Can High Contrast actually be a Negative? - AVS Forum
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post #1 of 89 Old 07-04-2014, 10:53 PM - Thread Starter
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Can High Contrast actually be a Negative?

Watching movies on my calibrated IPS screen with 850:1 contrast ratio and brightness at minimum (about 50 cd/m2 [nit]),
and still, I get blinded by the whites on bright scenes after dark or normal scenes.

I have read that the human eye can only see to about 1000:1 or less with a static (not changing) iris.

I decided to tested this notion with a simple image on my IPS screen and found it true:
Paint two smaller black squares one inside the other, each with a slightly different shade (3 and 4 output of 255 for example), on a white background.
You'll notice that you will not be able to distinguish between the black squares because your eye are "blinded" by the white background.
Now paint the background black, you'll immediately will see the difference in the black squares.




You can save this image on your PC and paint the white square black, see what happens.
You can experiment with different white area sizes to test how your eyes behave.
The bigger the white area the less you can see the black squares (8,8,8 and 10,10,10 of 255,255,255 [RGB]) inside.
Keep in mind that you are watching this test image on your screen with its contrast ratio. On my poor contrast IPS I can't see the black squares.

Now you have a small understanding of what static contrast ratio the human eye can actually see.

I never owned a plasma or oled so I can't share my experience with high contrast ratio when watching movies.
But isn't too high contrast ratio actually removes detail and visibility of shades in small areas? In my experience yes.
If so, imo it'll be a lot worse with HDR or OLED when it comes.

Yes, high contrast makes the image POP a lot (HFR is the extreme edge), but there is a certain ratio between shadow and light that is comfortable for our eyes to watch.
Is it really necessary to blind our eyes from scene to scene with extreme contrast (0 to 4000 [nit] in case of HDR) when casually entertaining ourselves?
Personally I do not want to be straining me eyes when enjoying a movie.

When watching video before sleep, for me its the worst time for extreme iris movement.
I lower the contrast slider to lower the whites even more.

Any of you fellows experience the same?

Last edited by James Freeman; 07-05-2014 at 12:58 AM.
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post #2 of 89 Old 07-04-2014, 11:26 PM
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i think HDR is a totally dumb think.

first of all i don't know how high they aim with it if it's something in the 300 cm² not in the x000 cm² i think this is a useful thing. but alone the power consumption with 4000 or 10000 is not something we can get with low power there are limited in efficiency and light is pure power and we can make that a lot more efficient so power consumption and heat will be ridiculous.


but high contrast doesn't harm it really really useful when most part of the screen are black and this happens a lot. getting a higher contrast without increasing the brightness is not bad at all if you ask me.

my TV has about 320 cm² and i can totally deal with it. ok it has a lot to do with the fact is does something not good when i lower the brightness but this is a different topic
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post #3 of 89 Old 07-05-2014, 12:46 AM - Thread Starter
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Quote:
Originally Posted by mightyhuhn View Post
i think HDR is a totally dumb think.
...getting a higher contrast without increasing the brightness is not bad at all if you ask me.
Yes, the screen whites are not that blinding at 50 cd/m2 when any other light besides the screen is on, they are even too dim,
but when watching in a completely dark room the screen is the only source of light therefor your eyes adjusts to that environment.
In that case 50 cd/m2 can be quite bright compared to the majority shades of grey that are around 0-10 cd/m2 (considering exponential gamma curve).
The contrast ratio of the screen did not change therefor the iris still open to receive an average light of 10 cd/m2 (not scientifically accurate, but just for the example).

For example:
Take an OLED screen with native contrast ratio of 1,000,000:1 and watch a movie that is mastered on a 1,000:1 reference broadcast monitor both set to 100 cd/m2 peak white.
Where do you thing the dark shades on the oled will be? around 0.0001 cd/m2 ... almost invisible, unless of course the blacks on oled displays are controllable, which they should be.

With HDR it's the other way around, the blacks are the same but the whites are scorching bright.
Either end of extreme contrast (OLED or HDR), your eyes have a "human value" of contrast in a static scene of less than 1000:1.

If movies indeed will be mastered for extreme contrast displays in the future, picture this:
HDR: Having to block the sun light (in the movie) to see what's in the shade...
OLED: Having to build a completely sealed black room free of reflecting light, to physically maximize your iris opening to its human limit.

Important note:
The bigger the contrast ratio, the higher the bit depth of the display and content should be (10-bit minimum).
We don't want 2 steps of black form 0.0001 to 0.1 do we.... 8-bit is obsolete above certain low-ish contrast ratio.

IMHO, the engineers at the big companies should work on successfully achieving a static contrast ratio of 3000+:1 (more than enough if you ask me) on a standard LCD technology (IPS preferably).
Maybe this can be done with double layer of active polarization instead of the single polarizer and an liquid crystal layer we have today... brain storming here.

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post #4 of 89 Old 07-05-2014, 01:04 AM
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i always watch in a pitch black room. you should really look at a oled with a black clipping test you are missing the point the human eye can easy see that.
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post #5 of 89 Old 07-05-2014, 01:14 AM - Thread Starter
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The first visible step on the Black Clipping Test chart from the AVS709HD disk should be extremely dark with OLED's native contrast ratio of 1,000,000:1, almost invisible if you set your TV to about 120 cd/m2.

Do you have an OLED display?
If so, do you have a calibration device to measure luminance points of your OLED display?

Important:
Please measure step 2 and 255 (not 0 and 255), to have better understanding whether the gamma curve is tailored or absolute.
It may very well be that step 0 is completely turned off (hence huge contrast ratio),
but step 1 or 2 are way above where they should be on a perfect power curve, which is done to emulate a lesser CR display (2000:1 for example).

If your OLED is connected to a PC this will be a lot easier.
Just paint a black square with step 1 and measure its luminance and write it down, now measure a 255 white square and measure it.
Divide the white by the black to get a closer idea of what visible contrast ratio oled panels actually have.

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post #6 of 89 Old 07-05-2014, 01:36 AM
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i don't have a oled screen. and i done your test too. there was nothing to wonder about and no way to see the difference. is like the black dot effect on the sun even through there are no black dot at all.

but you are missing a huge point. it's true we can't see a lot of dark details when most of the screen is bright but we can see easily everything in the dark parts when nothing is too bright. so super high CR is not really important for bright images but the effect on dark is something else...

so the real question is: at what point can we see the difference between 0 and 4 when most of the screen is 255 with unlimited contrast and when do we do this with a CR of 1000. i wonder if this difference is more than 1 or 2 and most likely it is 0.
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post #7 of 89 Old 07-05-2014, 03:58 AM
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Quote:
Originally Posted by James Freeman View Post
Watching movies on my calibrated IPS screen with 850:1 contrast ratio and brightness at minimum (about 50 cd/m2 [nit]),
and still, I get blinded by the whites on bright scenes after dark or normal scenes.
50cd/m2 should not ever be "blinding" really, unless you are sat in a pitch-dark room with dark-adapted eyes. Even so, it is not very bright.
This is really an issue of brightness, rather than contrast. When we talk about contrast, we are generally talking about how dark the black level gets, not how bright screen is.

Quote:
Originally Posted by James Freeman View Post
I have read that the human eye can only see to about 1000:1 or less with a static (not changing) iris.
Yes, but we have a dynamic range of roughly 1,000,000:1 and the iris is constantly adjusting.
This is why a 1,000:1 display is woefully inadequate, and why a camera which only captures 1,000:1 contrast still requires a display with a much higher contrast. (contrast on the camera is fixed, but exposure changes)

Quote:
Originally Posted by James Freeman View Post
I decided to tested this notion with a simple image on my IPS screen and found it true:
Paint two smaller black squares one inside the other, each with a slightly different shade (3 and 4 output of 255 for example), on a white background.
You'll notice that you will not be able to distinguish between the black squares because your eye are "blinded" by the white background.
Now paint the background black, you'll immediately will see the difference in the black squares.
Yes, and this is why you need a high contrast display. When you are viewing dark images in a dim surround, a low contrast display washes out all the shadow details.
A high contrast display with an appropriate gamma will clearly define every step near black.

Quote:
Originally Posted by James Freeman View Post
I never owned a plasma or oled so I can't share my experience with high contrast ratio when watching movies.
But isn't too high contrast ratio actually removes detail and visibility of shades in small areas? In my experience yes.
You can always lower contrast or adjust gamma (which raises the brightness of shadows without affecting black level) but you cannot fix the black level on a low contrast display.

Quote:
Originally Posted by James Freeman View Post
Yes, high contrast makes the image POP a lot (HFR is the extreme edge), but there is a certain ratio between shadow and light that is comfortable for our eyes to watch.
Is it really necessary to blind our eyes from scene to scene with extreme contrast (0 to 4000 [nit] in case of HDR) when casually entertaining ourselves?
Personally I do not want to be straining me eyes when enjoying a movie.
The world outside is a lot brighter than any of our displays - maybe 10,000 nits in the midday sun. An overcast day is in the 1000-3000 nits range.
If the goal is to produce more realistic images, then brightness needs to be increased.
You aren't going to be watching a small postage-stamped size image in the center of your vision in a totally dark room with an HDR display though - the display should be large enough to fill most of your vision.

Quote:
Originally Posted by James Freeman View Post
When watching video before sleep, for me its the worst time for extreme iris movement.
I lower the contrast slider to lower the whites even more.
You're partly causing this problem for yourself. When you sit in a darkened room with a dim display, your eyes are becoming dark-adapted. Then even this 50cd/m2 is "blinding" to you.
If you keep the ambient light levels and the display brightness higher, your eyes won't be dark-adapted and will handle brightness changes a lot better.

Of course I do agree with you that if you're watching late at night, it can be nice to watch in a dim room with the display brightness turned down low.
I actually have a preset on my TV which sets the color temperature to be warmer (about 5000K instead of 6500K) changes the gamma to make things easier to see, and enables the "Auto Light Limiter" (ABL) which prevents something like a full white screen being displayed at full brightness.
But when it gets like that, maybe it's an indicator that we should be turning the TV off and just going to bed.
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post #8 of 89 Old 07-05-2014, 04:09 AM
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Quote:
Originally Posted by Chronoptimist View Post
Yes, and this is why you need a high contrast display. When you are viewing dark images in a dim surround, a low contrast display washes out all the shadow details.
A high contrast display with an appropriate gamma will clearly define every step near black.
clearness of steps and details are not affect by low CR displays it simply looks bad but no information is lost or not visible if your screen is calibrated. even a 260 CR display should be able to show all gray scale steps possible with 8 bit.
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post #9 of 89 Old 07-05-2014, 04:34 AM
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Originally Posted by mightyhuhn View Post
clearness of steps and details are not affect by low CR displays it simply looks bad but no information is lost or not visible if your screen is calibrated. even a 260 CR display should be able to show all gray scale steps possible with 8 bit.
The higher the contrast, the more defined each step is.
On low contrast displays they have a tendency to blend together in mixed contrast scenes.
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post #10 of 89 Old 07-05-2014, 05:09 AM - Thread Starter
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Quote:
Originally Posted by Chronoptimist
Yes, and this is why you need a high contrast display. When you are viewing dark images in a dim surround, a low contrast display washes out all the shadow details.
A high contrast display with an appropriate gamma will clearly define every step near black.
Quote:
Originally Posted by mightyhuhn View Post
clearness of steps and details are not affect by low CR displays it simply looks bad but no information is lost or not visible if your screen is calibrated. even a 260 CR display should be able to show all gray scale steps possible with 8 bit.
Right, visibility of all 255 steps can be achieved in any contrast ratio.
It's the Gamma Curve and how a 1,000,000:1 CR display handles these 8-bit (especially the lower) steps, is what I'm interested in.

If we only have 8-bit of steps to distribute across our gamma curve, how many steps are we going to have on the lower shades?
If OLED display can display a perfect 2.2 power curve (which it easily can), then the first 5 steps will be almost completely black,
therefor modern blu-rays which mastered in 8-bit which have content in the lower 5 steps will be completely black.

Here is a perfect 2.2 gamma curve: Perfect 2.2 Gamma curve
Here it is zoomed in on the first 20 steps: First 20 steps zoomed
X grid spacing is 1/255 = 0.00392, Y grid spacing is 1/100, so every X square is a step in 8 bit from 0 to 1, and every Y square is 1/100 of full brightness.

I think the current OLED TV's somehow compensate for that by not having pure power curve (which they can easily achieve), but a compensated (read: Elevated) blacks except the 0 step which should be completely off.

Anyway, until somebody can chime in who has an oled TV and a photometer or a calibration device to measure the first and second steps of 8-bit so the we will know what's exactly going on there in terms of bit distribution across the gamma input/output curve.

Quote:
Originally Posted by Chronoptimist
The higher the contrast, the more defined each step is.
Exactly.

This big jump from step 0 to 1 from 255 in OLED TV's is what I'm talking about.
To know what perceived contrast ratio OLED emulates we need to set whites 255 to 100cd/m2 and measure step 1, divide white by black and compare it to other displays.
No way that current OLED displays have pure power curve and you can still see shadow detail of typical 8-bit content which was mastered on an 1000:1 broadcast display.

But if the movie was mastered on a new Sony OLED broadcast monitor with 2.4 pure power curve gamma, watching this movie on a typical 1000:1 display will look like crap
because the shadows will look too bright and the image will be lacking in depth.

000
111
222
333

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post #11 of 89 Old 07-05-2014, 05:14 AM
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don't forget TV material is 16-235 and needs to be expanded adding an error and these oled are most likely 10 bit or 8 bit dither panels
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post #12 of 89 Old 07-05-2014, 06:03 AM
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I have compared my LG OLED with my Panasonic Plasma up close. Trust me, these OLED are not dither panels (plasma is and I can see that).

High contrast does hurt my eyes. When I first got my OLED, the high contrast gives me a lot of eye strains. I have turn the contrast setting on the TV from 100% to 80%. However, that doesn't mean a true black is not necessary. At night with all lights off, I can clearly see my Panasonic plasma's black become dark grey while my OLED remains pitch black.

IMO, a TV needs to have full capability of representing all kinds of video, high contrast or true black. But a movie doesn't have to. Most movies are shoot using low contrast unless the director needs the special artistic representation.
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post #13 of 89 Old 07-05-2014, 06:21 AM
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Quote:
Originally Posted by James Freeman View Post
Right, visibility of all 255 steps can be achieved in any contrast ratio.
It's the Gamma Curve and how a 1,000,000:1 CR display handles these 8-bit (especially the lower) steps, is what I'm interested in.

If we only have 8-bit of steps to distribute across our gamma curve, how many steps are we going to have on the lower shades?
If OLED display can display a perfect 2.2 power curve (which it easily can), then the first 5 steps will be almost completely black,
therefor modern blu-rays which mastered in 8-bit which have content in the lower 5 steps will be completely black.
JND is worse on low contrast displays than high contrast displays.
It is low contrast displays which require compensated gamma curves applied (as specified in BT.1886) not high contrast displays.

And again, the higher contrast the display, the more flexible your options are.
It is trivial for a 1,000,000:1 display to emulate a 1,000:1 display if you want. (though I can't see why you would)


Quote:
Originally Posted by James Freeman View Post
This big jump from step 0 to 1 from 255 in OLED TV's is what I'm talking about.
To know what perceived contrast ratio OLED emulates we need to set whites 255 to 100cd/m2 and measure step 1, divide white by black and compare it to other displays.
No way that current OLED displays have pure power curve and you can still see shadow detail of typical 8-bit content which was mastered on an 1000:1 broadcast display.
Broadcast monitors are typically CRTs or OLEDs. The LCD monitors were not widely adopted.
The CRTs will easily do 10,000:1.

While it would be interesting to have the measurements you suggest, it's not like black level is irrelevant. Black level is extremely important for high quality image reproduction, and anything above zero is not ideal.

Quote:
Originally Posted by James Freeman View Post
But if the movie was mastered on a new Sony OLED broadcast monitor with 2.4 pure power curve gamma, watching this movie on a typical 1000:1 display will look like crap because the shadows will look too bright and the image will be lacking in depth.
The image will be lacking in depth because it only has 1,000:1 contrast.


Quote:
Originally Posted by Foxbat121 View Post
I have compared my LG OLED with my Panasonic Plasma up close. Trust me, these OLED are not dither panels (plasma is and I can see that).
The OLEDs most likely are going to be using some amount of dithering - but it will not be anything like the dithering seen with plasmas.

OLEDs and LCD are capable of true 8/10-bit gradation and use dither to increase accuracy/smoothness of gradation at the expense of adding a small amount of noise.
Good dithering can have an 8-bit panel capable of representing about 11-bits of information.

Plasmas are 1-bit displays (the pixel can only be on or off) and have to use significant amounts of dither to create shades at all, so the image is very noisy.

Quote:
Originally Posted by Foxbat121 View Post
High contrast does hurt my eyes. When I first got my OLED, the high contrast gives me a lot of eye strains. I have turn the contrast setting on the TV from 100% to 80%. However, that doesn't mean a true black is not necessary. At night with all lights off, I can clearly see my Panasonic plasma's black become dark grey while my OLED remains pitch black.
The "contrast" setting on a display actually sets the brightness.
With an LCD you also have a backlight setting in addition to contrast. That is not the case with (most) emissive displays like plasma/oled.

Quote:
Originally Posted by Foxbat121 View Post
IMO, a TV needs to have full capability of representing all kinds of video, high contrast or true black. But a movie doesn't have to. Most movies are shoot using low contrast unless the director needs the special artistic representation.
Exactly. The display should show the content exactly as intended. And it is only possible to do that with a display which has "infinite" contrast.
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post #14 of 89 Old 07-05-2014, 07:03 AM - Thread Starter
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In case you wonder what are the 000 111 222 333 are for, I measure the contrast of my Samsung S4 Phone which is my only OLED possession.
I have put the phone on maximum brightness and measured with i1 Display Pro.

Results:
0 & 255 the Contrast is 102,000:1, very cool, pitch black (maybe even the measuring device limit).
1 & 255 the Contrast is 102,000:1, same (0 & 1 look the same side by side in pitch black room).
2 & 255 the Contrast is 102,000:1, same, hmm...
3 & 255 the Contrast is 4200:1 (visibly quite bright compared to the first 2 pitch black steps).

Yes I know a phone is not a TV but it gives me some perspective on how OLED handles 8-bit input.
On a TV step 1 will probably be visible (not crushed) but I assume in the 10,000:1 (Maximum) contrast ratio range not 100K:1 range, it has to be visible isn't it?
In any case, 8-bit is definitely not enough for OLED to reproduce the first few steps smoothly.

Maybe a rule should be set: OLED contrast measured from the first "non infinity" step....

Foxbat121,
Can you please measure step 1 & 255 on your OLED for us?

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post #15 of 89 Old 07-05-2014, 09:56 AM
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Quote:
Originally Posted by Chronoptimist View Post
Black level is extremely important for high quality image reproduction, and anything above zero is not ideal. ...

The "contrast" setting on a display actually sets the brightness.
For pictures with zero black level, brightness is a more appropriate indication of contrast (in an informal sense) than contrast ratio, because dividing by zero black level does not give a meaningful result. But in comparing two pictures with zero black level, the one with greater peak brightness will obviously have more contrast. Even if black level is not quite perfect, if it is still very low, a small change in black level will have a large numerical impact on contrast ratio, while there might not be any visual difference noticeable.

So on displays with good black levels, I think it makes sense to take what is changed by the contrast control as being contrast.

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post #16 of 89 Old 07-05-2014, 11:03 AM
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I doubt any consumer level meter will even be able to measure OLED IRE level 1/100. At 100 cd/m2 white level and 2.2 power gamma, that would be ~0.004 cd/m2.
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post #17 of 89 Old 07-05-2014, 11:48 AM
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Quote:
Originally Posted by James Freeman View Post
Foxbat121,
Can you please measure step 1 & 255 on your OLED for us?


Sorry, don't have any device to measure it. You can read the professional calibration and measurement here in this post: LG 55EA9800 55" OLED Owner's thread
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post #18 of 89 Old 07-05-2014, 11:53 AM
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I use an OLED, and it is the most comfortable set I have ever used for night time viewing.

The colors and contrast don't wash out when you turn brightness way down, so you can comfortably view a movie with peak brightness set lower than what you can set your ipad or iphone to when using it to read in bed.


If you have a test image I can put it on a USB and see how it looks on the OLED.
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post #19 of 89 Old 07-05-2014, 11:53 AM - Thread Starter
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Quote:
Originally Posted by Wizziwig View Post
I doubt any consumer level meter will even be able to measure OLED IRE level 1/100. At 100 cd/m2 white level and 2.2 power gamma, that would be ~0.004 cd/m2.
Nope.
As you can see, the i1 Display Pro can handle 0.002 no problem (it goes even lower).

Contrast measurement of my Samsung S4 phone:


A nice 100K:1 Contrast Ratio (0 & 255).
Although the next measurable step is only 4200:1 (step 3, 0.052 cd/m2), so for typical video watching the visible contrast is around that.
That's why measuring "visible contrast" on an OLED display should be from step 1 and not 0.

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post #20 of 89 Old 07-07-2014, 09:15 AM
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Quote:
Originally Posted by James Freeman View Post
The first visible step on the Black Clipping Test chart from the AVS709HD disk should be extremely dark with OLED's native contrast ratio of 1,000,000:1, almost invisible if you set your TV to about 120 cd/m2.
Actually, I think this is where things will get confusing for some folks. OLED's do not have a contrast ratio. You can't divide by 0.

Contrast ratio is calculated by peak white divided by peak black.

Or for example:

LG OLED is capable of 372 cd/m2 but it's black measures at 0 cd/m2; you can't do 372/0 to determine contrast ratio. There simply isn't one.

Really with OLED you only have a peak whites to go off of. Maybe they should track gradients and see which TVs are smoother. Might be an interesting thing to see for OLED. I read the LG's do band a bit, so I would expect the Samsung to come out of black smoother.

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post #21 of 89 Old 07-07-2014, 09:32 AM
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Quote:
Originally Posted by Wizziwig View Post
I doubt any consumer level meter will even be able to measure OLED IRE level 1/100. At 100 cd/m2 white level and 2.2 power gamma, that would be ~0.004 cd/m2.
Right, I don't believe so either. Not with any accuracy anyway. The i1D3 is suppose to read down to 0.003 cd/m2 but at what accuracy I wonder. +/- ? cd/m2 or RGB levels.

-SiGGy

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post #22 of 89 Old 07-07-2014, 09:51 AM
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Quote:
Originally Posted by SiGGy View Post
Actually, I think this is where things will get confusing for some folks. OLED's do not have a contrast ratio. You can't divide by 0.

Contrast ratio is calculated by peak white divided by peak black.

Or for example:

LG OLED is capable of 372 cd/m2 but it's black measures at 0 cd/m2; you can't do 372/0 to determine contrast ratio. There simply isn't one.

Really with OLED you only have a peak whites to go off of. Maybe they should track gradients and see which TVs are smoother. Might be an interesting thing to see for OLED. I read the LG's do band a bit, so I would expect the Samsung to come out of black smoother.
it's not confusing you are simply avoiding the question. if the CR is unlimited or very very high doesn't matter at for this question.
his question is can the lower gamma curve seen by the human eye or not is it to dark or not? that's the question and what about 1 and 2 ?
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post #23 of 89 Old 07-07-2014, 09:59 AM
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Quote:
Originally Posted by mightyhuhn View Post
it's not confusing you are simply avoiding the question. if the CR is unlimited or very very high doesn't matter at for this question.
his question is can the lower gamma curve seen by the human eye or not is it to dark or not? that's the question and what about 1 and 2 ?
Actually I didn't; perhaps my point wasn't clear.

I think measuring how smooth the TV comes out of black will determine this (this is actually very complicated). The LG OLED is known to have some banding issues, this to me would say it doesn't necessarily step smoothly for all gradients. No way to know if it doesn't come out of black smooth without testing it.

Part of the problem with this question and OLEDs in general is they have an ABL (peak limiting circuit). Which means they also have dynamic gamma. Just as plasma's did; this is why it's kinda ironic to calibrate a plasma to a "flat gamma" when it was never truly flat but perhaps for the APL of the patterns used.

Really someone needs to see how much of an effect the ABL has on OLED. I'd also assume LG's ABL design is different than Samsung's... For example Panasonic Plasma's tended to lower gamma on low APL scenes, making black details come out more. This made the Panasonic's appear to have better near black resolution.

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post #24 of 89 Old 07-07-2014, 11:31 AM - Thread Starter
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The real question is:
How the gamma curve (input) is placed on this "infinite" light contrast (output) with only 8-bit of steps.

With only 255 steps in 8-bit, the difference between complete darkness and first visible step can be HUGE.
The visible contrast of an OLED display can be a "lousy" 4000:1 when measuring 1 & 255 (or the first visible step to white).
We'll not know till someone actually measures this.

One must remember that above a certain static contrast ratio our eye can't differentiate the shades of black at all (test image in the first post),
which brings us to the original question of: Is too much contrast can be a negative?

Quote:
Originally Posted by Chronoptimist
The higher the contrast, the more defined each step is.
On low contrast displays they have a tendency to blend together in mixed contrast scenes.
This is exactly what I am talking about.
That's why on a 1000:1 display 8-bit is perfectly adequate (the steps have less light distance between them),
but 8-bit on an Infinity:1 display is not enough no matter how you twist it, 5 steps is not enough to utilize all the shadow range OLED can provide.

Step 0 & 255 is Infinity:1, but step 1 & 255 is 4000:1 .... Ain't that a waste?
Am I getting through?

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post #25 of 89 Old 07-07-2014, 01:16 PM
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Quote:
Originally Posted by James Freeman View Post
The real question is:
How the gamma curve (input) is placed on this "infinite" light contrast (output) with only 8-bit of steps.

With only 255 steps in 8-bit, the difference between complete darkness and first visible step can be HUGE.
The visible contrast of an OLED display can be a "lousy" 4000:1 when measuring 1 & 255 (or the first visible step to white).
We'll not know till someone actually measures this.

One must remember that above a certain static contrast ratio our eye can't differentiate the shades of black at all (test image in the first post),
which brings us to the original question of: Is too much contrast can be a negative?


This is exactly what I am talking about.
That's why on a 1000:1 display 8-bit is perfectly adequate (the steps have less light distance between them),
but 8-bit on an Infinity:1 display is not enough no matter how you twist it, 5 steps is not enough to utilize all the shadow range OLED can provide.

Step 0 & 255 is Infinity:1, but step 1 & 255 is 4000:1 .... Ain't that a waste?
Am I getting through?
Absolutely. Yes, there is a point where CR doesn't matter. I have argued this point before. And tried to explain 'blacks' aren't everything. Because honestly a panel that displays 0 cd/m2 for black and a panel that displays .006 cd/m2 the only real difference is simply the pure black. And this requires the lights off... totally blacked out room. The CR is basically pointless beyond that.

Just don't overlook the ABL and the dynamic drive/gamma; this basically sets compression on the Y channel using the APL as it's threshold. (not really, but sorta). What I keep hinting at is results may be worse or better than what you are expecting here depending on the APL and the ABL's interaction.

I do wonder if an algorithm can be used to smooth out steps between the 8 bits...

Finding info on the human eye contrast response is tricky. You need to find one that says what it is with exposure to 20-30fL of light. I'm fairly confident it won't be 1,000,000:1 after exposure. I too have read it's about 1000:1 in normal lighting conditions. Whatever that is....

-SiGGy

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post #26 of 89 Old 07-07-2014, 02:47 PM
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Quote:
Originally Posted by James Freeman View Post
Watching movies on my calibrated IPS screen with 850:1 contrast ratio and brightness at minimum (about 50 cd/m2 [nit]),
and still, I get blinded by the whites on bright scenes after dark or normal scenes.

I have read that the human eye can only see to about 1000:1 or less with a static (not changing) iris.
The eye can do >10x what you've read -- at once -- so I recommend looking for better sources.

As for getting blinded by whites on bright scenes, I'd suggest you calibrate your display to a lower peak white.

High contrast is not hurting. It's not removing detail.

There is no difference in HDMI cables. If you can see the picture without visible dropouts or sparklies, the cable is working at 100%. No other cable will display a better version of that picture. You're simply wrong if you think there is a better digital cable than one that is already working.
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post #27 of 89 Old 07-07-2014, 08:51 PM - Thread Starter
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Quote:
Originally Posted by rogo View Post
The eye can do >10x what you've read -- at once -- so I recommend looking for better sources.

High contrast is not hurting. It's not removing detail.
Beyond a certain CR, your eyes will not be able to discerne shadow detail no matter what your source of information.
You can easily test is with some movies and the simple test image in the first post.

I can post some pictures to prove the point even better.
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Are you suggesting that your LCD represents the threshold of sensitivity where human vision can no longer appreciate a benefit? I don't think that's possible with LCD (or plasma), though both have come close (with their own brand of artifacts). As previously described, scenes where there is little in the way of bright content will be the most beneficial when it comes to an infinite contrast ratio. In no way could this be construed as a negative. With such a display, if you choose not to dial down max brightness, you could always use bias or ambient lighting to mitigate the effects of eye strain.
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post #29 of 89 Old 07-07-2014, 10:14 PM
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What's really happening is the LCD sales force knows that even though they won the war that LCD's picture actually does suck!

It reminds me of someone posting back in 2006 that they didn't like the "contrasty look"! That was long before plasma had achieved the blacks it would one day achieve--long before OLED with its great blacks was around.

The reason people harp on blacks is that they really do exist in the universe! The brightest supernovas of all time do not mean that true black does not exist.

But since LCD has won the war--now we're going to be treated to re-education camps around here telling us why LCD's inferior picture is actually good

That's why I predict that you're not going to see any shootouts that feature Kuro blacks or even Panasonic plasma blacks against current LCD pictures because even the deluded masses can see why LCD is inferior!

I have never seen the brightest white on any display in the world that BLINDS me--none of them do! But I have seen many that do not achieve pure black and I've seen many that are blacker than others.

So get ready to be re-educated around here but I'll never buy it--I wouldn't buy a 1974 Mustang II either even if the whole world bought it!

The way you really know that current LCD sucks is you won't see in the future any currently produced LCDs pitted in any shootouts against the Sharp Elites! Even LCD lovers know that current LCD sucks!

Maybe the aim is for Edge lit LCD to lower contrast even more and more! Then of course we'll hear all the excuses why 4K HAS to be compressed!

Too much contrast--too much resolution--then of course we'll get the excuses why we shouldn't mind buying OLED every three years because the color blue doesn't last--sounds like rear projection
TV lamps that you had to purchase over and over and you'd get the lecture about how watching TV only 3 hours a day was reasonable.

The Artwood rule is always this: whenever you hear anything posted around here ask yourself this simple question: would a display manufacturer profit or not by whatever conclusion or statement that is made? Many times that will you give you the true story!

Always unrepentantly yours--the prophet of the LCD only apocalypse,
Artwood

P.S. It's OK to disagree with me as long as you love to hate me for telling one dimension of the truth! Wow--that sounds as bad as the LCD sales force saying it's OK to know that we suck as long as you'll buy our product!
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post #30 of 89 Old 07-08-2014, 12:09 AM - Thread Starter
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Thank you Artwood,
I love myself too, although I'm not that narcissistic.

I still think there is an adequate CR threashold for entertaining video watching, not reality simulation.

Last edited by James Freeman; 07-08-2014 at 02:34 AM.
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