BenQ Zowie DyAC concern

[speancer]

Hi

I would like to ask you something about Dynamic Accuracy motion blur reduction technology from BenQ Zowie.

For a word of introduction: a few weeks ago I purchased a new display, Acer Predator XB271HU, it's an IPS panel with 165 Hz refresh rate and native G-SYNC support. Unfortunately, I am quite disappointed with this display. I found G-SYNC to be pretty much redundant (I don't really notice any difference in AAA games, and for my competitive play it's useless), also the display suffers from noticeable ghosting, even on Normal overdrive setting, while Extreme setting would produce insane overshoot error and inverse ghosting. Image is also still quite blurry in motion, I guess the response time is not that great here. Not to mention horrible backlight bleed on bottom right corner

I decided to try some other display to further improve my competitive play, I am a highly ranked former CS 1.6/CS:GO player. I want to give an extremely speedy display with 240 Hz refresh rate a go, such as BenQ Zowie XL2546, which also happens to have that DyAc thingy. From presentations I've seen, it drastically reduces blur and ghosting, that annoying trailing effect behind rapidly moving objects.

So, first of all, is there anyone who experienced/tested DyAc and can share some impressions? Is it worth it? Is it as good as some say? I've seen some very positive reviews on DyAc, but also some less enthusiastic opinions. XL2546 is a quite costly display for just a 1080p TN panel, especially comparing to XL2540 which is a lot cheaper, where the main difference between them is DyAc, so it is a concern.

Secondly, does DyAc work outside of monitor's refresh rate, so I won't have to enable any FPS cap (which is no good for CS:GO) ? On the other hand, is it affected by going below the refresh rate? Most of the time I will probably be around 200-400+ FPS in CS:GO, so is that any problem for this technology? I don't really know much about blur reduction technologies, so I'm asking away.

Lastly, I see that DyAc actually disables flicker-free function. Is that any concern? I don't think I've ever seen a display without flicker-free thing.

I will appreciate your help!

[Chief Blur Buster]

So, first of all, is there anyone who experienced/tested DyAc and can share some impressions? Is it worth it? Is it as good as some say? I've seen some very positive reviews on DyAc, but also some less enthusiastic opinions. XL2546 is a quite costly display for just a 1080p TN panel, especially comparing to XL2540 which is a lot cheaper, where the main difference between them is DyAc, so it is a concern.

If you want a motion blur reduction mode that doesn't degrade brightness, it's good.

I presume you already briefly tested the ULMB mode in the Acer Predator XB271HU before? (Switch to 120Hz, then enable ULMB in monitor menus, then view animations such as www.testufo.com/photo ...)

However, you notice that the brightness is a lot less. That doesn't happen with the XL2546 -- its motion blur reduction mode is practically equal in brightness whether you turn it on/off. That can be worth the cost premium for those who don't want a dim motion blur reduction mode.

On the other hand, is it affected by going below the refresh rate? Most of the time I will probably be around 200-400+ FPS in CS:GO, so is that any problem for this technology? I don't really know much about blur reduction technologies, so I'm asking away.

Motion blur reduction use a strobe backlight, as seen in high speed videos at www.blurbusters.com/lightboost/video
This allows them to behave more like CRTs/plasmas in terms of motion clarity -- less motion blurring.

Lastly, I see that DyAc actually disables flicker-free function. Is that any concern? I don't think I've ever seen a display without flicker-free thing.

A strobe backlight (flicker) is a method of motion blur reduction -- see Motion Blur Reduction FAQ. A CRT and plasma display naturally flickers thanks to its phosphor, and that was a defacto motion blur reduction back in the old days.

Both the XL2540 and XL2546 has a motion blur reduction mode. They both use a strobe backlight. What's different about XL2546 is that the motion blur reduction mode is brighter.

Ideally, use high mouse DPIs when using a motion blur reduction mode (1600dpi or higher) to reduce the amplified microstuttering effect of a motion blur reduction mode. It will help make mouseturns much smoother at slower speeds, whereupon blur reduction benefits more.

Secondly, does DyAc work outside of monitor's refresh rate, so I won't have to enable any FPS cap (which is no good for CS:GO) ?

It is simply just a motion-quality recommendation that framerate should be matched to refreshrate. That goes with all motion blur reduction technologies (not just DyAc).

However, one can still choose to use a motion blur reduction technology (strobe backlight) without matching frame rate to refresh rate.

The moral of the story is:
- Strobing always is refresh rate matched
- Motion quality is always better quality at fps=Hz with strobe backlight technologies
- Motion blur reduction makes microstuttering more visible, including stutters from framerate-refreshrate mismatch.
- However, you can still choose to use overkill frame rates to compensate (CS:GO for example) and just "live with the unsynchronized frame rates".

You don't have to match frame rate to refresh rate. You simply have a choice between motion quality (match fps=Hz to eliminate strobe-amplified microstuttering) or lower latency (as high framerate as possible)

The good news is you can turn on/off the modes (XL2546 DyAC ON/OFF or XL2540 Blur Reduction ON/OFF) depending on the game and situation. You may have noticed by now that increasing Hz and frame rate can reduce motion blur -- however, using a motion blur reduction mode can reduce motion blur much more dramatically to one-tenth its original (or less) -- much closer to a CRT.

[speancer]

Thank you for answering! Would you mind covering a few more questions?

You presume correctly, I have tested ULMB a little bit after I first got this new display, although after I saw how much it degrades brightness, I refused to use it at all. I tested it now with the test you provided with a link, got to admit, it makes a big difference with ULMB enabled, sadly the brightness impact and refresh rate impact are not worth it, in my opinion. Also it does not help at all with trailing behind fast moving objects.

Do all other motion blur reduction technologies impact brightness that much?

So, does DyAc do exactly the same thing like ULMB with no brightness penalty, or is it a better technology overall? From what I see, it's better, because it's presented as also being able to reduce ghosting.

What I also seek is how to reduce ghosting; right me if I'm wrong - it's how that trailing behind moving objects is called, correct? When you move the camera with your mouse and look at an opponent's model (or any other object), it leaves a phantom-like trail behind. From what Zowie is advertising, DyAc also fights off ghosting. They present it here, please have a look:

https://www.youtube.com/watch?v=J41BBngD4As

That's basically ghosting reduction, is it not?

About flicker-free being disabled, does it hurt eyes or something? I guess there's a reason why basically all monitors are flicker-free?

I've always used 400 DPI for Counter-Strike, for years, I did not notice any stuttering with ULMB enabled in CS:GO.

And back to DyAc, I've seen a thing or two about something called strobe crosstalk around here. Is that negative effect only visible if FPS drops to at least 1/2 of refresh rate? What happens if FPS fluctuates below and above the refresh rate with DyAc enabled? Let's say I have that 240 Hz display with uncapped FPS, it goes from 200 to over 400 FPS from time to time, will that result in any problems with DyAc? Or, for example, if I cap frame rate at the refresh rate value (like you advice for best motion quality), will drops below 240 FPS result in any negative effects with DyAc enabled?

[Chief Blur Buster]

Do all other motion blur reduction technologies impact brightness that much?

Not all of them. There's also bright ULMB implementations (i.e. only 25% loss in brightness, most 25" 240Hz panels can do ULMB with little brightness loss) but most 27" ULMB dims quite a lot. It's simply a matter of voltage-boosting the strobe backlight flashes to compensate for the briefness of the strobe backlight flash. DyAc uses a heavy amount of voltage-boosting to an extent that it successfully fully compensates for the brightness loss.

So, does DyAc do exactly the same thing like ULMB with no brightness penalty, or is it a better technology overall? From what I see, it's better, because it's presented as also being able to reduce ghosting.

DyAc and ULMB behave the same way. 120Hz for 120Hz, it will look relatively identical, except significantly brighter. That said, be noted you may get a bit more strobe crosstalk at 240Hz than at 120Hz, due to the way LCD GtG overlaps multiple refresh cycles. DyAc is one of the better full-240Hz-capable strobe backlight modes.

What I also seek is how to reduce ghosting; right me if I'm wrong - it's how that trailing behind moving objects is called, correct? When you move the camera with your mouse and look at an opponent's model (or any other object), it leaves a phantom-like trail behind. From what Zowie is advertising, DyAc also fights off ghosting. They present it here, please have a look

Yep, that's ghosting/coronas.

We've got images of ghosting at LCD Motion Artifacts 101

You will still have something similar called strobe crosstalk (The faint afterimage you see in ULMB, like at Strobe Crosstalk FAQ). In the best case, it's much fainter than the ghosting/coronas in non-strobed mode (non-DyAc non-ULMB). In the worst case, it is worse than the ghosting/coronas in non-strobed mode.

For BenQ (XL2540 and XL2546), it definitely is less than non-strobed. If you want brighter, definitely XL2546 over XL2540 as the DyAc-branded mode is brighter than the XL2540 version (about the same brightness as the ULMB you are seeing).

About flicker-free being disabled, does it hurt eyes or something? I guess there's a reason why basically all monitors are flicker-free?

Everybody sees differently. That said, some of us here have motion blur eyestrain so the motion blur reduction compensates fully (lesser evil to enable a perfect synchronized flicker that is tuned to intentionally eliminate motion blur). There are people here who get headaches from PWM dimming but not headaches from motion blur reduction. Everybody is different -- some see stutters more, some see tearing more, some see flicker more, some see motion blur more, etc. You may be picky about different things.
I've always used 400 DPI for Counter-Strike, for years, I did not notice any stuttering with ULMB enabled in CS:GO.

And back to DyAc, I've seen a thing or two about something called strobe crosstalk around here. Is that negative effect only visible if FPS drops to at least 1/2 of refresh rate?

No, you will always get duplicate images on impulsed displays for frame rates far below Hz, on all impulsed displays (CRT/plasma/phosphor/strobing/ULMB/DyAc/ELMB/whatever that uses flicker technologies to eliminate motion blur).

Strobe crosstalk (fps=Hz) and multi-strobed images (fps below Hz) have different causes despite looking similar. And they can both happen simultaneously (3 images -- 2 multi-strobed images combined with 1 additional faint image caused by strobe crosstalk).

Duplicate images is caused by flashing the same frame multiple times. It is fixable by increasing frame rate, or decreasing refresh rate to match frame rate.

Strobe crosstalk is caused by LCD GtG being too slow to fit in one strobe flash (pixel response overlapping multiple refresh cycles). It is a law-of-physics issue.

One or the other can happen, or both can happen at the same time.
Not everybody is picky about it.

What happens if FPS fluctuates below and above the refresh rate with DyAc enabled? Let's say I have that 240 Hz display with uncapped FPS, it goes from 200 to over 400 FPS from time to time, will that result in any problems with DyAc? Or, for example, if I cap frame rate at the refresh rate value (like you advice for best motion quality), will drops below 240 FPS result in any negative effects with DyAc enabled?

Please do more homework with ULMB. Play more with ULMB. The behaviors of ULMB is exactly the same as the behaviors of DyAc, except DyAc is brighter and lower lag.

"Result in any problems with DyAc" has no simple answers -- no Yes or No answer -- I can only ask you to see for yourself. The moral of the story is that there are general recommendations such as fps=Hz for motion quality, or overkill framerates (fps>Hz) for lower-lag. For some people, all frame rates are all playable with strobing (ULMB or DyAc). Everybody is picky in different ways. Some people dislike strobing only because of lag. Others dislike strobing only because it looks too jittery with their favourite low-DPI that they normally use non-strobed.

For other people who hate stutters, only fps=Hz looks beautiful. Basically ultra-high-DPI mouse + fps=Hz matching = the only way to get things TestUFO-smooth in videogames.

Also, don't forget to see HOWTO: Using ULMB Beautifully or Competitively.
Now, mind you, ULMB doesn't benefit CS:GO nearly as much as crosshairsless games as seen in the FAQ above, due to the fixed-gaze situation (motion blur reduction only helps eye-tracking situations, not fixed-gaze situation). But XL2546 DyAc makes it low-lag enough and bright enough, that some pros now keep it turned on. Also, it can help with aim control during spraying an enemy in a game -- the recoil and the vibrations -- all that can create display motion blur that makes it hard to continually aim a spray. The motion blur reduction can help with that too.

You already have ULMB. Test it out some more in solo/bot play. Sure, the lower-Hz 165Hz ULMB is more laggy and dimmer than DyAc. Test raising mouse DPI from 400dpi to 1600dpi or 3200dpi (And lowering in-game sensitivity), combined with cleaner mouse feet and higher-resolution mousepad (needed or 1600dpi feels worse than 400dpi). You need one of those new high end sensors that does high-DPI accurately. Now test a few slow mouseturns, and you'll see mouseturns become TestUFO-smooth/sharp. Slow mouseturns as smooth as keyboard strafe left/right, without coarse/granular effects (the step-step-step effect).

Get familiar with your ULMB. Stutter mechanics are identical to DyAc. Pretend that there's no lag penalty. Pretend it's much brighter. If it grows on you ("if only if it were brighter and less laggy"), then definitely pay the premium for DyAc.

There are some ULMB implementations as bright as DyAc but BenQ has been more consistent and careful slapping the "DyAc" label only on their brightest strobed implementations, so the "DyAc" label is consistently universally bright, whereas "ULMB" can be anywhere from very dim to very bright (Depending on monitor model).

[speancer]

And back to DyAc, I've seen a thing or two about something called strobe crosstalk around here. Is that negative effect only visible if FPS drops to at least 1/2 of refresh rate?

No, you will always get duplicate images on impulsed displays for frame rates far below Hz, on all impulsed displays (CRT/plasma/phosphor/strobing/ULMB/DyAc/ELMB/whatever that uses flicker technologies to eliminate motion blur).

Strobe crosstalk (fps=Hz) and multi-strobed images (fps below Hz) have different causes despite looking similar. And they can both happen simultaneously (3 images -- 2 multi-strobed images combined with 1 additional faint image caused by strobe crosstalk).

Hmm, so you're saying there always will be this negative effect similar to ghosting when DyAc is enabled (strobe crosstalk) and it looks progressively worse when frames drop lower and lower below the refresh rate, but it's less visible than ghosting I'm experiencing on my current display? So I guess both normal ghosting and DyAc "ghosting" can appear simultaneously as well? Damn, I am confused with all this. Sometimes I don't even understand what you're writing

Is this even possible to get rid of ghosting (and similar effects caused by strobing) completely? I guess only on some super non-existent 1000 Hz display?

As for playing with ULMB and testing it - not gonna do that. Already ordered XL2546, there was a great discount today (about 100$ off), so I will experience DyAc firsthand. There are 28 days to return products purchased online where I live, so there's no problem with testing desired hardware, and I simply cannot make a decision without trying at least a few options, there are so many to choose from (took me over 10 mice and keyboards to make a final choice)! This will be my first 240 Hz display, also I have not used a TN panel for YEARS, as well as nothing below 27 inches, so I expect an unpleasant shock at first.

And about mouse settings, I've always used 400 DPI, ever since Counter-Strike 1.6, also most pro players use 400 DPI as well, but if it gets jittery with DyAc then I might try higher DPI, as you advice. My mouse can surely handle it, it's a high-end model powered by PMW3366 sensor (the flawless sensor type). I have high quality mouse feet (Corepad Skatez) and Zowie G-SR/SteelSeries QCK Heavy mousepads, both very high quality, I guess they're good for all DPI settings.

[The1Mach1ne]

400dpi * 1 sensitivity is equivalent to 1600dpi * 0.25 sensitivity just follow the man's recommendations.

Fwiw I have dyac on the xl2546s and don't notice any problems when I play crucible where frames don't go above 120. But like chief said, someone else might notice something.

But in valorant where I get 300-400 frames I run dyac+no fps cap and it feels godlike holy moly

Apex have to cap at 190 because of the engine and it still feels good to me.

My previous monitor was Alienware 2518hf and I could never make it feel good across all games.

I'm 2000dpi and 0.84 sens in Apex (24.7cm/360). None of those numbers matter other than reaching the same cm/360 cuz math

[blurbustingbunny]

Do all other motion blur reduction technologies impact brightness that much?

Not all of them. There's also bright ULMB implementations (i.e. only 25% loss in brightness, most 25" 240Hz panels can do ULMB with little brightness loss) but most 27" ULMB dims quite a lot. It's simply a matter of voltage-boosting the strobe backlight flashes to compensate for the briefness of the strobe backlight flash. DyAc uses a heavy amount of voltage-boosting to an extent that it successfully fully compensates for the brightness loss.

So, does DyAc do exactly the same thing like ULMB with no brightness penalty, or is it a better technology overall? From what I see, it's better, because it's presented as also being able to reduce ghosting.

DyAc and ULMB behave the same way. 120Hz for 120Hz, it will look relatively identical, except significantly brighter. That said, be noted you may get a bit more strobe crosstalk at 240Hz than at 120Hz, due to the way LCD GtG overlaps multiple refresh cycles. DyAc is one of the better full-240Hz-capable strobe backlight modes.

What I also seek is how to reduce ghosting; right me if I'm wrong - it's how that trailing behind moving objects is called, correct? When you move the camera with your mouse and look at an opponent's model (or any other object), it leaves a phantom-like trail behind. From what Zowie is advertising, DyAc also fights off ghosting. They present it here, please have a look

Yep, that's ghosting/coronas.

We've got images of ghosting at LCD Motion Artifacts 101

You will still have something similar called strobe crosstalk (The faint afterimage you see in ULMB, like at Strobe Crosstalk FAQ). In the best case, it's much fainter than the ghosting/coronas in non-strobed mode (non-DyAc non-ULMB). In the worst case, it is worse than the ghosting/coronas in non-strobed mode.

For BenQ (XL2540 and XL2546), it definitely is less than non-strobed. If you want brighter, definitely XL2546 over XL2540 as the DyAc-branded mode is brighter than the XL2540 version (about the same brightness as the ULMB you are seeing).

About flicker-free being disabled, does it hurt eyes or something? I guess there's a reason why basically all monitors are flicker-free?

Everybody sees differently. That said, some of us here have motion blur eyestrain so the motion blur reduction compensates fully (lesser evil to enable a perfect synchronized flicker that is tuned to intentionally eliminate motion blur). There are people here who get headaches from PWM dimming but not headaches from motion blur reduction. Everybody is different -- some see stutters more, some see tearing more, some see flicker more, some see motion blur more, etc. You may be picky about different things.
I've always used 400 DPI for Counter-Strike, for years, I did not notice any stuttering with ULMB enabled in CS:GO.

And back to DyAc, I've seen a thing or two about something called strobe crosstalk around here. Is that negative effect only visible if FPS drops to at least 1/2 of refresh rate?

No, you will always get duplicate images on impulsed displays for frame rates far below Hz, on all impulsed displays (CRT/plasma/phosphor/strobing/ULMB/DyAc/ELMB/whatever that uses flicker technologies to eliminate motion blur).

Strobe crosstalk (fps=Hz) and multi-strobed images (fps below Hz) have different causes despite looking similar. And they can both happen simultaneously (3 images -- 2 multi-strobed images combined with 1 additional faint image caused by strobe crosstalk).

Duplicate images is caused by flashing the same frame multiple times. It is fixable by increasing frame rate, or decreasing refresh rate to match frame rate.

Strobe crosstalk is caused by LCD GtG being too slow to fit in one strobe flash (pixel response overlapping multiple refresh cycles). It is a law-of-physics issue.

One or the other can happen, or both can happen at the same time.
Not everybody is picky about it.

What happens if FPS fluctuates below and above the refresh rate with DyAc enabled? Let's say I have that 240 Hz display with uncapped FPS, it goes from 200 to over 400 FPS from time to time, will that result in any problems with DyAc? Or, for example, if I cap frame rate at the refresh rate value (like you advice for best motion quality), will drops below 240 FPS result in any negative effects with DyAc enabled?

Please do more homework with ULMB. Play more with ULMB. The behaviors of ULMB is exactly the same as the behaviors of DyAc, except DyAc is brighter and lower lag.

"Result in any problems with DyAc" has no simple answers -- no Yes or No answer -- I can only ask you to see for yourself. The moral of the story is that there are general recommendations such as fps=Hz for motion quality, or overkill framerates (fps>Hz) for lower-lag. For some people, all frame rates are all playable with strobing (ULMB or DyAc). Everybody is picky in different ways. Some people dislike strobing only because of lag. Others dislike strobing only because it looks too jittery with their favourite low-DPI that they normally use non-strobed.

For other people who hate stutters, only fps=Hz looks beautiful. Basically ultra-high-DPI mouse + fps=Hz matching = the only way to get things TestUFO-smooth in videogames.

Also, don't forget to see HOWTO: Using ULMB Beautifully or Competitively.
Now, mind you, ULMB doesn't benefit CS:GO nearly as much as crosshairsless games as seen in the FAQ above, due to the fixed-gaze situation (motion blur reduction only helps eye-tracking situations, not fixed-gaze situation). But XL2546 DyAc makes it low-lag enough and bright enough, that some pros now keep it turned on. Also, it can help with aim control during spraying an enemy in a game -- the recoil and the vibrations -- all that can create display motion blur that makes it hard to continually aim a spray. The motion blur reduction can help with that too.

You already have ULMB. Test it out some more in solo/bot play. Sure, the lower-Hz 165Hz ULMB is more laggy and dimmer than DyAc. Test raising mouse DPI from 400dpi to 1600dpi or 3200dpi (And lowering in-game sensitivity), combined with cleaner mouse feet and higher-resolution mousepad (needed or 1600dpi feels worse than 400dpi). You need one of those new high end sensors that does high-DPI accurately. Now test a few slow mouseturns, and you'll see mouseturns become TestUFO-smooth/sharp. Slow mouseturns as smooth as keyboard strafe left/right, without coarse/granular effects (the step-step-step effect).

Get familiar with your ULMB. Stutter mechanics are identical to DyAc. Pretend that there's no lag penalty. Pretend it's much brighter. If it grows on you ("if only if it were brighter and less laggy"), then definitely pay the premium for DyAc.

There are some ULMB implementations as bright as DyAc but BenQ has been more consistent and careful slapping the "DyAc" label only on their brightest strobed implementations, so the "DyAc" label is consistently universally bright, whereas "ULMB" can be anywhere from very dim to very bright (Depending on monitor model).

You mentioned that some people are sensitive to PWM but not to DyAc, that's interesting. Do you recall who has had this experience? And are there people who get headaches from DyAc?

[Chief Blur Buster]

You mentioned that some people are sensitive to PWM but not to DyAc, that's interesting. Do you recall who has had this experience? And are there people who get headaches from DyAc?

Dozens of forum posts since 2014 have attested to this fact.

It's simply explained by the fact that PWM dimming generates stroboscopic artifacts during motion. This is extremely uncomfortable to the eyes, much moreso than the flicker itself in many situations. For some people, it feels like a serrated knife to the eyes, in terms of motion comfort. From LCD Motion Artifacts:



Now, if you synchronize PWM to one flash per frame, motion can look more comfortable.



The flicker can still produce discomfort problems, especially from stroboscopic effects and phantom arrays (The Stroboscopic Effect of Finite Frame Rates). However, this is minimized if you're flashing only once per frame.

For comfortable DyAc, you ideally want:

- Framerate matching refresh rate
- Microstutters eliminated (including mouse: Use 1600dpi or more)
- Low strobe crosstalk. Easiest way to do this is hertzroom. 120Hz strobing on a 240Hz monitor can look better than 120Hz strobing on 144Hz, because it's easier to hide LCD GtG pixel transitions between refresh cycles.

The 182Hz DyAc trick + 182fps cap + high DPI mouse, can make BenQ DyAc look better.

[Conan]

thanks everyone in this topic! very informative and helpful.
as someone who is awaiting xl2546s i'd ask the most questions speancer asked.
very nice.