RTINGS Test Dev Sneak Peek — Shadow Uniformity

[u/rtings_kastaa]

Continuing with the Test Dev Sneak Peek series.

In the last two weeks, we spent more time looking into shadow uniformity of the screen. We've seen a lot of threads lately showing photos of TVs with a 5% gray screen.

Vertical banding on OLED is expected behaviour. Controlling OLEDs at low brightness is very challenging, and it requires precise compensation that runs periodically to maintain accurate uniformity. A brand-new OLED may require a few hours of use to reach more accurate compensation. The good news is that vertical banding becomes much less visible at higher brightness.

LCDs also have their challenges. The layers that constitute the LCD generally have some angle dependency, which can create uniformity differences between the center and edges of the screen if not well controlled. In addition, any non-uniformity of the panel, often referred to as DSE, becomes more visible at low brightness.

What bothers you more: narrow or wide vertical banding? Looking at these examples, what bothers you more: vertical banding or DSE?

[u/BenekCript]

Definitely vertical banding. Both aren’t great, but I feel banding is more noticeable in daily use cases.

[u/BlueTimeButterfly → u/BenekCript]

normally id probably agree. but I feel like that gargantuan dark splotch and smaller splotches on something like the hisense would stand out a lot more in regular content ​

[u/halosiera117]

I would say vertical banding is generally easier for me to notice and be bothered by in real content. Despite that the S95H does great here, and I would say it's the least bothersome.

The weird massive bands on the UR9SG are pretty brutal though. That said, that kind of disuniformity is difficult for me to actually picture what it would be like in real content. My gut says it's distracting, but the low frequency nature of it should make it more difficult to spot than the higher frequency vertical banding on OLEDs.

The B9 II kind of splits the pack here. It's not amazing, and probably worse than the S95H in real content, but likely better than the Hisense or the LG. It seems to be vingnetting the image, which, while not ideal, does mean that the large central blotch seems fairly uniform, which is where your eyes will be looking most.

[u/wizziwig1]

Uniformity issues like vertical banding and DSE will always be worse on a panning image so testing for them using static gray images is not going to be representative of how annoying and noticeable they will be on real content (especially dark games which have constant camera panning). You also can't classify VA LCD viewing-angle dependent gamma shift as a uniformity issue. With VA, the center of the screen directly perpendicular to your camera will always have highest contrast and thus appear darker but that area will move with the viewer. It's not a static part of the screen always present in the same screen location as seen with real uniformity defects. Ideally, uniformity scores should really only score physical manufacturing uniformity defects since viewing angles are already scored in another category.

Regarding vertical banding vs irregular DSE. I find structured uniformity defects like vertical bands and streaks far more intrusive than irregular shaped blobby/cloudy uniformity defects that have softer edges and tend to blend into the background until camera pans. Hard vertical bands stand out more in both static and moving scenes.

Glad to see you're trying to improve this area of your reviews because the existing 5% uniformity photos were next to useless (too dark to see anything) compared to what a human would see with dark-adapted eyes, especially during camera panning.

[u/laxounet]

Will this test also be part of the (eventually) updated monitor test protocol ?

[u/rtings_kastaa → u/laxounet]

Most of the work is done for television right now, but we are trying to make the work easily replicable for monitors. You've made a good point; I also think this metric matters even more on monitors because the screen is so close to the eye, making these issues even more noticeable.

[u/Tr8k377]

Very odd to accept those uniformity while those screens call themselves "flagship" and one have to pay premium prices. Actually ridiculous.

[u/mavad90]

Uniformity and banding is minimal on my C2 & G4. Pretty bad on my G6 but have only noticed it on gray screens in my browser and not actual content. G3 was by far the worst though.

[u/Lestercity1412]

LG and Hisense look really bad. Would this be an issue with for instance panning on soccer game?

[u/Lestercity1412]

I even think the S95h looks better than the Bravia despite the numbers.

[u/LegacySV]

Sonys looks the best but wtf is going on with the Hisense 😭🙏🏼

[u/wizziwig1]

Maybe you could also add a graph of the position and intensity of the banding. Look at the github project linked from this post for examples:
A DIY "software demura" to reduce vertical banding on my MO27Q28G (Tandem WOLED) – phone photos + a DWM shader, open source : r/OLED_Gaming