(Now with quick test and solutions) OLEDs crush a lot more near black detail than you think

Michael7877

Active Member
Edit: I added a quick way to optimize your TV in 5 minutes without making and viewing any of the many images I created. It starts in paragraph 3. Plus a configuration trick to try for people who watch their SDR content down below ~150 nits.

The method is not perfect (no tools required) but you'll be between 0 and +5% of the minimum brightness required for optimal shadow detail at your preferred gamma. If the brightness is too high for you, you can lower it further using the trick. If you like it and it's dim enough, great! If it's still too bright, you can use the second trick. If you don't like the first trick you can just use the second (you can't not like the second, it's perfect). If, after the second trick, your TV's still too bright for you, you can lower the brightness the normal way, choosing your preferred balance between picture brightness and shadow detail :)

Ok: (from post 15)
The easy way to find your TV's minimum required brightness for optimal shadow detail is:

Put your TV to Maximum OLED/Peak Brightness and put the OLED light/Brightness slider to 100% of maximum. Get some somewhat dim SDR content playing - not something dark, but a TV show, not a news channel or cable commercials. They are too bright. Adjust the Gamma setting from center down to -1, then -2, and down to -3 (2.2, 2.3, 2.4, 2.5)

Notice how much the overall brightness decreases each time.
Lower brightness with the brightness slider by 10% and repeat.

At some point (it won't take long), the last decrease will not subtract the amount of brightness that it should. Usually people don't use the lowest setting, so lower the brightness by 10% and continue. Once you find the point where the setting you use (probably 2.4) doesn't dim the image as much as it should, note the brightness (Too Dark #1, write it's configuration down) and then change Peak Brightness/OLED light to medium. Set the brightness slider in medium to make you image 10% brighter than "Too Dark #1". If the TV can't get bright enough in medium to even match Too Dark #1, you are finished searching: you've found your minimum brightness. If you can match or surpass Too Dark #1, go to the highest of the two you can reach and go through the gamma settings. Do they all work properly? 10% brighter? They should! Same brightness? It might. If it does, lower the brightness slider 10% and repeat. Is it now too dark to show the proper decrease in brightness? It probably is: you've found your TV's minimum brightness. But if not, continue lowering by 10% until you do and note the brightness (Too Dark #2, write it down). If you can reach Too Dark #2 in low, repeat - go 10% brighter than Too Dark #2, check gamma, lower brightness slider 10%, check gamma. If you see the proper reduction that's probably your minimum, but to be sure, lower brightness by 10% to verify. You're probably done now, but if not, continue the reduction described above through the lower brightnesses until you are. It's a good idea to add 5% to the brightness slider when you're done.
I guarantee you, with a 2.4 gamma you won't be down to 100 nits. But it's not the end of the world! There are steps you can take.

Personally I don't mind higher brightness while watching TV, I watch most things at about 275 nits with gamma of 2.4, sometimes 200 nits gamma 2.3, it depends on the content. If I watch at 100 nits (I go through phases), I put gamma to 2.2 and adjust the colour from 50 to 54. This makes the darker colours pop a bit (like 2.4) without the brightest colours looking too saturated (this is trick#1). Trick 1 works for SDR content down around 100 nits, but not much brighter. Over 160, the brighter colours start to look look too saturated. Your mileage may vary (personal preference and all that).

For some reason, HDR tolerates colour setting increases really well at all brightness and gamma settings, up to 60 and sometimes even past. This is probably because saturated looking colours are nowhere near the video signal's maximum Ie. bright red pants outside in SDR may be 80-100% saturation in, and HDR 25-30%.

Onto trick #2 (for SDR): lowering brightness using the contrast setting. Try not to go below 82, and don't go below 76. Why this works: the contrast setting lowers the white point. Technically this puts the steps near black closer together (all steps, really), but this doesn't matter to video quality because you have a 10 bit panel with 1024 levels showing you 8 bit video with 256. So they're usually stretched apart, so picture quality won't be negatively affected by pushing them a bit closer together with the contrast setting - especially not if your brightness setting (OLED light, Peak Brightness etc) is at a high enough setting that your tv comes out of blacks optimally (it does now if you what I described at the beginning of this post). Then it's better.

I hope this helps some people! Let me know if you have any questions (PM or here)

Optimizing our home theater experience is fun.


Original post below:

I made a bunch of 8 bit 16:9 png files (to zoom into full screen and view in a black room) with different colours/shades near black.
R G B
0 0 1
0 1 0
1 0 0
1 1 0
0 1 1

I made all combinations up to 3 3 3, and many combinations with 4s and 5s

Going from
0 0 0 to
1 0 0
0 1 0
0 0 1

To get the panel to even come out of black with Gamma at 2.4,

Oled "peak luminance" aka "oled light" has to be set to high, with brightness at at least 43/50. Almost full brightness! With gamma 2.2, Medium and 32/50 is required. Even still, all the shades up to 2:2:2 suck!. They're not necessarily the colours they should be, and brighter images are 50/50 displayed darker than the darker images!

And forget colours looking anything like they should with any reliability until 3s are reached, and even then...

2019 A8G. Someone should test their 2020/2021 OLEDs like this. I'm surprised near blacks even appear at all on most people's OLEDs. Have your OLED light to off or low with 2.4 gamma? Nothing but black crush and noise up to the 5s - I can almost guarantee it!

Infinite contrast ratios yeah right! You can't see near blacks without white being 300 nits in SDR with gamma 2.4

Why has literally nobody posted about this? I am appalled, never been so!

Edit: yeah, it's a bit of work to replicate what I did, but a starting point is opening mspaint, creating the custom colours 0 0 0, 1 0 0, 0 1 0, 0 0 1, 1 1 0, 0 1 1, 1 0 1, 1 1 1 and use each one to save a full coloured image 16:9 at 3840x2160, png format. See how bright your TV has to be set to at normal gamma and -2 gamma (2.2 and 2.4) for all of the above combinations to raise black to something visible. Also check that the pictures that total 1 when added are dimmest, 2s are brighter, and 3 is brightest. You can continue and make 2 2 2, 3 3 3, 4 4 4 etc until you get the panel to come out of black... It'd take 30 minutes in an evening.
I hope my TV is malfunctioning, but I bet it's not.
 
Last edited:

gbjbaanb

Active Member
The 4 main manufacturers all choose different processing WRT black detail level. IIRC Panasonic did the best, but the trade off was then something to do with top levels of brightness. Vincent Teoh did some mentions in this in his various reviews.

eg

OLED screens are known for their superb black level, but some of them also tend to exaggerate darkness in some areas, also known as black crush. Here, Panasonic is at its ace, with accurate gradations at the darkest end of the grayscale.

 

mikej

Well-known Member
Vincent frequently mentions near-black handling in his HDTVTest OLED review videos, which show that there are differences between OLED manufacturers in this respect and even between different, successive models from the same manufacturer (eg. this comparison between the LG C9, CX & C1). Presumably the manufacturers have to find the right balance - one that looks the best in real world content and not just on slides.

I watched 'Squid Game' in 4K HDR on my Panasonic OLED last night. Was there any black crush ? I've got no idea but I didn't notice any and it looked fantastic, overall. Even if there was some, I would rather have a little black crush than flashing blocks/artefacts, posterization or blacks that look grey. If it is an issue that is inherent with the technology, then presumably there is a compromise to be made somewhere. As AVForums TV reviews always say, "there is no such thing as the perfect TV".
 

rccarguy2

Distinguished Member
Yeah I noticed difference between kuro and my c9 black crush.
Watch 300 and you can barely see a thing
 

lgans316

Distinguished Member
I would take a bit of crushed blacks over over-exposed shadows caused by grey/milky blacks. It's a topic that's way overblown.
 

gibbletts

Active Member
I made a bunch of 8 bit 16:9 png files (to zoom into full screen and view in a black room) with different colours/shades near black.
R G B
0 0 1
0 1 0
1 0 0
1 1 0
0 1 1

I made all combinations up to 3 3 3, and many combinations with 4s and 5s

Going from
0 0 0 to
1 0 0
0 1 0
0 0 1

To get the panel to even come out of black with Gamma at 2.4,

Oled "peak luminance" aka "oled light" has to be set to high, with brightness at at least 43/50. Almost full brightness! With gamma 2.2, Medium and 32/50 is required. Even still, all the shades up to 2:2:2 suck!. They're not necessarily the colours they should be, and brighter images are 50/50 displayed darker than the darker images!

And forget colours looking anything like they should with any reliability until 3s are reached, and even then...

2019 A8G. Someone should test their 2020/2021 OLEDs like this. I'm surprised near blacks even appear at all on most people's OLEDs. Have your OLED light to off or low with 2.4 gamma? Nothing but black crush and noise up to the 5s - I can almost guarantee it!

Infinite contrast ratios yeah right! You can't see near blacks without white being 300 nits in SDR with gamma 2.4

Why has literally nobody posted about this? I am appalled, never been so!

Edit: yeah, it's a bit of work to replicate what I did, but a starting point is opening mspaint, creating the custom colours 0 0 0, 1 0 0, 0 1 0, 0 0 1, 1 1 0, 0 1 1, 1 0 1, 1 1 1 and use each one to save a full coloured image 16:9 at 3840x2160, png format. See how bright your TV has to be set to at normal gamma and -2 gamma (2.2 and 2.4) for all of the above combinations to raise black to something visible. Also check that the pictures that total 1 when added are dimmest, 2s are brighter, and 3 is brightest. You can continue and make 2 2 2, 3 3 3, 4 4 4 etc until you get the panel to come out of black... It'd take 30 minutes in an evening.
I hope my TV is malfunctioning, but I bet it's not.
Maybe nobody cares
 

Inferno

Distinguished Member
Get your Greyscale Calibrated by a professional and then what you see is what you get, it should get rid of any crush, it's that simple, pay a professional or put up with what you get out of the box inc the crush.
 

JustTheFacts

Active Member
I noticed exaggerated blacks when I first bought my OLED, but after watching it for a while I actually like it. Isn’t HDR exaggerated contrast. The TV manufacturers probably do this intentionally..
 

Michael7877

Active Member
Get your Greyscale Calibrated by a professional and then what you see is what you get, it should get rid of any crush, it's that simple, pay a professional or put up with what you get out of the box inc the crush.

The calibration is nowhere near accurate enough, you must be joking
 

Michael7877

Active Member
I would take a bit of crushed blacks over over-exposed shadows caused by grey/milky blacks. It's a topic that's way overblown.
So would I, and so do I. But I had no idea just how much is actually lost on OLEDs. I guess when they master content they take into account what can be seen on displays, like music mastering and speakers. But you still get a way better experience hearing everything with a highly resolving system. Maybe microled will be intrinsically different than LG OLED and allow for near black detail
 

Michael7877

Active Member
Presumably the manufacturers have to find the right balance - one that looks the best in real world content and not just on slides.
I think it's this. But the fact that I had to turn up to 300 nits and the results still weren't fantastic doesn't bode well for OLED
 

RayP

Well-known Member
The calibration is nowhere near accurate enough, you must be joking
The professional who calibrated mine used a colorimeter costing a great deal of money plus his own skill I don’t possess. My OLED purchased 5 years ago still produces a superb picture.
 

JustTheFacts

Active Member
The professional who calibrated mine used a colorimeter costing a great deal of money plus his own skill I don’t possess. My OLED purchased 5 years ago still produces a superb picture.
As does mine bought last year that was tweaked by me. You just can't beat an OLED
 

Michael7877

Active Member
The professional who calibrated mine used a colorimeter costing a great deal of money plus his own skill I don’t possess. My OLED purchased 5 years ago still produces a superb picture.

There are 10 or 20 level adjustments (depending on your tv) to cover 256 levels. At best you have one adjustment for the first 12 steps. It doesn't matter how good you are or how expensive your tool is, you can't make the first 3 steps brighter without making the next 9 too bright with only one dial for 12 steps. If you don't have 20 point calibration, you have 10 which halves accuracy - the first 3 get fixed and the next 22 are too bright. And that's just 8 bit colour. These are supposedly 10 bit panels, so if talking HDR, multiply the above by 4 - you still only have 10 or 20 points for the 1024 levels. You could be missing the first 10-15 before it comes out of black, and when fixing them, the next 30 or 60 levels (20 and 10 point TVs) are too bright...

I'm not saying OLEDs don't make a good picture, I think they do. And better than anything else except during the day in bright rooms. I love my OLED and wouldn't trade it for anything - not even a new OLED because I have an excellent panel and don't need 4k120 for now. I thought my 3080 would require an upgrade, but it's only really good to 1440p 120, and 4k is a decent ways away (next gen card probably won't do a solid 4k120, it'll be nvidia's 5000 series)

Anyway, my point is, there is plenty of room for improvement with near black handling.

If you are like I was, thinking we have nothing to look forward to with future OLED/microLED TVs except 1500 nits peak brightness and 250 nits full field white, you're wrong. Near black handling improvement is needed with the 1500 peak/250 full field brightness before TVs are perfect. Good enough that I'll be satisfied anyway lol
 
Last edited:

Michael7877

Active Member
An easy way to find your TV's minimum required brightness for optimal shadow detail is:
Put your TV to Maximum OLED/Peak Brightness and put the OLED light/Brightness slider to 100% of maximum. Get some somewhat dim SDR content playing - not something dark, but a TV show, not a news channel or cable commercials. They are too bright. Adjust the Gamma setting from center down to -1, then -2, and down to -3 (2.2, 2.3, 2.4, 2.5)
Notice how much the overall brightness decreases each time.

Lower brightness with the brightness slider by 10% and repeat.

At some point (it won't take long), the last decrease will not subtract the amount of brightness that it should. Usually people don't use the lowest setting, so lower the brightness by 10% and continue. Once you find the point where the setting you use (probably 2.4) doesn't dim the image as much as it should, note the brightness (Too Dark #1, write it's configuration down) and then change Peak Brightness/OLED light to medium. Set the brightness slider in medium to make you image 10% brighter than "Too Dark #1". If the TV can't get bright enough in medium to even match Too Dark #1, you are finished searching: you've found your minimum brightness. If you can match or surpass Too Dark #1, go to the highest of the two you can reach and go through the gamma settings. Do they all work properly? 10% brighter? They should! Same brightness? It might. If it does, lower the brightness slider 10% and repeat. Is it now too dark to show the proper decrease in brightness? It probably is: you've found your TV's minimum brightness. But if not, continue lowering by 10% until you do and note the brightness (Too Dark #2, write it down). If you can reach Too Dark #2 in low, repeat - go 10% brighter than Too Dark #2, check gamma, lower brightness slider 10%, check gamma. If you see the proper reduction that's probably your minimum, but to be sure, lower brightness by 10% to verify. You're probably done now, but if not, continue the reduction described above through the lower brightnesses until you are. It's a good idea to add 5% to the brightness slider when you're done.
I guarantee you, with a 2.4 gamma you won't be down to 100 nits. But it's not the end of the world! There are steps you can take.

Personally I don't mind higher brightness while watching TV, I watch most things at about 275 nits with gamma of 2.4, sometimes 200 nits gamma 2.3, it depends on the content. If I watch at 100 nits (I go through phases), I put gamma to 2.2 and adjust the colour from 50 to 54. This makes the darker colours pop a bit (like 2.4) without the brightest colours looking too saturated (this is trick#1). Trick 1 works for SDR content down around 100 nits, but not much brighter. Over 160, the brighter colours start to look look too saturated. Your mileage may vary (personal preference and all that).

For some reason, HDR tolerates colour setting increases really well at all brightness and gamma settings, up to 60 and sometimes even past. This is probably because saturated looking colours are nowhere near the video signal's maximum Ie. bright red pants outside in SDR may be 80-100% saturation in, and HDR 25-30%.

Onto trick #2 (for SDR): lowering brightness using the contrast setting. Try not to go below 82, and don't go below 76. Why this works: the contrast setting lowers the white point. Technically this puts the steps near black closer together (all steps, really), but this doesn't matter to video quality because you have a 10 bit panel with 1024 levels showing you 8 bit video with 256. So they're usually stretched apart, so picture quality won't be negatively affected by pushing them a bit closer together with the contrast setting - especially not if your brightness setting (OLED light, Peak Brightness etc) is at a high enough setting that your tv comes out of blacks optimally (it does now if you what I described at the beginning of this post). Then it's better.

I hope this helps some people! Let me know if you have any questions (PM or here)
 
Last edited:

RayP

Well-known Member
There are 10 or 20 level adjustments (depending on your tv) to cover 256 levels.
The service menu has more. Many more. That’s the difference between the customer menu and what’s available to the professional.
 

lynx

Senior Moderator
Thread tidy.
 

Inferno

Distinguished Member
The calibration is nowhere near accurate enough, you must be joking
You are joking arn't you, the Professional who did mine did an extremely great job, so why are you talking that rubbish? If you did your own then I'm not surprised really.

And my TV has 22 point calibration.
 

Michael7877

Active Member
You are joking arn't you, the Professional who did mine did an extremely great job, so why are you talking that rubbish? If you did your own then I'm not surprised really.

And my TV has 22 point calibration.

You can check just how good of a job he did with the near blacks by doing the test I suggest. I'd love to hear just how wrong I am, so try it (I actually love being proved wrong).

I don't get why when I'm right, my posts get deleted to spare the feelings of people who are wrong. Objectivity matters
 

JustTheFacts

Active Member
You can check just how good of a job he did with the near blacks by doing the test I suggest. I'd love to hear just how wrong I am, so try it (I actually love being proved wrong).

I don't get why when I'm right, my posts get deleted to spare the feelings of people who are wrong. Objectivity matters
My OLED is spot on . I love every aspect so why change a calibration that I am totally satisfied with. Everybody has different tastes so if you find a benefit in your calibration we are both happy.
 
Last edited:

Inferno

Distinguished Member
You can check just how good of a job he did with the near blacks by doing the test I suggest. I'd love to hear just how wrong I am, so try it (I actually love being proved wrong).

I don't get why when I'm right, my posts get deleted to spare the feelings of people who are wrong. Objectivity matters
I have no interest in massaging your already inflated and incorrect ego, The professional calibrators are probably reading this guff and having a good laugh, Have a good day.
 

fluxedman

Well-known Member
Nice guide thanks, but I think its quite technical and long, might be tricky for many to do.

I think this SDR black crush issue was discussed over on the original massive LG CX thread and there was already a mini guide on getting those black levels tweaked as well as you can yourself its posted here:


I redid his guide to a more easier to understand and do guide, over here:


I felt it worked well with my CX at that time (no longer have an OLED), but it does appear no one was really bothered to tweak the black settings or perhaps my guide was still too confusing.

Most people were happy to leave it on default settings from looks of things and I guess SDR is now fading with everything getting the HD standard if not HDR 4K etc

Still if anyone is up for some Black level tweaking to get those details right under SDR, you now have 3 guides to melt your brain with haha
 

Inferno

Distinguished Member
Nice guide thanks, but I think its quite technical and long, might be tricky for many to do.

I think this SDR black crush issue was discussed over on the original massive LG CX thread and there was already a mini guide on getting those black levels tweaked as well as you can yourself its posted here:


I redid his guide to a more easier to understand and do guide, over here:


I felt it worked well with my CX at that time (no longer have an OLED), but it does appear no one was really bothered to tweak the black settings or perhaps my guide was still too confusing.

Most people were happy to leave it on default settings from looks of things and I guess SDR is now fading with everything getting the HD standard if not HDR 4K etc

Still if anyone is up for some Black level tweaking to get those details right under SDR, you now have 3 guides to melt your brain with haha
I would rather just pay a Professional with all the gear to come and set it correctly, instead of faffing about thinking that I am seeing it correctly, and always wondering if I am seeing correctly, that method of yours is ok if you're unwilling to get it done correctly and know it's correct, once the Greyscale is set accurately then Black Crush disappears, I'll stick to paying.
 

GadgetObsessed

Well-known Member
I would rather just pay a Professional with all the gear to come and set it correctly, instead of faffing about thinking that I am seeing it correctly, and always wondering if I am seeing correctly, that method of yours is ok if you're unwilling to get it done correctly and know it's correct, once the Greyscale is set accurately then Black Crush disappears, I'll stick to paying.
One interesting point in the Philips shootout that I attended was that even after calibration by Steve and Phil from AV Forums, three of the four sets (LG, Philips and Sony) still crushed just above black detail in a very dark/contrasty scene from the Revenant. In this scene there is a relatively bright face in the foreground with someone moving about in the dark background.

The only set that displayed the detail in the background intead of just a plain black background was the Panasonic.

I believe that this was because the Panasonic was the only set which has calibration controls for brightness levels below 5%. On the other sets no matter how good the calibrator or how good their colour meters there is no way to get the just above black level (e.g. 1%, 2%, 3% brightness) to reference levels because there are no controls to adjust these grey scale for these low levels. (There are no extra greyscale controls in the service menu either.)

Another important point to note that was really interesting to me watching the scene, was that I am not sure that the Panasonic image in this scene looked any "better" overall.

Yes it was more accurate (i.e. would be more closely matched to a reference monitor - which is the aim of calibration) and it showed things in the dark background that the other three sets crushed to black. However, by having a dark grey background rather than black the overall scene had less contrast.

I asked Steve about this afterwards and he said that one advantage of crushing near black detail is that it gives such high contrast scenes more "pop".

So overall I was left with the impression that actually crushing very low black levels has advantages and disadvantages so overall fixing the black crush below 5% does not make as much difference as we make out on these forums.
 

The latest video from AVForums

Panasonic LZ2000, LZ1500 & LZ980 Hands-on Launch Event | No QD-OLED for 2022, new 77-inch for LZ2000
Subscribe to our YouTube channel

Latest News

iFi Audio launches new Go bar portable DAC/headphone amp
  • By Ian Collen
  • Published
Sony adds LinkBuds S to its earphone series
  • By Ian Collen
  • Published
T+A announces Solitaire T headphones
  • By Ian Collen
  • Published
Audio-Technica launches ATH-M20xBT wireless headphones
  • By Ian Collen
  • Published
Focal and Naim announce new Special Edition Ash Grey system
  • By Ian Collen
  • Published
Support AVForums with Patreon

Top Bottom