

The PWM frequency is typically much higher for LCDs than OLEDs, if it is used, and much less likely to be a problem.

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