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Brightness and Contrast

To read about our monitor tests in-depth, please check out Display Testing Explained: How We Test PC Monitors. We cover brightness and contrast testing on page two.

Uncalibrated – Maximum Backlight Level

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Asus ROG Swift PG42UQ — (Image credit: Tom's Hardware)

If you need a super-bright monitor, OLED is not the tech for you. The PG42UQ is on par with its competition at just over 350 nits for SDR. This was determined by measuring a 25% window pattern. A full field pattern returned around 190 nits. If you turn on the Uniform Brightness option, windows and fields will measure the same, about 190 nits peak. The AW5520QF is an early-generation product and cannot muster the light output of newer panels. The XG43UQ’s VA panel is the obvious choice for those needing a light cannon in their office.

All four OLEDs have unmeasurable black levels and, therefore, infinite contrast. I’ve formatted the charts to reflect this. The G8 uses an always-active zone-dimming Mini LED backlight to achieve over 24,000:1 contrast which is impressive. The XG43UQ’s result is in the panel’s native state with no dynamic contrast in play.

After Calibration to 200 nits

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I set the PG42UQ to 200 nits with a window pattern to level the playing field for the calibrated comparison. In practice, I leave its brightness slider maxed because the picture is never too bright. Black levels remain impossible to measure.

The ANSI test yields the same results though the G8’s value is cut in half. It’s still an incredible monitor among LCDs and can deliver over 2,000 nits in HDR mode. But it still won’t have the look of an OLED. Their contrast and black levels are something that no LCD can match.

MORE: Best Gaming Monitors

MORE: How We Test PC Monitors

MORE: How to Buy a PC Monitor: A 2022 Guide

MORE: How to Choose the Best HDR Monitor

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Christian Eberle is a Contributing Editor for Tom's Hardware US. He's a veteran reviewer of A/V equipment, specializing in monitors.

15 Comments Comment from the forums

oofdragon

"One obstacle to wide acceptance has been size. Early OLED computer monitors weren’t much smaller than big-screen TVs". Article about 42 inch "PC monitor". Fail
Reply
JarredWaltonGPU

oofdragon said:
"One obstacle to wide acceptance has been size. Early OLED computer monitors weren’t much smaller than big-screen TVs". Article about 42 inch "PC monitor". Fail
42 inches for 4K on a monitor seems about ideal to me! I felt 30-inch for 1440p was a good size, so if you want to increase the resolution by 125% (1.5X in each dimension), you definitely need to make the screens bigger. This 4K in a 14-inch laptop business is ludicrous, and 4K in a 28-inch monitor isn't much better for practical use.
Reply
Greg7579

Admin said:
Asus adds a 42-inch 4K model to the list of available OLED gaming monitors. The ROG Swift PG42UQ sports a 138 Hz refresh rate, Adaptive-Sync, HDR and extended color. It delivers a stunning image and premium gaming performance.

Asus ROG Swift PG42UQ 4K OLED Review: Stunning in Every Respect : Read more
I am a photographer and shoot high-res GFX 100 (100 MP) files. For years I have used an ASUS 32 inch IPS professional monitor that cost me several thousand 5 years ago. I don't render or edit video, and I don't game. I just edit and enjoy my high-res image files and use Photoshop and mostly Lightroom. The color gamut is important to me, but this monitor seems to be right there at the professional level for photography work, and the 42 inch size (up from 32) I think I would relish.

So, should I get this monitor if I never game? I build my own high-end desktop and am about to build a rig with the 4090 just for the Hell of it.

What do I lose when compared to the ASUS pro mini-led monitor that costs 5 grand?

I think I'm going to get this monitor for my photography work and enjoyment.

What do you think? Or is ASUS about to come out with a new "Pro" monitor that is cheaper and better than their current lineup?

I don't need 144 Hz, but why not? Maybe I will even try a game or two.
Reply
hancor

Greg7579 said:
I am a photographer and shoot high-res GFX 100 (100 MP) files. For years I have used an ASUS 32 inch IPS professional monitor that cost me several thousand 5 years ago. I don't render or edit video, and I don't game. I just edit and enjoy my high-res image files and use Photoshop and mostly Lightroom. The color gamut is important to me, but this monitor seems to be right there at the professional level for photography work, and the 42 inch size (up from 32) I think I would relish.

So, should I get this monitor if I never game? I build my own high-end desktop and am about to build a rig with the 4090 just for the Hell of it.

What do I lose when compared to the ASUS pro mini-led monitor that costs 5 grand?

I think I'm going to get this monitor for my photography work and enjoyment.

What do you think? Or is ASUS about to come out with a new "Pro" monitor that is cheaper and better than their current lineup?

I don't need 144 Hz, but why not? Maybe I will even try a game or two.

I bought this unit about 2 months ago, and the firmware issue is now resolved. This monitor is everything state of the art, for gaming, photography, or plain old work, net surfing. Currently, paired with my EVGA 2080 Ti, while the EVGA FTW3 RTX Ultra Gaming, is being repaired. Colors just "pop" compared to TN, VA, or IPS panels.
Without question you will enjoy this monitor immensely. Cheers :)
Reply
eisenb11

I have this monitor and it’s great - but I can’t believe that the article didn’t mention fringing on text. IMHO that’s the biggest issue (although you can live with it) with this monitor.

The author is minimizing it by using 150% scaling. He really should have also tested the monitor at 100% scaling so you can, you know, use the full 4K res of the monitor for your desktop.

This is an inherent problem of the WRGB sub pixel layout which pretty much all LG panels use. The real fix is that enough people need to complain about it (not work around it with higher scaling) so Microsoft updates ClearType which is currently optimized for normal RGB.

For those with this monitor, using MacType helps a bit, but a real fix to ClearType is really needed. It improves text quality, but it’s still nowhere near LCD level. You can turn off ClearType, but text looks terrible - even at 4K resolution so that it’s still better looking with the fringing.
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PlaneInTheSky

Even the best Mini LED panels can’t reproduce intra-image black levels like an OLED.

Yep, my OLED has far better local dimming than the Mini LCD TV and none of the light bleeding. Each Mini LED backlight still illuminates thousands of pixels, so Mini LED still suffers from the same problems of IPS, TN and VA panels, light bleeding, no true black, viewing angle problems, etc.

The light bleeding which causes blooming, is less of an issue on TV consuming movies for example. But it is a real issue for text for example.

Only OLED and E-ink solves this problem.

(The exception is of course the QD-OLED garbage from Samsung and Alienware, which messes it all up with their color artefacts.)

The big promise was that Micro LED would solve Mini LED's problems and have per pixel dimming. But Micro LED is turning out to be a manufacturing nightmare. The tiny circuitry needed to power millions of LED is a mess and yields are terrible.
Reply
PlaneInTheSky

I have this monitor and it’s great - but I can’t believe that the article didn’t mention fringing on text. IMHO that’s the biggest issue (although you can live with it) with this monitor.

The Alienware and Samsung QD-OLED have this problem. Color artefacts, color fringes. Whatever people want to call it. They're red and green lines surrounding high contrast elements due to a difference in pixel layout.

I am spared from this problem on my regular OLED TV which I use as a monitor.
Reply
PlaneInTheSky

This is an inherent problem of the WRGB sub pixel layout which pretty much all LG panels use.

LG sells OLED monitors with an RGB layout that has no color fringing, like the LG Ultrafine Pro series.

Of course, they're more expensive than the OLED screens found in gaming monitors.
Reply
Blacksad999

Interesting review. Every other monitor testing site and reviewer suggested that "Cinema Mode" is the best setting for accurate colors. I'm also curious which firmware the reviewer is using, as people all over the place are dealing with washed out non-functional HDR on firmware V033. All of the previous firmware versions don't allow the panel to wake on sleep if you're using "overclocking" to reach 138hz, and the pixel refresh pop up returns very commonly, so I was surprised to see no mention of any of that.
You can read about the broken HDR in depth on Rtings review of the monitor. The tone mapping is broken on this monitor, and only covers 34% of the gamut when HDR is on, as you can see here: https://www.rtings.com/assets/pages/ncyZeV4m/fall-800-hdr-off-large.jpgIf anyone knows which firmware the reviewer is using, let me know. I don't think it's the updated version V033.
Reply
DougMcC

So close to the monitor i'm dying to buy. Just get me to 144hz and no bigger than 37".
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