240hz contrast trick

[240hz]

So I just got this monitor and I discovered something very nice. There use to be a contrast trick for BenQ gaming monitors, where if you lowered the contrast, it helped hide a tiny bit of ghosting on the low overdrive. Through some testing, I discovered this same trick also works on Dell monitors (s24 165hz and the aw25 240hz), even on overclocked overdrive settings, but worked a lot better compared to BenQ. I posted about this on OCN, but I will post here so you don't have to jump there.

With the Dell S2417dg, if you lowered the contrast, you could see how much it improved the ghosting:

Dell S24 @ 165hz with Response Time FAST, Contast 75, Brightness 75
Dell S24 @ 165hz with Response Time FAST, Contrast 0, Brightness 100

As you can see, dropping the contrast to 0 makes the ghosting nearly disappear and it makes using the overclocked setting much nicer. The only real downside, was that the colors were pretty bad doing this trick.

Well, I recently got the aw25 240hz panel and discovered the trick also works, but much better. The aw25 has 2 overclocked settings, fast and superfast. With this monitor on superfast and contrast trick, the motion is incredibly clean and sharp, it's really amazing. It almost looks like I'm using ULMB, it's that good. This trick paired with G-Sync = butter.

Here is how to achieve this trick on the aw25:

Select the FPS color profile from the OSD (not required)
Make sure 240hz is enabled.
Set response time to SuperFast on the OSD.
Turn dark stabilizer up to 3 on the OSD.
Set contrast to <20% and brightness to 100% on the OSD.
Use the low input-lag guide for VRR (V-Sync on in NVCP, V-Sync off in-game, and cap fps at 235).
Test in a game where you can hold a stable 240fps (Overwatch, CSGO, etc), or testufo.com

In theory, this should work on every 240hz monitor, as they all use the same panel. The only issue, is that you might not have as clean motion, as a Russlan review (down at the moment, cache here) site had reviewed a bunch of 240hz panels and they deemed the Alienware was better when it came to overdrive and overclocked overdrive. They also gave it the edge on having better colors.

[RealNC]

This seems to be working on a gsync IPS too (XG2703-GS). This provides a benefit when using ULMB. But apparent brightness is lost, which especially for ULMB is a big drawback. However, there's still some brightness headroom left if you're willing to run brightness 100.

In non-ULMB mode, lowering contrast to 15 and upping brightness to 40 or so to compensate seems to improve apparent pixel response by quite a lot. The character of the image changes though; the colors are probably off.

I think this is the reason why this monitor automatically lowers contrast to 45 when enabling ULMB. It was a mystery to me why it does that, but I think this is it. Lowering contrast seems to improve apparent pixel response and thus lowers crosstalk.

[240hz]

This seems to be working on a gsync IPS too (XG2703-GS). This provides a benefit when using ULMB. But apparent brightness is lost, which especially for ULMB is a big drawback. However, there's still some brightness headroom left if you're willing to run brightness 100.

In non-ULMB mode, lowering contrast to 15 and upping brightness to 40 or so to compensate seems to improve apparent pixel response by quite a lot. The character of the image changes though; the colors are probably off.

I think this is the reason why this monitor automatically lowers contrast to 45 when enabling ULMB. It was a mystery to me why it does that, but I think this is it. Lowering contrast seems to improve apparent pixel response and thus lowers crosstalk.

Oh, nice. I did not expect it to work on other monitors, let alone an IPS panel.

I just tried with 144hz blur reduction + contrast trick, but it's just not as good as 240hz + contrast trick. I think the overdrive toggle gets reset to normal when using ULMB, as the response time settings get greyed out once ULMB is enabled. As crazy as it sounds, 240hz + contrast trick looks better to me than 144hz ULMB + contrast trick, especially considering G-Sync also stays enabled with 240hz.

[Chief Blur Buster]

Yup, reducing contrast slightly makes a big difference in ULMB strobe crosstalk.

This improves the overdrive overshoot voltage headroom/legroom (below-black and above-white) making more quickly & more effective GtG pixel transitions that reach closer to their final color values by the time the strobe backlight flashes.

[7bhsq]

I tried this tweak on the PG258Q. When using "Extreme" overdrive, just the contrast adjustment alone makes the overshoot so much less ugly that I consider this mode usable now. Thanks for the tip.

[hammelgammler]

Does the PG258Q achieve the same clarity as the Alienware AW58 with the contrast trick? Because I'm almost convinced to go from 1440p 165Hz to 1080p 240Hz if it's near 144Hz ULMB clarity + G-Sync.

[RealNC]

Does the PG258Q achieve the same clarity as the Alienware AW58 with the contrast trick? Because I'm almost convinced to go from 1440p 165Hz to 1080p 240Hz if it's near 144Hz ULMB clarity + G-Sync.

No. You will never be able to achieve ULMB clarity even if the pixel response time was 0ms (meaning infinitely fast pixels.) You will always have 7ms of blur at 144FPS/144Hz and 4ms of blur at 240FPS/240Hz.

To get the same clarity as 120Hz ULMB without ULMB, you need something like 1000FPS/1000Hz, which of course doesn't exist.

[Chief Blur Buster]

To get the same clarity as 120Hz ULMB without ULMB, you need something like 1000FPS/1000Hz, which of course doesn't exist.

[Chief Blur Buster]

Does the PG258Q achieve the same clarity as the Alienware AW58 with the contrast trick? Because I'm almost convinced to go from 1440p 165Hz to 1080p 240Hz if it's near 144Hz ULMB clarity + G-Sync.

1080p 240Hz translates to about 4ms peristence, so it has approximately 2-4x the motion blur of ULMB (depending on whether it's a 1ms or 2ms strobed implementation).

Persistence of non-ULMB = One refresh cycle
Persistence of ULMB = Strobe flash length (adjustable via "ULMB Pulse Width")

And Blur Buster's Law:
"1ms of persistence translates to 1 pixel of motion blurring at 1000 pixels/second motion"

So the simple math means 2ms persistence at 3000 pixels/sec = (3000pixels/sec * 0.002sec) = 6 pixels of motion blur.

[crossjeremiah]

240hz + Gsync + 100 brightness + 20 contrast. AW2518h feels amazing, hardly any ghosting on super fast overdrive. I did 0 contrast for a bit and I noticed it was way too dark