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Some quick info on specs.

http://www.viewsonicglobal.com/public/p ... G.pdf?pass

They dont really go into the PUREXP in the instruction manual. Just simple adjustments.

What does light to ultra mean? How does translate into strobing? Is it at any frequency?

witega wrote: ↑

06 Dec 2019, 11:59

The PureXP just has ON/OFF. A bit strange since the user manual has the 4 levels. Looks like ViewSonic probably preemptively included the 4 levels in the manual knowing its coming via firmware.

Correct. Expect it at beginning of 2020.

witega wrote: ↑

06 Dec 2019, 11:59

So get this. When you are in non-strobed mode you can select sRGB and then when you turn PureXP on, it looks like sRGB is still selected but the font turns black to where you cant select it. Weird.

My tests show that the XG270 manages to retain virtually its entire color gamut while strobed. You do need a colorimeter that is compatible with impulsed displays (the flickery displays like CRT, plasma, and pulsed backlights). It's quite difficult to have zero-crosstalk during strobing while using LCD full color gamut because there's no overdrive help for fullblacks and fullwhites, unless you have overdrive headroom below black, or overdrive headroom above white -- which is why some strobed monitors configure the LCD to use a smaller color gamut (i.e. LightBoost) to massively reduce strobe crosstalk. Fortunately the speed of a 240Hz IPS makes this unnecessary (at least at 120Hz refresh rate), which is fantastic.

Mike68 wrote: ↑

06 Dec 2019, 13:20

Some quick info on specs.

http://www.viewsonicglobal.com/public/p ... G.pdf?pass

They dont really go into the PUREXP in the instruction manual. Just simple adjustments.

What does light to ultra mean? How does translate into strobing? Is it at any frequency?

Simple answer:
It's simply a strobe length adjustment to let you choose how clear you want your motion to be.
There is a brightness versus clarity tradeoff effect. The user has the choice to choose.

Long Answer:
Many strobed monitors have variable persistence adjustments. A strobe length adjustment is a mandatory criteria for a Blur Busters Approved monitor. ULMB, DyAc, and a few others also have similar adjustments.

There is a brightness-versus-motion-clarity tradeoff effect, for ultra-fast panning motion, like DOTA2 panning, LOL panning, browser smoothscrolls, FPS turning, map panning, especially motionspeeds that are at your limits of eye-tracking speed.

Blur Busters Law means 1ms of pulse length translates to 1 pixel of motion blur per 1000 pixels/second. If you adjust to ~0.5 millisecond pulse length, you get only 1 pixel of motion blur per 2000 pixels/sec panning motion and can thus read the street name labels on the Panning Map Test. At 3000 pixels/sec
- Test is hopeless blurry mess at 60 Hz
- Still blurry at 240 Hz non-strobed
- Barely readable at default ULMB
- fully readable like a CRT tube if readjust ULMB Pulse Width down to lower settings (e.g. 0.5ms).
PureXP+ at the "Ultra" setting passes the TestUFO Panning Map Test. On the first unit, it's like an Ultra setting out of the box, but it can be fairly dark for bright rooms. I usually play at Normal during daylight and either Extreme/Ultra at night when my room is a cave.

For more information, see advanced articles:
Frequently Asked Questions About Pixel Response: GtG Versus MPRT
Blur Busters Law And The Amazing Journey To Future 1000 Hz Displays

Chief Blur Buster wrote: ↑

06 Dec 2019, 14:08

Simple answer:
It's simply a strobe length adjustment to let you choose how clear you want your motion to be. There is a brightness versus clarity tradeoff effect. The user has the choice to choose.

Awesome sounds like the old BenQ Utility program built right into the OSD.

witega wrote: ↑

06 Dec 2019, 14:26

Awesome sounds like the old BenQ Utility program built right into the OSD.

Yes -- Quick access convenience. Rapid switching between PureXP brightness-vs-clarity.

In the new firmware, I use Ultra during night, and Normal during daytime.

So Chief is PureXP set to "Ultra" the only option one has for CRT readibility with that Panning Map test? Does G-Sync, even with ultra low latency enabled, still has more blur?

witega wrote: ↑

06 Dec 2019, 14:39

So Chief is PureXP set to "Ultra" the only option one has for CRT readibility with that Panning Map test?

The answer is murky because different CRTs have different phosphor decay speeds, and CRT phosphor is a sawtooth pulse graph (rapid rise, sharp peak, slow fall), while strobing is essentially square wave (rapid ride, flat top, rapid fall). All settings are much closer to CRT than default. The differences are very subtle and unnoticeable at slow panning speeds, and the differences between PureXP settings more easily reveal itself at fast panning speeds (like 1 screenwidth per second or faster).

witega wrote: ↑

06 Dec 2019, 14:39

Does G-Sync, even with ultra low latency enabled, still has more blur?

VRR non-strobed produces display motion blur directly proportional to frametime, according to Blur Busters Law

Here are two charts that will help explain things better:

For strobed, (including PureXP)

While this is slower motion speeds though (960 pixels per second standardization), and doesn't include <1ms, but it does help demonstrate some concepts. Double the motion speed, you double the blur trail length, and then it becomes easier to see differences at lower persistence at faster motion speeds.



For non-strobed (including variable refresh)



Since 240Hz is the maximum Hz, you are bottlenecked to no less than 1/240sec = ~4ms persistence for non-strobed VRR.
That does not include GtG, which can produce additional motion blur above-and-beyond Blur Busters Law of 1ms = 1 pixel blur per 1000pix/sec motion.

For PureXP (new firmware), the PureXP="Light" setting is roughly ~2.8ms persistence at 144Hz, while PureXP="Ultra" is closer to ~0.7ms persistence at 144Hz. This technically falls to ~1.7ms persistence at 240Hz for PureXP="Light", and ~0.4ms persistence for PureXP="Ultra" (That's at the PWM switching level. Real life measurements will vary a bit from this, since white backlight LEDs have phosphor, and there's a very tiny sub-millisecond phosphor decay associated with that) but that doesn't account for strobe crosstalk which can begin to interfere with MPRT/persistence measurements once crosstalk raises above 10%.

Roughly, the pulse lengths of PureXP in the latest firmware:
Light = 4/10th refresh cycle strobe length
Normal = 3/10th refresh cycle strobe length
Extreme = 2/10th refresh cycle strobe length
Ultra = 1/10th refresh cycle strobe length

Right now, current monitors are shipping using an ON setting close to "Ultra" setting by default . So it's like OFF/Ultra in the first firmware, while the new firmware are OFF/Ultra/Extreme/Normal/Light. So you're getting brighter settings with just a smidgen more blurring.

Thanks Chief for the detailed reply. Much appreciated. Sorry for the basic questions, I need to read more of the articles on Blur Busters.

0.7ms @ 144hz that is amazing!

Again just wanted to thank you for how much time and effort you put into your replies to my questions. I am super glad that companies like ViewSonic are reaching out to Blur Busters to have their blur reduction tuned.

I can't wait until we can see FRAT implemented with 1000hz and 1000FPS. That's the dream!

And whats the range of blur reduction? Does it do 60 single strobbed?

Mike68 wrote: ↑

06 Dec 2019, 15:17

And whats the range of blur reduction? Does it do 60 single strobbed?

Answered in this post as a single-strobe 75Hz through 240Hz strobe range, with a crosstalk-clean range of 75Hz through 144Hz(ish).

Strobe crosstalk is a side effect of law of physics of "cramming-GtG-into-VBI". Crosstalk-free strobing requires GtG fast enough to be compressed into the vertical blanking interval between refresh cycle scanouts. Higher refresh rates are prone to crosstalk and double images. Lower Hz makes it (A) easier to hide GtG in dark between less frequent strobe flashes; and (B) easier for GPU to match framerate with Hz. This then gives you the proper CRT clarity experience. Currently, no 240 Hz monitor on the market is crosstalk-free at max refresh rate 240 Hz. What is impressive is that the new 240Hz 1ms NanoIPS panels performs well into the ballpark of TN monitor performance.

The good news is this monitor is also software BFI friendly. The software BFI workaround for 60Hz strobing exists -- for 60 Hz on this monitor is so good, that it looks indistinguishable from hardware-strobe 60Hz. So you can use MAME emulator at 120Hz PureXP, enable its software BFI, and it looks like really good 60Hz hardware strobing.

I think this would be a kick-ass LCD for MAME arcade cabinets requiring a low-persistence LCD. Yes, 240Hz overkill, but that's the price you pay for good low-Hz CRT-like strobing. I would recommend the latest firmware (early 2020) with PureXP="Light" for 60Hz strobing (120Hz PureXP + software BFI combo), to improve strobed brightness.

witega wrote: ↑

05 Dec 2019, 23:45

Yeah 120hz strobed is incredible with this monitor. I am not seeing any crosstalk, just remarkable. With the color accuracy of an IPS, it's time to retire the Sony FW900 (well I already did, but if I still had it).

That's quite the testimonial!

Right now, used FW900 CRTs are priced at several thousand dollars, partially thanks to DigitalFoundry and Vice. And shipping costing several hundred...

I love CRTs as much as the next person, but Blur Busters is striving to keep improving LCDs to try to match ever closer and closer to CRTs. The XG270 is much cheaper, easier to carry and ship, and has other benefits like tack-sharp 1080p. Sure, you have to throttle back the Hertz a bit to make the crosstalk disappear, but even the FW900 barely does 120Hz at 1080p.

I have a FW900 CRT loan offer. I might head-head XG270 versus FW900 in early 2020 because I feel the XG270 wins in most categories except absolute-blacks.

For most people, I feel that is no longer enough to compensate for the XG270 winning categories, now that the crosstalk-free strobe color problem is finally solvable with 240Hz 1ms IPS panels.