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Does ELMB hurts eyes compare to CRT panel? Special glasses for that?

Posted: 13 Apr 2020, 13:40
by forii
Hello,

I have been always using flicker free panels, my previous one was 144Hz TN, but know I do have 240 HZ with ELMB (sync) - of course I do not use any feature of v-sync but I do use ELMB which I believe may hurt the eyes, is it really a true??

Is it save to use it? Or should I avoid that feature? i play better with it, but I would like to live longer or do not hurt my eyes.

I wear glasses (prescription glasses) but with standard protective filter like all glasses, it isn't special filter for gamers.

Does ELMB really hurt eyes even if I wear glasses? or should i buy special glasses for that?

Is it same like CRT monitor? or it is worse for the eyes?

I believe this feature is really worth to use

https://edgeup.asus.com/2019/tuf-gaming ... -monitors/

I have VG259QM Asus TUF

ALso, what about using Blue Light Filter with ELMB inside OSD? Is it the same like blue light filter in Windows 10?

Re: Does ELMB hurts eyes compare to CRT panel? Special glasses for that?

Posted: 13 Apr 2020, 17:30
by nuninho1980
forii wrote:
13 Apr 2020, 13:40
ALso, what about using Blue Light Filter with ELMB inside OSD?
Yes, you increase much the blue light filter inside OSD.
LED backlight with blue light is much more dangerous than flicker for eyes.

You enable ELMB but ELMB doesn't support below 85Hz. But below ~70Hz may affect eyes. ;)

But the conventional (cold cathode fluorescent) backlight doesn't affect eyes and this backlight is more conformable than CRT. ;)

Re: Does ELMB hurts eyes compare to CRT panel? Special glasses for that?

Posted: 13 Apr 2020, 18:02
by Chief Blur Buster
Short answer: It depends. Strobing does not bother everybody. Some of us get no eyestrain from a good-quality strobe backlight. Just make sure you have fps=Hz with strobe backlights if you want best strobing quality.

Long answer: I'll repost what I wrote in the other thread.

Also, refresh rate headroom can help, e.g. 144Hz strobe mode on a 240Hz panel can have less strobe crosstalk than 144Hz strobe mode on a 144Hz panel, or 240Hz strobe mode on a 240Hz panel. The extra refresh rate headroom can be reused as extra pixel-transition-time settlement period between refresh cycles (GtG hidden in VBI). However, 240fps at 240Hz strobing is lower latency, if lower strobe latency is more important than low strobe crosstalk.

______________

Everybody is different.

-- Some people are blur sensitive
-- Some people are flicker sensitive
-- Some people are blue-light sensitive
-- Some people are bright-light sensitive
-- Some people are motion sensitive
-- Some people are artifact-sensitive (i.e. nausea from artifacts -- ghosting/corona etc)
-- Some people have more eyestrain from motion blur, than from strobe-backlight flicker

Occasionally, even high-Hz flicker can be a red herring for sensitivity to other artifacts. Some people get eyestrain from PWM-dimming but not from strobed VSYNC ON (fps=Hz). This is because the PWM duplicate-image artifacts are like a serrated knife to human eyes. So while some headaches are flicker-related -- other humans with headaches from PWM dimming isn't from the flicker itself but from the artifacts generated by the PWM dimming flicker. Strobing is a refresh-rate synchronized flicker that is ideally one flash per frame. This results in beautiful motion with a low-strobe-crosstalk blur reduction mode at frame rates matching refresh rates. Other times, all kinds of flicker create eyestrain / headaches for a human and you're stuck with non-strobed.

TL;DR: Eyestrain from flicker has more variables than you expect
There are some people who have no direct eyestrian from flicker, but strain from the artifacts.

Example unfixable artifact from PWM dimming:
Image

Strobed fps=Hz can fix this:
Image

- Some people can't tolerate flicker at all; but
- Some people simply can't tolerate the artifacts from "non fps=Hz" flicker.

Unless you're motion-blur sensitive, then you need an incredibly high nonstrobed frame rate and refresh rate (240fps at 240Hz+) as the blur reduction method, to compensate for flicker sensitivity and blur sensitivity. That's partially why we're big fans of future 1000 Hz displays as strobeless motion blur reduction.

_________

ELMB can be turned on/off. Motion blur reduction modes are typically an optional mode or can be overriden. You get more motion blur, but the flickering stop. But again, everybody is different.

Re: Does ELMB hurts eyes compare to CRT panel? Special glasses for that?

Posted: 14 Apr 2020, 15:45
by forii
So is it ok to run ELMB with g-sync? but without v-sync?

G-sync doesnt give any input lag I heard, it can even low the input lag by itself (dunno thats correct?)

ELMB gives slight input lag but you have clear motion blur.

Re: Does ELMB hurts eyes compare to CRT panel? Special glasses for that?

Posted: 14 Apr 2020, 15:54
by Chief Blur Buster
forii wrote:
14 Apr 2020, 15:45
So is it ok to run ELMB with g-sync? but without v-sync?
The backup sync technology only activates for frame rates trying to equal or exceed maximum Hz. If you cap your frame rate, the fallback sync technology (VSYNC ON or VSYNC OFF) does not activate. So "G-SYNC + VSYNC ON" and "G-SYNC + VSYNC OFF" looks identical if frametimes are always permanently within the monitor's refresh rate range. However, that does not always happen, since frame rate caps are not perfect.

The bottom line is that the combining you hear about (G-SYNC + VSYNC ON) versus (G-SYNC + VSYNC OFF) is that it always only uses G-SYNC when framerates are within the VRR range. And the fallback sync technology (VSYNC ON or VSYNC OFF) activates only if your framerates reaches max Hz (or beyond).

Frame rate capping solves that problem, avoiding the disadvantages of the fallback sync technology (such as lag or tearing).
forii wrote:
14 Apr 2020, 15:45
G-sync doesnt give any input lag I heard, it can even low the input lag by itself (dunno thats correct?)
Definitely G-SYNC has much lower lag than VSYNC ON. Basically G-SYNC can give you a permanent "VSYNC ON looking experience" without the latency of VSYNC ON.
forii wrote:
14 Apr 2020, 15:45
ELMB gives slight input lag but you have clear motion blur.
ELMB-SYNC with a frame rate cap, has less lag than ELMB + VSYNC ON. So if you want the beautiful fps=Hz ELMB, with ELMB-SYNC, without the artifacts of varying ELMB-SYNC framerates, you'll want to cap your ELMB framerates near max Hz.

There are some artifacts with ELMB-SYNC, but ELMB-SYNC is still useful for reducing strobe lag, provided you run fps=Hz near the capped frame rate near max Hz -- the ELMB frame rates without latency and without crosstalk artifacts.
____

Be careful about your flicker sensitivity though -- if a 100Hz CRT still hurt your eyes, a motion blur reduction mode might. Fortunately, strobing at >100Hz is usually okay for most eyes. Just avoid the other causes of eyestrain (poor colors, crosstalk, double images) by choosing a high quality strobe backlight and doing fps=Hz.

Re: Does ELMB hurts eyes compare to CRT panel? Special glasses for that?

Posted: 14 Apr 2020, 16:05
by forii
@Chief Blur Busters

1) Alright, but why would someone use extra v-sync (with g-sync!!) if it does not active due to -3fps cap? + g-sync already give the pernament "v-sync experience)
is the v-sync actually working or not if it doesnt reach the equal fps of hz or above?

And if so, why it gives some input lag if it isn't active like you said due to 3-fps bellow 240hz.

2)You said elmb with g-sync with frame rate cap has less lag than elmb + vsync on, that's correct (even if you said that v-sync doesnt active if fps are not above Hz of monitor).

3) What about ELMB-sync vs ELMB? Because I heard g-sync doesnt give any input lag, or it actually does?

4)And... how does it work with 240hz, because I believe that does matter a lot, we are not talking about input lag of 60hz or even 144hz monitor, we talking here of 240Hz monitor with quite low input lag by itself (Asus VG259QM)

Re: Does ELMB hurts eyes compare to CRT panel? Special glasses for that?

Posted: 14 Apr 2020, 16:22
by Chief Blur Buster
forii wrote:
14 Apr 2020, 16:05
1) Alright, but why would someone use extra v-sync (with g-sync!!) if it does not active due to -3fps cap? + g-sync already give the pernament "v-sync experience)
is the v-sync actually working or not if it doesnt reach the equal fps of hz or above?
Even if you choose a frame rate cap, you still have to choose a fallback sync technology. By default, the fallback sync tech is VSYNC ON.

Caps are often aiming at averages. Capping is not always accurate.

A 141fps cap may create some frames that are 1/130sec and other frames 1/150sec. One of those frames gets the G-SYNC treatment, and the other frame gets the fallback sync technology (latency for that specific frame, or tearing for that specific frame).

A bigger differential means capping imperfections will occur less often.
A more accurate frame rate cap means capping imperfections will occur less often.

Depending on the game, the cap accuracy, and the capping differential --sometimes it will happen only instantaneously once every few seconds. Other times, it will happen continuously. Remember, for 200fps, there are potentially up to 200 different sync-technology treatments per second. If all frametimes are all within VRR range, then all of them got all the G-SYNC treatment. That's assuming all frametimes were permanently within the VRR range.

Please note: There is sometimes a pick-poison choice. In-game framerate caps are less accurate but have less lag. While RTSS frame rate caps sometimes have more lag than in-game frame rate caps, but is more accurate. Sometimes prioritization becomes necessary -- deciding which frame rate capper to use is a strategic move that often depends on the game and on the priorities you have. For VRR capping, however, it's usually better to use the lower-lag frame rate cap.

The more imperfect a frame rate cap is, the more often the frametimes will deviate to a frametime faster than a refresh cycle. That's why the common "cap a few below" advice for VRR. For very perfect frame pacing (e.g. RTSS and emulators), it is possible to use tighter cap (0.5fps or 1.0fps below). For very imperfect in-game framerate caps, it is possible to cap about 10fps below and still occasionally get fallback sync treatment (rare tearing or rare millisecond-lagged frames)
forii wrote:
14 Apr 2020, 16:05
And if so, why it gives some input lag if it isn't active like you said due to 3-fps bellow 240hz.
VSYNC OFF does the equivalent of real-time mid-raster splicing of frame slices, which means that frame rates higher than refresh rates, can sometimes have multiple frameslices per refresh cycle. This can bypass part of scanout latency. For more information, see High Speed Videos of Scanout and Advantages of Frame Rates Above Refresh Rates.

If pushed to the limit, VSYNC OFF ultra-high-framerates can become a scant 1-2ms lower lag than properly capped 240Hz G-SYNC. As long as you keep your refresh rate high, 240Hz G-SYNC has a worst-case scanout latency of 1/240sec ~= 4.1ms, and 360HGz G-SYNC has a worst-case scanout latency of 1/360sec ~= 2.7ms

The bottom line is the 3fps cap differential is the most common parrot advice becase it has worked so well for so many people. (See Capping Differentials FAQ for some complex reading on this).

The right tool for the right job -- for example for games running frame rates far beyond refresh rates (e.g. CS:GO) may favour ultra-high-framerate VSYNC OFF for best scores, while other games running frame rates within VRR range (e.g. PUBG) may benefit far more from G-SYNC.

We are big proponents of "Right Tool For The Right Job".
forii wrote:
14 Apr 2020, 16:05
2)You said elmb with g-sync with frame rate cap has less lag than elmb + vsync on, that's correct (even if you said that v-sync doesnt active if fps are not above Hz of monitor).
That's right. Capped G-SYNC looks visually identical to VSYNC ON, but with less lag than VSYNC ON. Good caps looks just like perfect fps=Hz.
forii wrote:
14 Apr 2020, 16:05
3) What about ELMB-sync vs ELMB? Because I heard g-sync doesnt give any input lag, or it actually does?
forii wrote:
14 Apr 2020, 16:05
4)And... how does it work with 240hz, because I believe that does matter a lot, we are not talking about input lag of 60hz or even 144hz monitor, we talking here of 240Hz monitor with quite low input lag by itself (Asus VG259QM)
See read my reply in the other thread

For 240Hz, scanout latency is very low. (Scanout latency is because not all pixels on a monitor refresh simultaneously).

Sometimes questions creating unnecessarily complex decision. The moral of the story is, Right Tool For Right Job -- especially if you earn money playing competitive games. For games that are running frame rates that are massively permanently beyond Hz (CS:GO is a common game) sometimes ultra-high-capped VSYNC OFF is the favourite tool of choice, for people where 1ms-2ms is actually important.

Let's cut to the chase. If you earn (1) championship money in esports, and (2) you only play CS:GO, and (3) monitors don't exist yet that capture the entire CS:GO frame rate range (e.g. 1000Hz monitor), then (4) It's often difficult to beat VSYNC OFF in competitive advantage. Most CS:GO pros use this.

Now.... CS:GO is not the only game ever invented. If you are trying to play games that that have framerates always within the G-SYNC range -- it can be a competitive advantage to use G-SYNC with the right settings. Different games benefit more from G-SYNC than others. The visual advantage of G-SYNC (no stutters, no tearing) is good for some unoptimized engines (Example: PUBG), and the blur advantage of motion blur reduction (ELMB, ULMB, etc) is useful for very scrolly/panny/spinny games without crosshairs (Example: Rocket League).

There are some hidden competitive advantages lurking for non-CS:GO games in certain display technlogies. Some players (who play multiple games) use dramatically different settings for different games.