AMOLED scrreen flicker?

[rkw]

Here is what I just found:


I had no idea that AMOLED screens had flicker. I wonder if some people actually perceive it while using devices where it is so apparent. And yes I know there is a relationship of the video capture rate making this look far, far worse than in real life. I have seen and handled the Samsung Note II and it's got a most excellent display and I could not see the flicker with my nekkid eye. But here the camera sees all.

[Teknikal]

http://www.howstuffworks.com/question336.htm

[rkw]

Originally Posted by Teknikal

http://www.howstuffworks.com/question336.htm

Thanks but I know how it works and why we are seeing it here. It is what was called in the film era "the strobe effect".

Your link applies to CRT displays not LCD displays. They just refresh differently which is why we started using them a couple decades ago as an effort to combat eye strain issues, well at least that was one reason...less worker's comp claims. I do seem to remember some early LCD monitors claimed less eye strain due to high refresh rates. And LCD's do refresh but just in a different manner as compared to a scanning CRT which is what stood out to me in the video, that characteristic rolling flicker.

I always understood LCD's sort of blink really-really fast and do not scan because the backlight provides the light and the pixels are adjusted independently. The rolling flicker was due to that scanning refresh.

Maybe what that really shows seeing is AMOLED panels actually have quite a slow refresh rate whatever the method. Maybe making them less than ideal for those who had problems with the old CRT monitors.

I seriously doubt anyone would visually notice the refresh cycling. Yet it's possible it may have an effect on some.

[5thWiggle]

I've only caught flickering a couple of times under very specific conditions on my original Galaxy Note. Light background on the screen, low screen brightness and under fluorescent lights with old style electromagnetic ballasts. I knew that AMOLED screens controled the brightness by pulse width modulation, but had originally thought that they were pulsing the entire screen as a block and was a little suprised to see the "raster" effect (after some thought, I realised that pulsing the entire screen could lead to some pixels not lighting at all in certain timing scenarios).

[Teknikal]

Originally Posted by rkw

Thanks but I know how it works and why we are seeing it here. It is what was called in the film era "the strobe effect".

Your link applies to CRT displays not LCD displays. They just refresh differently which is why we started using them a couple decades ago as an effort to combat eye strain issues, well at least that was one reason...less worker's comp claims. I do seem to remember some early LCD monitors claimed less eye strain due to high refresh rates. And LCD's do refresh but just in a different manner as compared to a scanning CRT which is what stood out to me in the video, that characteristic rolling flicker.

I always understood LCD's sort of blink really-really fast and do not scan because the backlight provides the light and the pixels are adjusted independently. The rolling flicker was due to that scanning refresh.

Maybe what that really shows seeing is AMOLED panels actually have quite a slow refresh rate whatever the method. Maybe making them less than ideal for those who had problems with the old CRT monitors.

I seriously doubt anyone would visually notice the refresh cycling. Yet it's possible it may have an effect on some.

Regardless the flicker is caused by the high shutter speed of the camera and not the amoled screen you will get the same result trying to film almost anything including crt's, lCD's, projector screens. sometimes the framerates just clash.

All screens with the exception of e-ink refresh constantly or they would be static pictures not screens.

[Purple Lady]

Originally Posted by Teknikal

Regardless the flicker is caused by the high shutter speed of the camera and not the amoled screen you will get the same result trying to film almost anything including crt's, lCD's, projector screens. sometimes the framerates just clash.

All screens with the exception of e-ink refresh constantly or they would be static pictures not screens.

But the video was of two different screens and only the AMOLED was flickering.

[rkw]

Originally Posted by 5thWiggle

I've only caught flickering a couple of times under very specific conditions on my original Galaxy Note. Light background on the screen, low screen brightness and under fluorescent lights with old style electromagnetic ballasts. I knew that AMOLED screens controled the brightness by pulse width modulation, but had originally thought that they were pulsing the entire screen as a block and was a little suprised to see the "raster" effect (after some thought, I realised that pulsing the entire screen could lead to some pixels not lighting at all in certain timing scenarios).

Sure that seems to make sense. Thanks for the tip. I was not certain how the AMOLED panels handled it.