LG 32U990A early impression

I’ve had the LG for a couple of days now and wanted to share my impressions.

I will compare it against another 6k monitor, the Asus ProArt PA32QCV and the 5k Apple Studio Display XDR.

In addition to the LG, I have another 32” monitor on my desk, an older 4K Philips with a VA panel.

My main use case is text editing, coding and SDR video editing. Light gaming on the side.

I use the monitors in both Windows and MacOS. In Win, the 4K monitor is set to 150% scaling and the LG to 225% scaling.

On Windows, the improvements in text legibility of 6K over 4K are less than I expected. In Word and web browsers at my viewing distance the 4K already looks great and the 6K is a very modest improvement. In Teams, however, the 6K comes across as noticeably sharper. In WinExplorer the side folder view is again much cleaner on the 6K, but in the main window view both are excellent. The biggest difference I’ve noticed is Task Manager: on 4K it is visibly blurry whereas on the 6K it is perfectly sharp. I attribute this to inconsistent Windows rendering engines.

In MacOS the difference is far more noticeable. The 4K never looked great and the 6K is a major improvement in any app.

Surprisingly, the biggest improvement in image quality was in games. Civ7 looks way better in 6K than in 4K: aliasing pretty much becomes unnoticeable. The same in Victoria 3.

Compared to the 6K Asus, the LG has better viewing angles - but not as good as my old VA panel. The blacks are actually quite good and in a dark room not much behind the VA panel that was measured at 3500:1. However, with ambient light, the coating LG used results in a less darker black than my Philips. Speaking of the coating, I would rank it as medium coarse. The Asus was definitely better in this aspect. From my viewing distance it is OK, even on a purely white background. Obviously, the closer you sit the more distractive it becomes.

Wakeup time is very fast on the LG, whereas the Asus would take up 10s. Also, adjusting color modes is immediate on the LG, whereas it took upwards of 5s on the Asus.

I have the Mac connected via TB5 and my Windows PC via Display Port.

The default pixel response time looks better on the LG compared to the Asus. Even though the XDR is 120Hz and the LG 60Hz, motion clarity is not that much better to be honest. All of them are a far cry from an OLED.

The LG gets very bright in HDR, and is noticeably brighter than the ASUS, but highlights are a far cry from the XDR even if the overall full screen brightness does not feel that much behind.

On the Eizo monitor test, the LG looked more stable in the frequency patterns, whereas the ASUS exhibited strange temporal instability: visible flickering.

The Asus had a noticeable brightness fall off towards the left and right edges. The LG is much better in that regard. However there is some vertical banding non-uniformity: if I pan a photo of a bright sky sideways I can see it. Otherwise it is not noticeable.

Overall, I am quite satisfied with the LG, except the viewing angles which for a 32” screen should be better. It is most noticeable in the bottom right on Windows where the date and time are shown. Compared to the Philips VA it is visibly worse.

reddit.com
u/EindhovenFI — 4 days ago
▲ 2 r/HDR_Den+1 crossposts

Apple Studio Display XDR: Reproducible HDR video stutter on Mac Studio M4 Max, but not M1 mini

I’ve spent the last few days trying to isolate a reproducible HDR playback issue involving my Apple Studio Display and Mac Studio M4 Max. At first I thought it was an issue with an iPhone recording, but after a lot of testing I’m now convinced it’s something much more specific.

Symptoms
Random micro-stutters during playback of 4K HDR videos. It looks like a frame is held slightly too long, followed by a visible jump. With some HDR videos, I also see brief localized flashing on the XDR display (looks like the HDR/local dimming changes momentarily).

Test setup
Display
Apple Studio Display XDR (same monitor throughout)
Macs
Mac Studio M4 Max (stutters) - Tahoe 26.5.1
Mac mini M1 (plays smoothly) - Sequoia 15.3.2
Content tested
Multiple iPhone 4K60 HDR HEVC recordings
Multiple YouTube HDR videos

Results
Mac Studio M4 Max + Apple Studio Display XDR
❌ Random frame stutters on almost every HDR iPhone clip
❌ Same behavior with YouTube HDR
❌ Occasional localized HDR flashing
Mac mini M1 + Apple Studio Display XDR
✅ Same videos play smoothly
✅ No noticeable stuttering
Mac Studio M4 Max + different monitor
✅ YouTube HDR plays smoothly
✅ No obvious stutter

So the issue only appears with the combination of:
M4 Max
Apple Studio Display
HDR playback

What I investigated
Initially I suspected the iPhone recording itself.
I analyzed the original file using ffprobe and ffmpeg showinfo. I found:
Mostly constant 60 fps timestamps with only 21 tiny timestamp corrections (~1.67 ms over a 67-second clip).
I then:
Transcoded to H.264 using software (libx264)
Removed B-frames
Generated CFR versions
Verified there were no decoder frame drops in VLC
Performed frame-by-frame motion analysis using OpenCV phase correlation
The motion analysis did not reveal corresponding image-motion discontinuities that explain the visible frame holds.

Important to note that the original file also plays perfectly smoothly on both my iPhone and iPad.

Current conclusion
At this point I no longer think this is an issue with the iPhone recording itself. The evidence points much more strongly toward an issue somewhere in the HDR playback/rendering pipeline specific to the combination of the M4 Max and the Apple Studio Display. Whether that’s a macOS regression, a GPU/display engine issue, or something else in Apple’s HDR presentation path, I can’t say.
Has anyone else with an Apple Studio Display and an M4-series Mac noticed similar HDR playback stutter or flashing?

I also recorded a short demonstration documenting the stutter and flashing behavior if anyone is interested:

https://youtu.be/YPpk8Tdtxjo?is=DEye7zDsK7Ogyqwr

u/EindhovenFI — 2 months ago

Apple Studio Display XDR stuttering on iPhone footage

I recently got myself the Apple Studio Display XDR to go with my Mac Studio M4 Max.

However, very quickly I ran into a critical issue. I noticed that quite a few of my iPhone 4k60p videos would stutter, no matter what refresh rate I chose.

I made a short demo of the stuttering and flashing: https://youtu.be/YPpk8Tdtxjo?is=3hSllD\_nxMW3E3cJ

The videos playback just fine on my iPad (and iPhone).

Has anyone experienced something similar? I can’t at this point rule out an issue with MacOS video presentation itself.

youtu.be
u/EindhovenFI — 2 months ago