Page 1 of 1

Pull-down, judder, film modes? Do they impact monitors?

Posted: 28 Jan 2019, 04:37
by MonarchX
I have a TV that does "True 48Hz" with "2:2 pull-down" and on white backgrounds I can see a bit of flicker in that mode. It appears that refresh rate MODES aren't necessarily refresh RATES..? That same TV allows turning that 48Hz mode on and off, so I have options:
1. 48Hz mode off (in TV settings) with 23/24Hz refresh rate selected in NVidia CP = no flickering, but worse motion (judder)
2. 48Hz mode on (in TV settings) with 23/24Hz refresh rate selected in NVidia CP = slight flickering, but smoother motion (no judder)

Newer TV's have similar film modes without flickering due to 3:3 (72hz) and 4:4 (96hz) pull-down. So... without those film modes, 23/24Hz refresh rate selected in NVidia CP is not actually true 23/24Hz..? It's still 60Hz... or at least still in 60Hz MODE..? CONFUSING!

Does any of that affect monitors? G-Sync? Free-Sync? Are 144Hz, 165Hz, and 240Hz refresh rates actually refresh rate modes or refresh rates within 60Hz mode and 3:2 pull-down?

Re: Pull-down, judder, film modes? Do they impact monitors?

Posted: 28 Jan 2019, 22:40
by Chief Blur Buster
MonarchX wrote:I have a TV that does "True 48Hz" with "2:2 pull-down" and on white backgrounds I can see a bit of flicker in that mode. It appears that refresh rate MODES aren't necessarily refresh RATES..? That same TV allows turning that 48Hz mode on and off, so I have options:
1. 48Hz mode off (in TV settings) with 23/24Hz refresh rate selected in NVidia CP = no flickering, but worse motion (judder)
2. 48Hz mode on (in TV settings) with 23/24Hz refresh rate selected in NVidia CP = slight flickering, but smoother motion (no judder)
Let me guess: It's a plasma TV?

Plasmas are always in permanent strobed mode; it's unavoidable. So use strobe-backlight motion blur mathematics (Blur Busters Law) when calculating motion blur on a plasma TV. That said, allow ~2-3ms persistence due to plasma phosphor. Most impulse-driven displays flicker at 60Hz or 120Hz. Switching it to 48Hz forced the flicker to go 48Hz or 96Hz.

If your TV is an LCD, then the strobe frequency changed, e.g. a backlight strobe reduced. (e.g. 120Hz->96Hz strobe as an example, or 60Hz->48Hz strobe).
MonarchX wrote:Newer TV's have similar film modes without flickering due to 3:3 (72hz) and 4:4 (96hz) pull-down. So... without those film modes, 23/24Hz refresh rate selected in NVidia CP is not actually true 23/24Hz..? It's still 60Hz... or at least still in 60Hz MODE..? CONFUSING!
48Hz doesn't necessarily flicker, especially on a sample-and-hold display.
MonarchX wrote:Does any of that affect monitors? G-Sync? Free-Sync? Are 144Hz, 165Hz, and 240Hz refresh rates actually refresh rate modes or refresh rates within 60Hz mode and 3:2 pull-down?
No, the flicker is probably because your TV is impulse-based. Plasma televisions are.
LCD panels are not (unless they use a strobe backlight mode) -- at which case, your TV is using some form of black frame insertion mode of some sort.

To explain better, there's a good article at Blur Busters Law And The Amazing Journey To Future 1000Hz Monitors which explains the flicker mathematics, stutter mathematics, and motion blur mathematics, in a universally generalized way. The math in the article is the same at 20Hz, 70Hz, 100Hz, 2000Hz, 5Hz or whatever -- so it's a useful read.

On my gaming monitor, I can do 48Hz 2:2 pulldown with no flicker. It just simply looks like ordinary perfect framepaced 48fps on a VRR monitor.

Re: Pull-down, judder, film modes? Do they impact monitors?

Posted: 01 Feb 2019, 21:49
by MonarchX
Thanks, but no, LCD displays also have these Film Modes. I'll inquire further on other forums and if I get a good answer, will reply here.

Re: Pull-down, judder, film modes? Do they impact monitors?

Posted: 02 Feb 2019, 03:06
by RealNC
I'm still not sure what it is you're asking. :P