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

[RealNC]

*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.

But Alex isn't referring to CRTs or plasmas. Those don't have VRR to begin with. He's obviously referring to LCDs and OLEDs, with VRR active, and that means those are NOT impulse-type displays. They are hold-type displays (aka sample-and-hold.)

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

No. Pulsar will make it possible to use VRR and MBR ("ULMB" as Nvidia brands it) at the same time to begin with. This will actually introduce the duplicate image problem, not solve it. That problem does not exist right now, because right now, g-sync and ULMB can not be used at the same time. Being able to use ULMB means the display will become impulsed. Right now, if you use g-sync, it is not impulsed.

Once g-sync pulsar arrives, THEN what Alex said will actually be relevant, except it will still be wrong, because LFC will reduce the multiple image effect, not increase it. As I said before, with LFC at an example FPS of 30, LFC will only scan out the frame twice even on a 240Hz display. That's a double-image effect. Without LFC, the frame will be scanned out 8 times, so that's way worse. You'll be seeing a trail of 8 images instead of just 2.

[LordPhotonboy]

FIXING the issue?
You can't really, barring a new GSync Pulsar display which is coming at some point.
https://www.nvidia.com/geforce/news/g-s ... g-monitor/

A lot of these issues aren't intuitively obvious. To back up, there are multiple reasons the moving screen information doesn't look correct. One reason is simple ghosting caused by pixels taking too long to change. A white circle on a black screen would have a slight trail in motion for example.

Another issue is image PERSISTANCE which is a problem in our eyes/brain when certain conditons are met. You fix or mitigate this issue by NOT showing an image every so often. This is why you would insert black frames (Black Frame Insertion) or strobe a backlight rather than continuously have a backlight on. Film projectors do this. Old ones just had a spinning disk that periodically blocked the light. (OLED has no backlight to pulse so it would use BFI. The LG CX had BFI but LG dropped it. Probably because implementing it along with VRR was difficult and/or there was insufficient brightness).

So...
NVidia Pulsar, for LCD displays, is going to have a variable backlight that changes along with the monitor refresh rate. You'd still have 30FPS-> 60Hz likely but adding in strobing should help fix the persistance issue. I'm honestly not sure how 30FPS-> 120Hz would be affected by a strobing backlight. It would be blurrier than 30FPS->60Hz with a static backlight, but add in the strobing and I'm not sure what changes.

TBC, if you had a monitor that supports ULMB (via backlight strobing) if you changed the monitor to 60Hz and gamed at 30FPS, with VRR/Freesync/GSync off but ULMB on then that scenario should be near identical to what NVidia is trying to do but obviously that's not ideal. (and NVidia would likely have other changes to optimize things. How many times does the backlight pulse per Hz? No idea.)

BUT...
There are other reasons why you get weird issues that seem similar to this. For example, I was playing SKYRIM (AE) at 60FPS and now 90FPS and going crazy as when panning I got this double image effect. But not always. I just figured out that if it occurs I can alt-tab out of the game, then alt-tab back and it's gone. What? No idea. The FPS and Hz are both 90. The camera pans smoothly. The only difference is the double-image. When it goes away it's mostly normal motion blur due to the pixels taking a bit too long to change.

Summary/TLDR:
You can't completely fix the issue. You can improve it by lowering the refresh of your monitor. Go to the Blurbusters link I gave and read how Hz/FPS ratio affects this. The higher the number the worse it gets.

There are multiple reasons. It gets confusing.

NVidia Pulsar likely will greatly improve this for LCD. I'm not sure if it's being worked on for OLED but the solution will be similar, but will involve turning off the pixels periodically.

Personally, I'm getting so pleased with 90FPS/90Hz gaming that I find it obvious to "only" play at 60FPS and 30FPS for me is annoying. Which sucks because I have a few 30FPS games I like.

(oddly, I started to notice the 30FPS/60Hz issue last year even though I'd played for over TEN YEARS on the same 1440p/60Hz (non-VRR) monitor. I almost wonder if watching my OLED TV broke my brain as that's the only thing that changed.)

[RealNC]

All of these things are known. The discussion was about LFC generating motion blur or adding a double-image effect. Which is not true. The former happens regardless of LFC, and the latter doesn't happen at all with VRR.

[LordPhotonboy]

UPDATE:
Pretty sure I made a mistake in the post I just sent. Ya, it's confusing.

30FPS->60Hz by manually changing the monitor refresh to 60Hz is unnecessary with a VRR/GSync/Freesync display as that will happen automatically anyway.

What I MEANT to say was to do that only if your monitor supports ULMB. Feel free to experiment, but I believe with VRR disabled 30FPS->60Hz with ULMB enabled is better than 30FPS if the monitor is at 144Hz+ in terms of visual clarity.

So in other words, for 30FPS games try:
GSync/Freesync OFF
ULMB ON
Monitor set to 60Hz

SORRY if I got that mixed up.

[LordPhotonboy]

All of these things are known. The discussion was about LFC generating motion blur or adding a double-image effect. Which is not true. The former happens regardless of LFC, and the latter doesn't happen at all with VRR.

You keep arguing this despite my giving you the link that proves you wrong.

It's literally as simple as a single FRAME being refreshed more than once. It's not directly related to VRR or LFC. VRR needs to be enabled for LFC to be on. LFC causes multiple, duplicate frames to be drawn... but the final issue is ONLY dependent on the same frame being drawn multiple times.

The fact that the screen is refreshing multiple times per frame is what matters. It does NOT matter how we get to this point.

There's no point in me arguing anymore. You either believe me, Alex from Digital Foundry and Blurbusters or you don't. I have no way to prove it to you.

[RealNC]

You keep arguing this despite my giving you the link that proves you wrong.

It's literally as simple as a single FRAME being refreshed more than once. It's not directly related to VRR or LFC. VRR needs to be enabled for LFC to be on. LFC causes multiple, duplicate frames to be drawn... but the final issue is ONLY dependent on the same frame being drawn multiple times.

The fact that the screen is refreshing multiple times per frame is what matters. It does NOT matter how we get to this point.

There's no point in me arguing anymore. You either believe me, Alex from Digital Foundry and Blurbusters or you don't. I have no way to prove it to you.

You failed to explain to me how not using LFC makes this better. DF's claim is that LFC will increase motion blur, because it causes the same frame to be scanned out twice. I say that this happens regardless of LFC. LFC does not make things worse. The frame is going to be scanned out multiple times regardless of LFC, and in fact it will be scanned out more times without LFC than with it.

You posted a link that has absolutely nothing to do with LFC or VRR. We already know that on impulse displays you get a multiple image effect if you show the same frame more than once. And? What does this have to with LFC making things worse? Why would LFC create a double-image effect that wouldn't be there without LFC? And how would even get a double-image effect with the display not even be impulsed?

DF's claim is not just wrong, but is wrong at two different levels.

I don't know what else to say either. It's simple logic you're just failing to grasp.

[BeansInbread]

UPDATE:
Pretty sure I made a mistake in the post I just sent. Ya, it's confusing.

30FPS->60Hz by manually changing the monitor refresh to 60Hz is unnecessary with a VRR/GSync/Freesync display as that will happen automatically anyway.

What I MEANT to say was to do that only if your monitor supports ULMB. Feel free to experiment, but I believe with VRR disabled 30FPS->60Hz with ULMB enabled is better than 30FPS if the monitor is at 144Hz+ in terms of visual clarity.

So in other words, for 30FPS games try:
GSync/Freesync OFF
ULMB ON
Monitor set to 60Hz

SORRY if I got that mixed up.

I don’t think that ULMB on my monitor can be enabled with a low hz value like 60hz, I think it has to be above 120 but I’m not sure the exact threshold. I’ve been trying other methods like setting my monitor to 60HZ and using rivatuner 1/2 scanline sync. I do appreciate the help though. Guess I’ll just have to just wait for g-sync pulsar? Though I’m still not sure why I don’t notice this on my TV or phone, watching videos panning shots stutter on my monitor but I’ve never seen that on another device. Effect not noticeable on games above 60FPS and 30FPS games are pretty rare so I can just put up with it I guess. Thanks everyone.