OLED “microsecond response time” / “infinite contrast” claims vs reality?

[DrBalanced]

This post is about 2 related topics that have been bothering me for a while and I can’t find any good discussion online.

OLED panels have been touted as having sub-millisecond response times. What isn’t talked about as often is the fact that this only applies to G2G transitions. Black-to-gray (or black-to-anything) can take significantly longer (multiple refresh rate cycles), even in modern high-end panels seen on expensive smartphones and laptops, resulting in visible smearing in fast moving images on black backgrounds. The HTC Vive virtual reality headset will never show true black for this reason. Instead, “black” in the HTC Vive is just a very dark gray, similar to what you’d see on a “black” LCD. This brings me to my next point.

The biggest selling point of OLEDs is the fact that they are emissive displays, meaning each pixel produces its own light and each pixel can be individually turned off, allowing for black regions of the screen to be completely black (“infinite contrast”). However, in contexts where motion blur ideally needs to be minimal (such as fast paced gaming), true black must be avoided to prevent black smearing. So, the next important question is: how dark can the panel get without completely shutting off the pixels? The answer to this seems to generally be: not any darker than an LCD, as seen in the HTC Vive. (I have not been able to find many examples of this from different panels, so I may be wrong here. My HTC Vive’s black looks similar to a black LCD, and my iPhone 12 on minimum brightness with a darkest-gray image also looks similar to a black LCD.)

So: in contexts where motion blur must be small, the “infinite contrast” of OLED is reduced to roughly the same as LCD. OLED does retain the advantage of sub-millisecond G2G response time, though. So you can’t have your cake and eat it too; you have to decide between the two advantages of OLED — no ghosting, or true blacks.

Can anyone with more knowledge chime in on this topic? Have black smearing and/or minimum brightness been improved in any of the more recent OLED panels? Is it even theoretically possible to fix these issues completely? What physically causes these issues to begin with? Does microLED have these issues? I haven’t been able to find any good discussion about this.

[RealNC]

I don't have an OLED display, but everything I've heard from people who have one (TV though, no idea about OLED computer monitors) say that even though there can still be some ghosting if you look close, it's way less than on any LCD display. But again, this is regarding TVs. So it's about 60Hz content.

Btw, OLED's "infinite contrast ratio" is just a mathematical trick. If the black level is zero, then any amount of brightness divided by zero can be claimed to give an "infinite" ratio. Even if the brightness of the pixels would be barely visible by a human and thus the image borderline invisible, well, it's still "infinite" contrast. Any non-zero number, no matter how small, approaches infinity when dividing it by a number that approaches zero. Just another thing marketing people like to put on the box It's technically correct, which some claim is the best kind of correct, but still it doesn't tell the whole story.

In any event, OLED is not perfect. But the best OLED display will be better than the best LCD one.

[nuninho1980]

For stop the confusion about the response time:
Lower response time doesn't belong less motion blur but yes lower persistence time belongs to reduce motion blur. - Why Do Some OLEDs Have Motion Blur?

[Discorz]

It's still fast enough for true 480 or maybe even 1000Hz.

Yes, its important to note response times and persistance blur are not the same thing.
We need fast response times to exclude bottlenecks for faster (1000Hz) sample-and-hold displays.

[jasswolf]

I'm not seeing it.

The only issue right now with LG's BFI implementation is that it adds 1 frame of input lag.

[Chief Blur Buster]

I'm not seeing it.

The only issue right now with LG's BFI implementation is that it adds 1 frame of input lag.

LC CX OLED BFI is pretty excellent relatively speaking.

Even the "Normal Mode" on OLED has lots of motion blur! You can see the OLED motion blur on the left OLED photographs.

The problem is you still need BFI to fix OLED motion blur.

OLED still has motion blur if you do not use BFI.

The only way to have zero motion blur without BFI is extremely high refresh rates such as 1000Hz.

Blur Busters Learning
- Don't confuse GtG versus MPRT the two pixel response benchmarks.
- Don't confuse BFI versus non-BFI methods of motion blur reduction.

Microsecond pixel response times does not eliminate non-BFI motion blur, because refreshtime is THE motion blur -- pixel visibility time -- aka "persistence" -- aka how long a pixel stays VISIBLE for. Even 0ms GtG has lots of motion blur, if you're trying to skip BFI.

Strobing is a band-aid because we can't do 1000 fps at 1000 Hz yet.
BFI is a band-aid because we can't do 1000 fps at 1000 Hz yet.
Real life is infinite frame rate.
Real life does not flicker.
Etc.

Analog real-life motion isn't correctly simulated by low finite refresh rates, especially with other side effects such as motion blur or stroboscopic effects (The Stroboscopic Effect Of Finite Frame Rates).

[Discorz]

Strobing is a band-aid because we can't do 1000 fps at 1000 Hz yet.
BFI is a band-aid because we can't do 1000 fps at 1000 Hz yet.
Real life is infinite frame rate.
Real life does not flicker.
Etc.

I love this answer! Spot on.

[jasswolf]

Totally understand that, I'm just saying their BFI implementation does a fantastic job as we advance and I'm looking forward to OLED and microLED monitors with this as an excellent stop gap, but they need to fix the 1 frame delay.