How to Fix Ghosting/Double Image When Displaying 30 FPS on 165 HZ display?

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BeansInbread
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How to Fix Ghosting/Double Image When Displaying 30 FPS on 165 HZ display?

Post by BeansInbread » 07 Aug 2024, 03:05

Hello,
I’ve been dealing with an issue on my 165 hz monitor where there is visible double images that produce a juddering effect on moving objects in games and videos that are in a low FPS. I was playing Deltarune (2D game locked to 30 FPS) and this effect was very noticeable the entire time. The effect is not noticeable on other games, it only is noticeable in panning shots in videos or in 2d games with locked fps.

G-sync, Blur reduction, AMA/overdrive, have not helped. Changing my refresh rate in windows from 165 to 60 hz and 30 hz also did not work. I contacted customer support and they said nothing is wrong with my monitor. Model is benqex2510s. If anyone has any advice I’d greatly appreciate it.

chocobeau
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Re: How to Fix Ghosting/Double Image When Displaying 30 FPS on 165 HZ display?

Post by chocobeau » 09 Aug 2024, 05:29

You can try "lossless scaling" software from steam it has an option go doubling or tripling frames and soon x4 (with some artifacts).
So for example 30fps to 60@60hz you shouldn't see double image just a bit of blur because of the low refresh rate.

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Re: How to Fix Ghosting/Double Image When Displaying 30 FPS on 165 HZ display?

Post by RealNC » 09 Aug 2024, 10:08

BeansInbread wrote:
07 Aug 2024, 03:05
I’ve been dealing with an issue on my 165 hz monitor where there is visible double images that produce a juddering effect on moving objects in games and videos that are in a low FPS.
Does the monitor have some motion blur reduction mode (strobing) that you turned on? If yes, turn it off for low FPS content.
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Re: How to Fix Ghosting/Double Image When Displaying 30 FPS on 165 HZ display?

Post by Chief Blur Buster » 13 Aug 2024, 11:07

Also, the other stone (if not using strobing):

If it's the stroboscopic effect / phantom array effect, low frame rates amplify this.
The Stroboscopic Effect of Finite Frame Rates.

Sometimes people call this the double-image effect, as yet another kind of double-image effect different from double-strobe.
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Re: How to Fix Ghosting/Double Image When Displaying 30 FPS on 165 HZ display?

Post by xenphor » 17 Aug 2024, 18:55

In a Digital Foundry video, Alex explains that using LFC with a high refresh rate monitor will suffer from the double image effect. So, when playing a game that is locked to 60hz, is it better to set the monitor to 60hz and use VRR that way?

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Re: How to Fix Ghosting/Double Image When Displaying 30 FPS on 165 HZ display?

Post by RealNC » 17 Aug 2024, 20:29

xenphor wrote:
17 Aug 2024, 18:55
In a Digital Foundry video, Alex explains that using LFC with a high refresh rate monitor will suffer from the double image effect. So, when playing a game that is locked to 60hz, is it better to set the monitor to 60hz and use VRR that way?
Well, he is wrong. LFC cannot induce any double-image effect nor increase motion blur. At 30FPS for example, LFC will drive the display at 60Hz and scan out the frame twice. Without LFC, the display would run at 144Hz (on a 144Hz display) and the frame would be scanned out 4 times, not just two. On a 240Hz display without LFC, the same frame would get scanned out 8 times instead of 2.

So Alex contradicts his own logic here :-/ The claim that scanning out the same frame more than once creates more blur or a multiple image effect is wrong to begin with, but even if we assume it's true, the logic itself doesn't check out, because then, LFC would decrease motion blur or multiple image effect, not make it worse.
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Re: How to Fix Ghosting/Double Image When Displaying 30 FPS on 165 HZ display?

Post by xenphor » 17 Aug 2024, 21:11

RealNC wrote:
17 Aug 2024, 20:29
Well, he is wrong. LFC cannot induce any double-image effect nor increase motion blur. At 30FPS for example, LFC will drive the display at 60Hz and scan out the frame twice. Without LFC, the display would run at 144Hz (on a 144Hz display) and the frame would be scanned out 4 times, not just two. On a 240Hz display without LFC, the same frame would get scanned out 8 times instead of 2.

So Alex contradicts his own logic here :-/ The claim that scanning out the same frame more than once creates more blur or a multiple image effect is wrong to begin with, but even if we assume it's true, the logic itself doesn't check out, because then, LFC would decrease motion blur or multiple image effect, not make it worse.
Okay, that's interesting. It's possible I misunderstood what he said. He starts talking about it at 13:48.

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Re: How to Fix Ghosting/Double Image When Displaying 30 FPS on 165 HZ display?

Post by LordPhotonboy » 18 Aug 2024, 17:55

xenphor wrote:
17 Aug 2024, 21:11
RealNC wrote:
17 Aug 2024, 20:29
Well, he is wrong. LFC cannot induce any double-image effect nor increase motion blur. At 30FPS for example, LFC will drive the display at 60Hz and scan out the frame twice. Without LFC, the display would run at 144Hz (on a 144Hz display) and the frame would be scanned out 4 times, not just two. On a 240Hz display without LFC, the same frame would get scanned out 8 times instead of 2.

So Alex contradicts his own logic here :-/ The claim that scanning out the same frame more than once creates more blur or a multiple image effect is wrong to begin with, but even if we assume it's true, the logic itself doesn't check out, because then, LFC would decrease motion blur or multiple image effect, not make it worse.
Okay, that's interesting. It's possible I misunderstood what he said. He starts talking about it at 13:48.
RealINC,
First of all, you said "playing a game that is locked to 60Hz"... did you mean 60FPS? If the game is 60FPS already, then a VRR screen just matches that at 60Hz.

48Hz is often chosen as the minimum refresh because any lower causes visual flickering. (If the screen refreshed instantly that wouldn't be an issue but it starts updating at the top down to the bottom similar to old CRT monitors). So 50FPS becomes 50Hz on the monitor. 47FPS becomes 94Hz on the monitor.

Xenphor,
Alex is 100% correct.
The answer is at the bottom of this page:
https://blurbusters.com/faq/motion-blur-reduction/

"These duplicate images are not strobe crosstalk. It is caused by multiple backlight strobe flashes per unique frame."

You're mostly right on the second part, but obviously 30 doesn't divide into 144 so you'd either have judder/stutter if VSYNC was engaged as you'd periodically have to hold some frames longer than others or you'd get screen tearing with VSYNC OFF since you start drawing the new frame at different parts of the screen refresh.

30/240 with each frame drawn 8x is correct.

240FPS->240Hz is super clear
30FPS->240Hz is not

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Re: How to Fix Ghosting/Double Image When Displaying 30 FPS on 165 HZ display?

Post by RealNC » 18 Aug 2024, 19:34

(Btw, your posts didn't appear because new users with less than 5 posts go through the anti-spam moderation queue. I believe this is mentioned in the message that appears when you post.)
LordPhotonboy wrote:
18 Aug 2024, 17:55
RealINC,
First of all, you said "playing a game that is locked to 60Hz"... did you mean 60FPS?
I didn't say that. xenphor said that, and I assume he meas 60FPS.
Xenphor,
Alex is 100% correct.
The answer is at the bottom of this page:
https://blurbusters.com/faq/motion-blur-reduction/
VRR and motion blur reduction are mutually exclusive. There's only a couple of monitors that support both at the same time. So when we're talking about VRR, I assume the MBR functionality is disabled.
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Re: How to Fix Ghosting/Double Image When Displaying 30 FPS on 165 HZ display?

Post by LordPhotonboy » 18 Aug 2024, 19:45

(sorry if there's a double post AND for mixing up the names. RealINC->Xenphor and vice versa)

RealINC
*I've literally given the link that explains the reason for the blurring. It's at the bottom of the page, called "Duplicate Images on Impulsed Displays" and it is exactly what Alex is referring to and it is a real thing.

I can understand WHY you think it's not true. But it is. And yes, this is ignoring Motion Blur Reduction.

I'm guessing GSync Pulsar will help address this issue.

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