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Re: Pi power

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On 07/01/2021 07:40, Ahem A Rivet's Shot wrote:
> 	No, but 50Hz interlaced monitors (stripped TVs really) are and
> removing the interlace was considered enough to make it flicker free and
> "professional" circa 1980 - I sometimes turned the interlace back on and
> pushed the resolution up. In more recent times 60Hz was said to be needed
> for flicker free and now it's 70Hz I'm seeing and high end TVs are currently
> advertising 120Hz.

Several different issues there.

Old CRT TVs worked with an interlaced signal so needed long persistence 
phosphors so the each field of alternating scan lines would still be 
visible when the next field was displayed. UK PAL TVs were set up for 
50Hz fields so had a longer persistence than US NTSC at 60Hz.

CRT monitors (generally) worked with non interlaced signals, so had low 
persistence phosphors as all the scan lines would be updated every 
frame. Monitors were invariably designed for the US market so had 
phosphor persistence for a minimum of 60Hz frame rate, and would look 
terrible if driven at 50Hz.

As monitor resolutions and sizes increased the frame rates also 
increased to 70Hz or 75Hz, to reduce flicker and smearing of screen updates.

Now with LCD, LCD/LED and OLED technologies the screen does not flicker 
at the update rate. Panels used to have a 60Hz update rate to match US 
content (but would be fine for 50Hz), but active 3D drove the adoption 
of 120Hz or greater panels, so alternate views could be shown at 60Hz. 
3D has largely been dropped now, but 120Hz or greater panels still 
exist, so they can either be driven at a higher frame rate by games 
consoles, or additional intermediate frames are generated for lower 
refresh rate content, in both cases to make animation smoother.

---druck

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Pi power Tim Streater <timstreater@greenbee.net> - 2021-01-05 22:54 +0000
  Re: Pi power Andy Burns <usenet@andyburns.uk> - 2021-01-05 23:16 +0000
    Re: Pi power "Mayayana" <mayayana@invalid.nospam> - 2021-01-05 19:59 -0500
      Re: Pi power A. Dumas <alexandre@dumas.fr.invalid> - 2021-01-06 07:31 +0000
        Re: Pi power "Mayayana" <mayayana@invalid.nospam> - 2021-01-06 08:18 -0500
        Re: Pi power jornws200602@xs4all.nl (Oscar) - 2021-01-06 14:02 +0000
    Re: Pi power mjb@signal11.invalid (Mike) - 2021-01-06 09:44 +0000
      Re: Pi power Martin Gregorie <martin@mydomain.invalid> - 2021-01-06 10:31 +0000
        Re: Pi power Tim Streater <timstreater@greenbee.net> - 2021-01-06 10:44 +0000
          Re: Pi power Joe <joe@jretrading.com> - 2021-01-06 11:03 +0000
      Re: Pi power Tim Streater <timstreater@greenbee.net> - 2021-01-06 10:32 +0000
        Re: Pi power Andy Burns <usenet@andyburns.uk> - 2021-01-06 10:57 +0000
          Re: Pi power TimS <timstreater@greenbee.net> - 2021-01-06 11:44 +0000
            Re: Pi power Andy Burns <usenet@andyburns.uk> - 2021-01-06 12:10 +0000
              Re: Pi power TimS <timstreater@greenbee.net> - 2021-01-06 13:25 +0000
                Re: Pi power Andy Burns <usenet@andyburns.uk> - 2021-01-06 14:41 +0000
                Re: Pi power TimS <timstreater@greenbee.net> - 2021-01-06 15:17 +0000
                Re: Pi power Martin Gregorie <martin@mydomain.invalid> - 2021-01-06 16:05 +0000
                Re: Pi power TimS <timstreater@greenbee.net> - 2021-01-06 16:14 +0000
        Re: Pi power A. Dumas <alexandre@dumas.fr.invalid> - 2021-01-06 12:02 +0000
      Re: Pi power Andy Burns <usenet@andyburns.uk> - 2021-01-06 10:55 +0000
        Re: Pi power Chris Green <cl@isbd.net> - 2021-01-06 11:19 +0000
          Re: Pi power Axel Berger <Spam@Berger-Odenthal.De> - 2021-01-06 13:13 +0100
            Re: Pi power Ahem A Rivet's Shot <steveo@eircom.net> - 2021-01-06 12:47 +0000
              Re: Pi power Joe <joe@jretrading.com> - 2021-01-06 20:20 +0000
                Re: Pi power druck <news@druck.org.uk> - 2021-01-06 20:43 +0000
              Re: Pi power Eli the Bearded <*@eli.users.panix.com> - 2021-01-06 23:08 +0000
                Re: Pi power Ahem A Rivet's Shot <steveo@eircom.net> - 2021-01-07 07:40 +0000
                Re: Pi power Axel Berger <Spam@Berger-Odenthal.De> - 2021-01-07 09:08 +0100
                Re: Pi power John Aldridge <jpsa@cantab.net> - 2021-01-07 09:20 +0000
                Re: Pi power The Natural Philosopher <tnp@invalid.invalid> - 2021-01-07 08:16 +0000
                Re: Pi power druck <news@druck.org.uk> - 2021-01-07 09:53 +0000
                Re: Pi power Martin Gregorie <martin@mydomain.invalid> - 2021-01-07 12:40 +0000
                Re: Pi power Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2021-01-07 19:29 +0000
                Re: Pi power David Higton <dave@davehigton.me.uk> - 2021-01-07 21:05 +0000
          Re: Pi power Ahem A Rivet's Shot <steveo@eircom.net> - 2021-01-06 12:39 +0000
            Re: Pi power Chris Green <cl@isbd.net> - 2021-01-06 17:04 +0000
              Re: Pi power Theo <theom+news@chiark.greenend.org.uk> - 2021-01-06 18:02 +0000
          Re: Pi power Theo <theom+news@chiark.greenend.org.uk> - 2021-01-06 16:41 +0000
            Re: Pi power Martin Gregorie <martin@mydomain.invalid> - 2021-01-06 17:04 +0000
              Re: Pi power druck <news@druck.org.uk> - 2021-01-06 18:50 +0000
                Re: Pi power Martin Gregorie <martin@mydomain.invalid> - 2021-01-06 20:39 +0000
            Re: Pi power TimS <timstreater@greenbee.net> - 2021-01-06 18:58 +0000
  Re: Pi power Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2021-01-08 22:33 -0500
    Re: Pi power Anssi Saari <as@sci.fi> - 2021-01-09 12:03 +0200

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