BenQ Strobe Calibration & Input Lag Gradient Behaviours

Adjusting BENQ Blur Reduction and DyAc (Dynamic Acceleration) including Blur Busters Strobe Utility. Supports most BenQ/Zowie Z-Series monitors (XL2411, XL2420, XL2720, XL2735, XL2540, XL2546)
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Bandaidsrmyjob
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BenQ Strobe Calibration & Input Lag Gradient Behaviours

Post by Bandaidsrmyjob » 10 Mar 2020, 12:08

In the service menu of the xl2546 what do the options "intensity" and "Area relate to? I played with either setting with dyac off and on. I seen that with dyac on "intensity" must act like ULMB as the brightness of the display decreased with higher numbers up to max of 25. Area however goes from 1-100 without any noticeable change.

I found the service menu by researching for a new display ironically (I want a bright display but with fast refresh as dyac/ULMB makes the image to dark). I then began messing with service menu settings which may or may not have caused the display to entirely reset as the buzzer setting keeps becoming activated along with picture mode changing to FPS1 instead of standard. I didn't think these were major settings.

Falkentyne
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Re: BenQ service menu options

Post by Falkentyne » 11 Mar 2020, 00:45

Bandaidsrmyjob wrote:
10 Mar 2020, 12:08
In the service menu of the xl2546 what do the options "intensity" and "Area relate to? I played with either setting with dyac off and on. I seen that with dyac on "intensity" must act like ULMB as the brightness of the display decreased with higher numbers up to max of 25. Area however goes from 1-100 without any noticeable change.

I found the service menu by researching for a new display ironically (I want a bright display but with fast refresh as dyac/ULMB makes the image to dark). I then began messing with service menu settings which may or may not have caused the display to entirely reset as the buzzer setting keeps becoming activated along with picture mode changing to FPS1 instead of standard. I didn't think these were major settings.
Intensity=Strobe Duty. This is what it was called in the original Z series monitors. This controls the "duration of the "off" cycle with respect to the "on" cycle of the backlight during a strobe (the backlight must turn on and off once during a refresh cycle, e.g. every 8.3ms at 120hz, or once per frame at 120 FPS at 120hz, for example). The off cycle is ALWAYS much much longer than the on cycle. The longer the off cycle, the dimmer the image and the clearer the blur reduction effect.

Area is hard to explain, but this was called Strobe Phase in the older Z monitors. This is basically at what 'point' during a frame (what point during that 8.3ms interval) that the strobe begins and ends. The point where it begins and ends will have a horrific double image effect of two frames getting superimposed on each other. I explained this in more detail in the sticky, if you want to read it. The part "above" the worst part of the crosstalk is basically the previous frame (or in other words, the frame that was rendered earlier--you can actually say that is up to 1 frame of improved input lag). You can tell by looking at "Test UFO, Alien Invasion" and you will see that the frame seems to move to the "Right" above the crosstalk main boundary, and since the picture is moving left to right, it's basically like 1 frame of "improved" latency (UP to 1 frame). The part "below" the crosstalk is the "next" frame--so you will see it to the LEFT <--, which is up to 1 frame worse input lag. You can adjust this boundary to change where it appears, so it doesn't cause distractions in games.

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Re: BenQ service menu options

Post by Chief Blur Buster » 11 Mar 2020, 21:17

Falkentyne wrote:
11 Mar 2020, 00:45
The part "above" the worst part of the crosstalk is basically the previous frame (or in other words, the frame that was rendered earlier--you can actually say that is up to 1 frame of improved input lag).
You got your description almost perfect! :) Except it is the opposite word -- below, not above.

It is the area BELOW the crosstalk band that is laggier.

The area above the crosstalk-band is AHEAD of the area below the crosstalk-band.

Watch the high speed video tests show that panels will refresh the top part of the screen surface before the bottom part. These are high speed videos of TestUFO scanout at www.testufo.com/scanout which flips between 4 images rapidly, 1 image per refresh cycle.

phpBB [video]


See the frame numbers? They're fresher at the top edge of the screen.

TL;DR: Top edge is ALWAYS refreshed first before bottom edge!

The top edge of the screen is above the crosstalk band, and thus lower lag. Conceptually, the strobe backlight (flash) is sort of like a flash photograph mid-scanout -- freezing the visibility of the panel's current GtG pixel transition state -- the crosstalk bar is where the GtG pixel transitions are still in middle of transition. Because of this, the common classic Leo Bodnar Lag Tester lag gradient (TOP < CENTER < BOTTOM) does not apply here.

Quality wise, you want GtG to be between refresh cycles, but some people want lower lag for screen centre, so moving the crosstalk bar upwards to right below the crosshairs, reducing the lag of screen centre during strobed operation.
Bandaidsrmyjob wrote:
10 Mar 2020, 12:08
In the service menu of the xl2546 what do the options "intensity" and "Area relate to? I played with either setting with dyac off and on. I seen that with dyac on "intensity" must act like ULMB as the brightness of the display decreased with higher numbers up to max of 25. Area however goes from 1-100 without any noticeable change.
You MUST view a motion test while adjusting. While viewing www.testufo.com/crosstalk --

That's why downloading Blur Busters Strobe Utility is easier than the service menu, it has that TestUFO test built-in into the executable application!

Adjusting "Area" or "Strobe Phase" looks like this:

Image

From ANIMATIONS: Adjusting strobe phase / crosstalk

These are example of different user preference (quality priority --versus -- latency priority)

Image

During VSYNC OFF, strobing creates an inverted latency gradient (relative to non-strobed VSYNC ON)

VSYNC ON, nonstrobed creates TOP < CENTER < BOTTOM lag
VSYNC ON, strobed creates TOP = CENTER = BOTTOM lag
VSYNC OFF, nonstrobed creates TOP = CENTER = BOTTOM lag
VSYNC OFF, strobed creates TOP > CENTER > BOTTOM lag
Assuming perfect strobe phase centered in VBI.
Run 100 lag measurements averaged, will create these very interesting input-lag gradients along the screen's vertical dimension!

But if you adjust strobe phase to move the crosstalk bar, the latency gradent changes so TOP-vs-CENTER-vs-BOTTOM is in different ordering of input lag, as according to the following chart:

Image

So you've divided the latency gradients according to the crosstalk bar location!

TL:DR: Lowest input lag is always in the screen panel area immediately above the crosstalk band.
Head of Blur Busters - BlurBusters.com | TestUFO.com | Follow @BlurBusters on Twitter

       To support Blur Busters:
       • Official List of Best Gaming Monitors
       • List of G-SYNC Monitors
       • List of FreeSync Monitors
       • List of Ultrawide Monitors

Falkentyne
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Joined: 26 Mar 2014, 07:23

Re: BenQ service menu options

Post by Falkentyne » 12 Mar 2020, 14:48

Chief Blur Buster wrote:
11 Mar 2020, 21:17
Falkentyne wrote:
11 Mar 2020, 00:45
The part "above" the worst part of the crosstalk is basically the previous frame (or in other words, the frame that was rendered earlier--you can actually say that is up to 1 frame of improved input lag).
You got your description almost perfect! :) Except it is the opposite word -- below, not above.

It is the area BELOW the crosstalk band that is laggier.

The area above the crosstalk-band is AHEAD of the area below the crosstalk-band.

Watch the high speed video tests show that panels will refresh the top part of the screen surface before the bottom part. These are high speed videos of TestUFO scanout at www.testufo.com/scanout which flips between 4 images rapidly, 1 image per refresh cycle.

phpBB [video]


See the frame numbers? They're fresher at the top edge of the screen.

TL;DR: Top edge is ALWAYS refreshed first before bottom edge!

The top edge of the screen is above the crosstalk band, and thus lower lag. Conceptually, the strobe backlight (flash) is sort of like a flash photograph mid-scanout -- freezing the visibility of the panel's current GtG pixel transition state -- the crosstalk bar is where the GtG pixel transitions are still in middle of transition. Because of this, the common classic Leo Bodnar Lag Tester lag gradient (TOP < CENTER < BOTTOM) does not apply here.

Quality wise, you want GtG to be between refresh cycles, but some people want lower lag for screen centre, so moving the crosstalk bar upwards to right below the crosshairs, reducing the lag of screen centre during strobed operation.
Bandaidsrmyjob wrote:
10 Mar 2020, 12:08
In the service menu of the xl2546 what do the options "intensity" and "Area relate to? I played with either setting with dyac off and on. I seen that with dyac on "intensity" must act like ULMB as the brightness of the display decreased with higher numbers up to max of 25. Area however goes from 1-100 without any noticeable change.
You MUST view a motion test while adjusting. While viewing www.testufo.com/crosstalk --

That's why downloading Blur Busters Strobe Utility is easier than the service menu, it has that TestUFO test built-in into the executable application!

Adjusting "Area" or "Strobe Phase" looks like this:

Image

From ANIMATIONS: Adjusting strobe phase / crosstalk

These are example of different user preference (quality priority --versus -- latency priority)

Image

During VSYNC OFF, strobing creates an inverted latency gradient (relative to non-strobed VSYNC ON)

VSYNC ON, nonstrobed creates TOP < CENTER < BOTTOM lag
VSYNC ON, strobed creates TOP = CENTER = BOTTOM lag
VSYNC OFF, nonstrobed creates TOP = CENTER = BOTTOM lag
VSYNC OFF, strobed creates TOP > CENTER > BOTTOM lag
Assuming perfect strobe phase centered in VBI.
Run 100 lag measurements averaged, will create these very interesting input-lag gradients along the screen's vertical dimension!

But if you adjust strobe phase to move the crosstalk bar, the latency gradent changes so TOP-vs-CENTER-vs-BOTTOM is in different ordering of input lag, as according to the following chart:

Image

So you've divided the latency gradients according to the crosstalk bar location!

TL:DR: Lowest input lag is always in the screen panel area immediately above the crosstalk band.
Thank you Chief. I always get mixed up by this stuff.

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Re: BenQ service menu options

Post by Chief Blur Buster » 12 Mar 2020, 15:52

Falkentyne wrote:
12 Mar 2020, 14:48
Thank you Chief. I always get mixed up by this stuff.
Your description was much better this time -- just wanted to correct which side of the crosstalk-line has lowest lag.
Appreciate you chiming in!
Head of Blur Busters - BlurBusters.com | TestUFO.com | Follow @BlurBusters on Twitter

       To support Blur Busters:
       • Official List of Best Gaming Monitors
       • List of G-SYNC Monitors
       • List of FreeSync Monitors
       • List of Ultrawide Monitors

Bandaidsrmyjob
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Joined: 10 Mar 2020, 12:01

Re: BenQ service menu options

Post by Bandaidsrmyjob » 21 Mar 2020, 02:03

Wow. Informative beyond what I expected.

Thank you for your time. ;)

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Chief Blur Buster
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BenQ Strobe Calibration & Input Lag Gradient Behaviours

Post by Chief Blur Buster » 24 Mar 2020, 23:26

Bandaidsrmyjob wrote:
21 Mar 2020, 02:03
Wow. Informative beyond what I expected.

Thank you for your time. ;)
You are welcome!
Head of Blur Busters - BlurBusters.com | TestUFO.com | Follow @BlurBusters on Twitter

       To support Blur Busters:
       • Official List of Best Gaming Monitors
       • List of G-SYNC Monitors
       • List of FreeSync Monitors
       • List of Ultrawide Monitors

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