Blur Buster Eve Spectrum Strobe Tuning Completion

Discalimer: I have not seen the Acer 1440p 240Hz. Differences between different panels can exceed tuning quality differences. I’ve seen some 240Hz outperform best-tuned-effort 144Hz, and I’ve seen some 144Hz outperform best-tuned-effort 240Hz, just because of panel quirks. Or you see situations of overlap where certain refresh rates are superior on one, and other refresh rates are superior on the other. This is my experience over the last 10 years. Thusly, I have no idea of Spectrum 144 vs Acer 240 strobe quality, having not seen that panel yet.

The “jack of all trades” monitor is still a holy grail that is hard to reach, trying to combine “wide gamut” + “zero strobe crosstalk” + “high Hz” simultaneously is extremely difficult to achieve. But to push KSF phosphor behaviours less visible than plasma artifacting/ghosting, is still an achievement by Blur Busters. It’s a difficult tuning job that required a lot of firmware modifications on behalf of Eve too.

However, any “Blur Busters Approved” (only non-KSF TN/IPS currently can achieve that gold trophy) and “Tuned by Blur Busters” (kind of like a silver trophy) will generally be more flexible in strobe tuning capabilities. With lots of opportunities to out-tune a manufacturer’s factory strobe tuning. Just like colorimeters can out-tune a manufacturer’s color tuning for many reasons (panel variances, temperature variances, use-case variances, etc).

…Now for apples versus apples (same panel)

If the upcoming 1440p 240Hz Eve uses the same panel & backlight as the Acer 1440p 240Hz, I’m pretty sure I can out-tune Acer in an apples-versus-apples. Winky wink. :wink: Plus, cherry on top, since the EVE 240Hz likely will support Strobe Utility too, you get to attempt to tune even better than factory (compensate for temperature & panel variances).

Currently, no Acer monitor supports Strobe Utility (at this time), as Acer currently hasn’t opted-in for Strobe Utility support, so that’s an automatic strike already since good DIY strobe tuning can exceed manufacturer tuning due to environment / temperature / panel variances.

It’s funny how almost all manufacturers open their door fully for DDC/CI commands for DIY colorimeters and optional DIY color tuning. But many manufacturers slam shut the door to optional DIY strobe tuning in an act of self-sabotage of strobe quality/flexibility for prosumers.

For that, I give much kudos to EVE for deciding to keep the Blur Busters Strobe Tuning Standard control codes accessible in retail firmware, making optional DIY strobe tuning possible for advanced users.

Blur Busters is slowly successfully working to change that by standardizing strobe tuning by giving advanced users access to PulsePhase-PulseWidth-OverdriveGain adjustment trio (by DDC/CI command), combined with “strobe any Hz” support (retro friendly strobing too) instead of limited presets (unlike NVIDIA ULMB limited choice).

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This has to be one of the best kept secrets/surprises/presents given to us. I can’t thank Eve enough and I can honestly say, as honest as possible without using it, that it will have been worth the wait to get a monitor that was done correctly. Maybe part of the reason for the shipping delay to the end of June was because of this but hopefully this should put all the doubters and haters to rest. With technology advancing so fast that is stays beyond what we can see, perfection is a term for what we desire most but for only as far as we can see. Once we gain what we think is perfection, we can then see how much better it can be thus perfection is never really attainable. I am so excited.

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Thanks for all this in depth knowledge!
This is really one of the things I didn’t known exists but seems to have a pretty big impact on the perceived image quality.

I’ve a question about the Modes combined with Freesync.
If we select the pretuned Option for 144Hz, what probably a lot of people will do for gaming, and Freesync is active, does the strobing still work or does the monitor deactivates the feature if VRR is detected?

If VRR is active and the FPS of the game moves between 100-144, does the pretuned option for 144Hz still works and the picture just won’t as perfectly tuned as if the FPS stays on 144?
Or what would be the consequences of this setting?

And lastly a general question about „Static“-Tuning and VRR-Tuning. (For a complete Noob in this Field of tech😁)
Currently the monitor is tuned on specific Hz, so these values are written into the monitor and the monitor handles all necessary options. Can be user selected.
If we want to use the VRR-Feature there has to be some kind of algorithm which can select the necessary options on the fly. This algorithm is stored on the monitor (?) or is some kind of software used for this?
Is this generally correct?

Thanks in advance! This is some pretty cool tech!

@Lore_Wonder has EVE thought about adding VRR Support? I think it would be quiet good to use VRR and Strobing, even more in demanding 4K Games.

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Short answer: Yes.

While I wasn’t part of VRR tuning (at this stage), the pre-tuned is good enough that you won’t notice artifacts over such a modest framerate-fluctuation range. It’s less noticeable than most early FreeSync monitors.

It’s something you might notice only during sudden framerate changes like 140fps → 65fps → 140fps and the like. But it’s a lesser of evil (for majority of people) than the stutter-erasing behavior of VRR.

For those unfamiliar with Variable Refresh Rate:

For those unfamiliar with variable refresh rates, view www.testufo.com/vrr for an example of the benefits of VRR.

In short, it is an excellent single framedrop eraser, so things like 60fps->59fps->60fps becomes stutterfree, as well as 144fps->143fps->144fps too. And smooth framerate changes are stutterless, as framerate-change stutter (from rendertime variances) is effectively erased. If you hate stutters, then VRR is heaven. 57fps looks like perfect 57Hz VSYNC ON. 142.56fps looks like perfect 142.56Hz VSYNC ON. No tearing, no stutter, looks liker permanent framerate=Hz despite framerate changes*

*Exceptions: Certain stutters like disk-access stutters are not erased as well as rendertime-variance (GPU workload change) stutters.

This is done by realtime synchronizing refresh rate to frame rate, and refresh rate can change over 100 times a second. Basically refresh cycles are software-driven with VRR. Anytime a video game Presents() a frame to the monitor, the monitor refreshes immediately, right there, on the spot, without any fixed refresh schedule. As long as frame rate is within VRR range.

However, VRR tuning often requires overdrive to be optimized for a specific Hz, or for the monitor to have dynamically variable overdrive that varies in realtime with frametimes. Right now, at this moment, dynamic overdrive isn’t available but the good news is that unlike yesteryear IPS and VA panels, the newer “Fast IPS” panels (often called “1ms GtG IPS” panels, although those are the best-case synthetic GtG measurements of specific overdriven colors). Fast IPS panels like these only need minor variances in overdrive between min-Hz and max-Hz.

One variable that creates issues with varying Hz on an LCD, is the need to varying LCD overdrive slightly, because stronger overdrive is needed at higher Hz for a neutral motion look (no ghosting, no corona). For those unfamiliar with LCD motion artifacts, see longtime Blur Busters resources LCD Motion Artifacts 101 and then LCD Overdrive Artifacts (animated GIFs).

For non-strobed, when “Overdrive = User Defined” and you adjust User Defined, I discovered that the best Overdrive settings were approximately (+/- 2 clickpoints):

50Hz - User Defined 2
60Hz - User Defined 3
100Hz - User Defined 8
120Hz - User Defined 13
144Hz - User Defined 16

There are 64 possible user accessible overdrive levels on EVE Spectrum (a large number of overdrive settings compared to most monitors!). A delta of only 14 Overdrive Gain points (out of a possible 0 to 63 overdrive settings for User Defined overdrive), means that it’s possible to tune overdrive to an approximate sweet spot without noticeable variable overdrive-artifacts for a small framerate change. So a 100fps-to-144fps range, you likely won’t see any overdrive-artifacts differences.

Also, on some panels, the need to vary overdrive can be less during VRR than with fixed Hz because VRR is fixed-scanrate, with a varying blanking interval between refresh cycles. The technical explanations of this is a bit complex, but this is what I’ve found.

The stutterless principle of VRR is probably way more noticeable than the extremely tiny overdrive differences between similar frame rates. It’s mainly during sudden framerate changes such as 144fps → 60fps → 144fps, that you might notice overdrive artifacts appear. Since overdrive at 144fps might be neutral (no ghost, no corona) but have a corona at 60fps.

If you are new to VRR, then don’t worry about it. These are usually only visible to picky people paying extremely close attention to motion. There is definitely no noticeable overdrive differences between adjacent Hz (eg. 139 Hz versus 141 Hz), as it requires a bigger difference in Hz to notice overdrive artifact differences of the same overdrive setting. Even small ranges (100fps-144fps) should not produce anything noticeable to >99% of people – it is far less noticeable than a single frame drop of non-VRR.

Note: It is also theoretically possible that future firmware upgrades could add realtime dynamic overdrive in sync with varying refresh rate, but it all depends on the panel’s hardware capabilities and how programmable the panel is. The simplest algorithm is probably a math formula that automatically calculates OD gain for the current refresh cycle, based on the time interval between current and last refresh cycle. However, more advanced algorithms require prediction of future frametimes. Some hardware simply don’t have the capability to easily do realtime dynamic overdrive, since it requires processing capabilities that may simply be not available during VRR operation on some panels.

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Really thank you for the explanation!
This was a really easy to understand explanation on VRR.
I had a look in your 101 Series Posts and some Forum threads, now I think I’ve a very basic understanding, thanks for that.
Really looking forward to the monitor, this will probably be like day and night compared to my 4k@60Hz Monitor :grin:

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Update About VRR Strobing: Beginning Work On It

EVE and Blur Busters are now starting talks about adding variable refresh rate motion blur reduction (aka “VRR strobing”) to firmware.

Please note that Blur Busters, as a third party vendor, is currently vetting the backlight hardware for any theoretical hardware limitations preventing reasonable quality variable refresh rate (VRR) strobing. The good news is that the backlight controller seem to be flexible and should meet the needs for VRR strobing.

The biggest challenge is communication between English and Mandarian, but Blur Busters now has years of experience to many scaler/TCON vendors in Asia (China, Hong Kong, Taiwan, Japan, Korea).

Apparently, this means Eve likely will be the recordholder of the world’s first post-shipment firmware upgrade to add VRR strobing post-release.

The usual caveats about KSF phosphor still applies, in the “Worse than CRT, but better than plasma” kind of way – which apparently is far more than good enough for a lot of people.

…the freedom that EVE gives me to talk about “behind the scenes” information, allows me to tall me some really interesting technical stuff, of the famous Blur Busters flavor. So here’s some technical information below. I have vetted the below that they are already public knowledge elsewhere at places like “Society for Information Display”, academic papers, and not covered by any NDAs…

Most just want to turn strobing ON/OFF. But what’s done to make “ON” an easy toggle (without seeing bad quality) is a bit complex:

Behind The Scenes Technicals About Strobe Engineering

[Technical]
The common situation for many monitor brand names you love, is that they often work with a supplier that helps with the firmware/scaler/TCON. (such as MSTAR, Skyworth, TPV, Lehui, Samsung, etc). Eve fits this standard Development Life Cycle chain of a monitor vendor, as they are using Lehui

In the panel programing chain, there may be multiple suppliers involved (e.g. MSTAR working with a AUO panel) or the same supplier (e.g. Samsung working with a Samsung panel). In this case, Suzhou Lehui (Eve’s supplier) works very closely to LG, the manufacturer of the Eve panel.

Now, the fun begins for strobing.

For many scaler vendors, they don’t even (yet) know what they are doing until I’ve given them exact instructions, and then they are amazed crosstalk dropped 90%. A lot doing simple DELL 60Hz panels, blindly told to add special algorithms to high-Hz backlights that are more precise than 10 microseconds (10 microseconds actually creates human-visible flicker, since 1ms MPRT varying versus 1.01ms MPRT is a 1% brightness difference!).

Overdrive Gain is simply huge numbers of overdrive settings – sometimes as many as 256 levels – but may be 32 level, 64 level, 100 level, or 128 level, depending on panel vendor. The LG scaler/TCON standardizes on 64 levels of overdrive internally, even though only 2 or 3 levels are usually exposed in the menus. Mind you, Blur Busters always admonishes making all levels accessible to user, because of temperature reasons and panel lottery reasons, sometimes a 2/64th change makes a big difference in a cold winter room versus hot summer room.

For those who usually don’t care about milliseconds, but interested in some easy Popular Science explanations, read the Milliseconds Matters Thread in the Blur Busters Forums. It’s shocking how many specific kinds of sub-milliseconds can become human visible.

The complexity is higher for VRR strobing than non-VRR strobing. There’s lots of exceedingly exact scientific instructions involved in VRR strobing. This is what Blur Busters is increasingly cable of doing; we are able to successfully communicate instructions for multiple generic high quality strobe algorithms at better-than-NVIDIA-ULMB-quality, for extremely low cost. That’s why EVE hired Blur Busters to help them with this work – because we can do it at only a very tiny fraction of the monitor’s development budget.

Now if a hardware limitation is discovered, it has to be discovered in early prototypes, in the EVT, DVT, PVT prototype sequence.

  • EVT aka Engineering Validation Test (prototype)
  • DVT aka Design Validation Test (prototype)
  • PVT aka Production Validation Test (mass production unit)

So if a firmware bug preventing a specific strobe feature (e.g. lack of 100% strobe phase range capability), it ideally has to be discovered in EVT or early DVT, then the electronics circuit board fixed to prevent a strobe backlight tuning limitation. Thankfully, EVE successfully fixed all hardware limitations before PVT. The only thing I couldn’t fix was the KSF phosphor built into LG NanoIPS panels, but it’s at least tunable to be better than plasma displays (less phosphor trails than plasma).

While not strictly necessary for FastIPS panels, occasionally, esoteric strobe tuning stuff such as 256x256 Overdrive Lookup Tables replaces the old 17x17 Overdrive Lookup Table, or there’s a Y-Axis Overdrive Gain Formula (overdrive increases along the vertical axis of the display, to speed up LCD GtG near bottom edge).

Mandatory Strobe Engineering by Blur Busters At Blur Busters, the standard “minimum-needed-to-beat-NVIDIA-ULMB” formula Blur Busters commonly works for strobe tuning mainly focuses on these adjustments:

  • Strobe Pulse Phase (full 100% adjustability of PWM relative to VBI)
  • Strobe Pulse Width (1% to 25% minimum)
  • Overdrive Gain (as many clicks as the scaler/TCON lets me have)
  • Strobe-Any-Hz Support (no fixed strobe presets are allowed at Blur Busters, we usually refuse to work with vendors that only provide fixed strobe refresh rates)

Eve successfully met all the Blur Busters Mandatory Minimum strobe-programmability specifications, and the shipping firmware includes all of this Blur Busters mandated minimum capability.

Optional Additional Strobe Engineering Enhancements Now, further possible optional additional strobe-improving algorithms that can widen the crosstalk-free strobe zone taller:

  • 256x256 overdrive lookup tables instead of common 17x17 overdrive lookup tables.
    Right now, we usually work with existing 17x17 OD LUTs. This can lead to certain colors that are suboptimally overdriven for panels with very odd GtG heatmaps at finer granularity than 17x17 OD LUT can solve. Fortunately Fast IPS usually is forgiving of 17x17 OD LUTs, while VA panels more badly need 256x256 OD LUTs for strobe-mode.
  • Y-Axis overdrive gain formula (faster GtG for bottom edge of panel)
    This is because not all pixels refresh at the same time, and the bottom edge refreshes late, meaning less time to finish LCD GtG before the global strobe backlight flash
  • Refresh Rate Headroom / Large Vertical Totals / Internal scan conversion to create large multi-millisecond blanking intervals between refresh cycles to hide LCD GtG
    The world’s first zero-crosstalk IPS LCDs panels successfully achieve it with an approximately ~10ms VBI. A 1/240sec scanout on a 72Hz panel creates a blanking interval of 9.7 milliseconds between refresh cycles – sufficient enough to hide most of real-world GtG of many LCDs in the total darkness cycle between strobe backlight flashes.

Most monitors use outdated 17x17 OD LUTs because papers found they were “good enough” for a typical 60Hz panel, coming from this Outdated paper from year 2012. But we’re in the 360Hz era with strobe backlights. Blur Busters intuitively know things such as how 17x17 OD LUTs (fine for non-strobe) sometimes to worsen backlight strobing due to a human-visibility-amplifying interaction researchers did not test for, that only happens in strobe-backlight mode, on panels with sharp-cornered GtG heatmaps (especially VA panels at specific temperatures: a real-world 15C bedroom in middle of winter).

Most factories just QA test panels at 20C, but real world rooms are colder/hotter – like artic or tropics. It’s part of why we’re huge advocates of exposing the entire OD GAIN range to the end-user onscreen menu (at least as an optional “User Defined” Overdrive option). Very major quality problems of 17x17 begins to appear as the refresh rates and strobing a pushed concurrently, simultaneously with real-world temperatures. Just to save a few bytes of scaler RAM, versus a 256x256 OD LUT (64 kilobytes). This ain’t year 2012 in Kansas, toto.

These generic cheap strobe-improving techniques are now fairly widespread for many years. It made possible the world’s first zero-crosstalk IPS LCD panels (at least for non-KSF panels) when using sufficient refresh rate headroom to hide LCD GtG pixel response completely away from human eyes in humongous VBIs between refresh cycles (Such as 1/240sec scanouts strobed at 60Hz-to-120Hz).

Much of our generic strobe tuning work now out-tunes many patented strobe algorithms. A lot of vendors reverse-engineered techniques that many 3D monitors and 3DTVs used (e.g. Y-Axis Overdrive Formula for increased OD Gain near bottom edge of panel), and Blur Busters have followed suit with new inexpensive tuning methods that formerly cost a lot to do.

Especially with higher-Hz, clearer motion, less motion blur, lifting the fog that formerly hid tiny millisecond-dependant image artifacts. The scientists that say “Humans can’t tell apart events 10ms apart” are measuring only 1 item out of 100+ possible effects. Blur Busters, instead casts that massive mile-wide scientific net (which you’ve seen of our research writings at www.blurbusters.com/area51 already) and know which of those specific milliseconds actually is noticeable to Grandma that can’t tell apart DVD-vs-HDTV. We filter the FUD and target the important milliseconds.

The confidence level, currently is pretty high, but I wanted to publish the usual Blur Busters caveats, as Blur Busters is always cautious about predicting capabilities. As most readers of Blur Busters already know, Blur Busters is always carefully more conservative about talking about features until they hare successfully developed. We are not exaggerating when exceedingly exact strobe algorithms can get lost in communication difficulties (e.g. English-Mandarian), and often I am hired to fly out over the Pacific Ocean to teach a class room at a display vendor [PHOTO].

A lot of overseas engineers are very new to motion blur reduction physics, or the more complex variable refresh rate strobing physics.

From end, I can confirm that the strobe-tunable firmware (both the easy preprogrammed tuning & the advanced Strobe Utility tuning capability) made it to the mass production (MP) model.
[/Technical]

[shamless plug…]
Blur Busters often is ahead of outdated scientific papers (Google Scholar on 17x17 Overdrive LUTs), which is why mere Blur Busters Area 51 Articles has now become cited by more than 20 peer reveiwed conference papers – a lot is far ahead of industry, thanks to our ability to simplify general-purpose display motion blur knowledge. The flagship Blur Busters Area 51 articles are literally elevated to textbook reading status by the display industry.

Blur Busters one of the few companies in the world who can assist firmware vendors in successfully adding major strobe features enhancements post-shipment. We are one of the world’s best debuggers of strobe bugs, and most firmware vendors save a lot of money hiring Blur Busters services, even as a third-party strobe quality validation laboratory. In many cases, we have successfully prevented a few product recalls with post-shipment firmware fixes, and even fixing fatal frameskipping bugs (240Hz pluague) for multiple vendors before shipment, etc.
[/shameless plug…]

Hope this was useful technical reading about behind-the-scenes of strobe quality improvement!

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Only thing I disagree with in this whole writeup is the ‘shamelss plug’ tag - I argue it is a well-deserved plug.

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Could we see a temperature controlled display in the near future or that something too complex to implement ?

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I really appreciate your time spent and continued added answers and explanations into how this is all working. I’m learning a lot and it will make me re-think every future monitor/tv/screen purchase I make. I also really appreciate Eve for allowing this to happen and how transparent they have been with everything, making sure that they only speak facts and not speculation.

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For Advanced Users: Large Vertical Total Support!

Purposes: Reduce input lag, reduce strobe crosstalk

Good news! I was able to reduce 60 Hz strobed emulator latency by almost 10 milliseconds with a custom signal timing!

Apparently, EVE Spectrum has undocumented support for Quick Frame Transport (at least on DisplayPort)

This custom timing reduces strobe latency by almost 10 milliseconds, by transmitting a 60 Hz refresh cycle in 1/144sec, allowing it to be strobed quicker/sooner. Instead of a refresh cycle transmitted and refreshed in 16.7 milliseconds (1/60sec), the 60Hz refresh cycle is transmitted over the cable & painted realtime onto the screen in only 6.94 milliseconds (1/144sec) in total darkness, before the strobe flash.

For best strobe tuning quality, you want these settings in Eve Strobe Utility for 2160p 60Hz VT5400:


(Important: These settings are only useful for this specific custom mode)

In addition, it also can reduces strobe crosstalk, because of the unusually large blanking interval (10ms) of this Large Vertical Total (Quick Frame Transport) signal; which hides more LCD GtG in darkness between strobe flashes.

I am testing the MP firmware already installed in shipping Eve Spectrums; so the above custom 60 Hz QFT / Large VT mode will benefit all 60fps VSYNC ON latency material (such as emulators).

The panel apparently has undocumented support for Large Vertical Totals / Quick Frame Transport. A pleasant surprise, even to myself – it was not a priority of this work, but the panel is already horizontal scanrate multisync, which is the proper method of low-latency 60Hz while also having low-latency 144Hz.

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Optional Eve Strobe Utility Download for Advanced Beta Testers

Old post follows:

This is what the optional advanced-user strobe calibration utility looks like, for users who would like to do DIY strobe tuning. (This is the Eve skinned version of the free strobe utility Blur Busters offers to multiple vendors)

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Excellent news! This will make the advanced users extremely happy, for sure!

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I got my Spectrum last Friday and I’m about to dive into strobing. Is the Eve strobe tuning utility linked here the latest version? I’m on firmware 101, anything I should know, bugs, tricks, etc?

I’ve done strobing on a few monitors over the last few years, starting with the Dell S2716DG with ULMB. Excited to get it working on the Spectrum.

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Yes, currently. You can go ahead and download!

Remember, Strobe Utility is not mandatory to get strobing working, as pretuned strobe is factory installed for 50Hz, 60Hz, 100Hz, 120Hz and 144Hz modes.

That said, Strobe Utility is very immensely useful for advanced users:

  • improving strobe quality during custom modes (e.g. custom Hz and custom Vertical Totals)
  • adding a small improvement to compensate for panel variance (lottery)
  • compensating for panel temperature (cold LCD having slower GtG that needs a bit more Overdrive Gain to reduce crosstalk)

Regardless of parameters, to get best motion blur reduction on any monitor, make sure you choose a resolution and refresh rate where you can easily strobe at framerate=Hz, getting 4K 144fps is hard on many GPUs. So test framerate=Hz strobing to witness best motion handling.

Remember to also test real-world games too (or even things like Google Maps panning / browser scrolling), not just TestUFO, as red phosphor ghosting will be less visible in game material than the TestUFO crosstalk test.

Let me know what your experiences is like, I’m eager to hear your experiences.

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By the end of this month, I will have a dedicated webpage for Blur Bisters Strobe Utility for Eve monitors, so reviewers can understand DIY strobe tuning!

image

For now, reviewers should download from:

The new page will be much easier to follow than the old BenQ utility.

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Looking forward to this! Thank you!

also you should do a tri display span setup… with the Spectrums… just to show it off.

Unfortunately 1 of the monitors is at my other office, so I can’t do a tri-span right now – but good idea!

Also, one thing I noticed about the YouTube Optmium Tech review is much worse than my unit - I recognize it as firmware V100R848 or older. They must have tested firmware V100R848 or older, rather than V100R852 or newer.

P.S. For future review units sent out, Eve ideally should get them pre-upgraded to newer public firmwares if you can; although some reviewers like RTINGS buy anonymously to avoid manufacturer cherrypicking (for good reason).

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I have created a new master thread for Eve Strobe Utility:

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Yes, Blur Busters is working on (hopeful) VRR strobing for inclusion in future firmware upgrade

This is the correct exact quote of what I said in the other thread about VRR strobing support. Yes, working on it. But no timeline yet. The backlight controller is apparently precise enough to be potentially reprogrammed to add VRR strobing.

Nominally, the hopeful goal is:

  • Add new DDC commands specific to VRR strobing (which may include one or more of: VRR Strobe Enable, VRR Strobe Minimum Hz, VRR Strobe Phase, VRR Strobe Phase Slew Velocity);
  • Ability to adjust minimum strobe Hz (to allow users to choose between retro-friendly VRR strobing versus flicker-reduced VRR strobing) to let users choose VRR strobing compromise point;
  • Extend Eve Strobe Utility to let users adjust VRR strobing thresholds!
  • Keeping VRR strobing compatible with all VRR video sources (even XBox VRR, HDMI VRR, FreeSync, G-SYNC Compatible)

The low-framerate anti-flicker algorithms can interact badly with LFC algorithms, so that’s another wildcard to solve. But there are solutions around this.

Nice VRR strobing ideally requires the ability to seamlessly execute an antiflicker algorithm to prevent flicker at low frame rates, while also adding an optional flywheel-style “momentum-based” strobe phase slew to soften flicker of sudden framerate changes.

Again, no promises – there originally was no plans for me to add VRR strobing, partially because it was uncertain if KSF could be tuned well enough.

But this is a fantastic opportunity where Eve wants to do this & Blur Busters wants to do this. We’re eager.

Vetting is still under way: Still confirming VRR strobe flexibility

Current stage of VRR strobe work is “vetting” (80% complete) – researching / testing / evaluating my Spectrum unit whether there’s no weak links preventing usable VRR strobing – and “contract extension signing” (Between Blur Busters and Eve). Once the early shipments, me fully vetted an MP unit, their critical firmware fixes settles – I’ll go full throttle on VRR strobing work.

For a rough ballpark of timing, “this is something I intend to try to complete this summer” type of thing – with a deadline safety margin of “this is something I intend to finish by end of this year” – but only if vetting confirms VRR strobing is fully possible.

(Everybody who monitors Blur Busters know that Blur Busters famously runs on Valve Time but delivers good stuff when finally delivered – but this is being expedited as much as possible, while balancing my multiple display-manufacturer customers in sequence. Parts shortages by all have slowed me down quite a bit too)

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Skip this post if not interested in strobed VRR.

[Commentary about Strobed VRR]

Don’t use VRR strobing until you’re familiar with VRR individually and strobing individually.

VRR allows 60fps to become 59fps and back to 60fps, without you seeing the framedrop stutter. It prevents a lot of stutters from becoming human-visible because monitor actually waits for your game to deliver the frame, rather than refreshing on a fixed schedule (out of sync with frame rate).

  1. First, get familiar with strobing and what it’s good for.
    Pro: Strobing is good for motion blur reduction (Animation: www.testufo.com/blackframes)
    Pro: Strobing is amazing if you can do framerate=Hz (e.g. permanent 120fps at 120Hz)
    Pro: Strobing is amazing if you love CRT/plasma quality motion
    Con: Strobing is terrible for amplifying microstutters if your game is stuttery
    Con: Strobing can flicker if it’s low Hz, and picture can be too dim.
    Con: Strobing can be ugly if frame rate far lower than Hz (double image effect like CRT 30fps at 60Hz)

  2. Next, get familiar with VRR and what’s it’s good for.
    Pro: Variable refresh rate is good for eliminating stutters (Animation: www.testufo.com/vrr)
    Pro: Variable refresh rate is low latency, low stutter, no tearing, flicker free by default
    Pro: Variable refresh rate is the world’s lowest-latency “non-VSYNC-OFF” technology.
    Pro: Variable refresh rate realtime syncs refresh rate to frame rate (100+ times a second)
    Con: Variable refresh rate normally does not support strobing
    Con: Variable refresh rate does not reduce motion blur by itself.
    85fps VRR (at any higher Hz-capable LCD) looks identical to native 85fps 85Hz LCD. Double frame rate will halve motion blur on VRR (e.g. 60fps → 120fps → 240fps on a 240Hz VRR), but current contemporary refresh rates will not have as low-blur as strobing (needs 1000fps 1000Hz in tomorrow’s technology to do blur elimination without strobing technique).

Now, attempting to combine strobing and VRR, is an attempt to combine the benefits of the two simultaneously. The problem is when you attempt to do so, flicker can get worse with unoptimized strobed VRR which is why good strobed VRR was historically difficult to engineer.

Good strobed VRR requires:

  • High minimum Hz beyond flicker fusion threshold (e.g. 75fps)
  • Good anti-flicker algorithm to avoid flicker during framerate variations
  • Good anti-flicker algorithm for low frame rates (e.g. under 75fps). This may still create cons such as duplicate images but lesser evil versus letting it painfully flicker.

The name of the mathematic algorithm game (in firmware) is anti-flicker algorithms that keeps strobed VRR high quality while preventing flicker. This is very, very, very difficult to do, because games often have rather severe frame rate valleys.

Also, Low Frame Rate compensation (algorithm in FreeSync) can interfere with the quality of low-framerate strobed VRR, which is another algorithm that strobed VRR must fight against since these algorithms often operate independently (drivers handling LFC while monitor handles strobed VRR), which creates some flicker interactions that needs engineering.

For most people, I generally do not recommend strobed VRR on any monitor ever released unless (A) your game is almost guaranteed to run at least 60fps or 75fps and up permanently (VRR frame rates floating 60fps through 120fps from XBox Series). Good “beautiful” strobed VRR mandatorily requires frame rates above your flicker fusion threshold, otherwise it looks flickery like a 30Hz CRT or whatnot (worse than PAL flicker).

Future Strobed VRR is more recommended for the 75fps-165fps range
If your game can run at a frame rate range of 75fps-165fps (your 0.1% frametimes no slower than 1/85sec), then strobed VRR probably will look fine on the Eve Spectrum. But I also intend to provide an adjustable minimum-Hz anti-flicker threshold, so that single-strobed VRR works all the way down to PAL and NTSC framerates (50-60fps) for those who don’t mind the flicker of low strobed frame rates.

Technically, strobed VRR will work with any generic adaptive sync video source (FreeSync, VESA AdaptiveSync, HDMI VRR, G-SYNC Compatible), so should work with consoles. But I recommend PCs because of the high frame rate ranges required for high quality strobed VRR.

But as a hobbyist fan (above and beyond business of strobe tuning…) I love working on strobed technologies such as strobed VRR, and I’m fortunate to have hands-on work.

[/Commentary about Strobed VRR]

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