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Still confused about HDR screen (Page 2)
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subego
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Nov 19, 2018, 10:28 AM
 
@Oreo

Here’s the idea I’m trying to get across.






Is it clear the 3-bit signal has more range than the 2-bit signal?
( Last edited by subego; Nov 19, 2018 at 12:17 PM. )
     
Spheric Harlot
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Nov 19, 2018, 02:21 PM
 
Originally Posted by subego View Post
@Oreo

Here’s the idea I’m trying to get across.






Is it clear the 3-bit signal has more range than the 2-bit signal?
That is not a permissible conclusion. You've just increased the resolution. The range across maximum-minimum may or may not be the same, greater, or less.
     
subego
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Nov 19, 2018, 03:18 PM
 
The idea I’m going for here is if two things cover the same range, but one does it inadequately, as would be the case if we made a 2-bit representation of the waveform in the bottom image, they’re not covering the same range.

One is covering the range, the other is being pushed past its range.
     
OreoCookie
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Nov 19, 2018, 07:04 PM
 
Originally Posted by subego View Post
@Oreo

Here’s the idea I’m trying to get across.






Is it clear the 3-bit signal has more range than the 2-bit signal?
I understand the idea, but bit depth has nothing to do with range, bit depth determines the resolution. The two have nothing to do with one another.
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Brien
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Nov 19, 2018, 11:35 PM
 
Originally Posted by Spheric Harlot View Post
Good, so now that we’ve finally clarified that the subject here has absolutely nothing to do with HDR photography: is really nobody able to explain what makes a display like in the X and Xs „HDR“?
The TV companies haven’t done a great job of that. Nits should be what matters but there are plenty of TV sets that can play HDR and don’t have the brightness to do it justice.
     
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Nov 20, 2018, 01:16 AM
 
Originally Posted by Brien View Post
The TV companies haven’t done a great job of that. Nits should be what matters but there are plenty of TV sets that can play HDR and don’t have the brightness to do it justice.
TV is just an [expletive] mess. IMHO the biggest problem is actually content. How much HDR content is really out there? How do you know what format it is in? Or even if it is available, whether you can access it where you live with the device of choice or browser of choice. Or perhaps you have to purchase a movie that you legally own on, say BlueRay, a second time just to get it in 4K HDR. Even if you broaden the definition of TV and include computers and tablets, if you connect your screen via an older HDMI standard that lacks content protection, you may be screwed.
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And.reg  (op)
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Nov 20, 2018, 09:49 AM
 
Alright so is the reason that Apple said Xs has an "HDR screen" is that it has the hardware instructions to play HDR content by varying the range in nits per pixel with respect to the instructions set by the HDR content (so, #FFFFFF in this corner at 300 nits, but #FFFFFF in this corner at 600 nits), whereas the original X does not have an "HDR screen" because it can't vary the range in nits like that because it doesn't have the instructions in the A11 hardware for it?
     
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Nov 20, 2018, 10:41 AM
 
Originally Posted by OreoCookie View Post
TV is just an [expletive] mess. IMHO the biggest problem is actually content. How much HDR content is really out there? How do you know what format it is in? Or even if it is available, whether you can access it where you live with the device of choice or browser of choice. Or perhaps you have to purchase a movie that you legally own on, say BlueRay, a second time just to get it in 4K HDR. Even if you broaden the definition of TV and include computers and tablets, if you connect your screen via an older HDMI standard that lacks content protection, you may be screwed.
Thankfully most TVs support the various competing HDR standards, but yes, I did need to upgrade my AVR, HDMI cables, and repurchase a few titles I watch often. One thing that is nice is that MOST Netflix/Amazon original content is 4K HDR.
     
Spheric Harlot
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Nov 20, 2018, 01:32 PM
 
Originally Posted by And.reg View Post
Alright so is the reason that Apple said Xs has an "HDR screen" is that it has the hardware instructions to play HDR content by varying the range in nits per pixel with respect to the instructions set by the HDR content (so, #FFFFFF in this corner at 300 nits, but #FFFFFF in this corner at 600 nits), whereas the original X does not have an "HDR screen" because it can't vary the range in nits like that because it doesn't have the instructions in the A11 hardware for it?
The iPhone X has an HDR display, as per Apple nomenclature:

https://www.apple.com/iphone/compare/
     
subego
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Nov 20, 2018, 06:38 PM
 
Originally Posted by And.reg View Post
Alright so is the reason that Apple said Xs has an "HDR screen" is that it has the hardware instructions to play HDR content by varying the range in nits per pixel with respect to the instructions set by the HDR content (so, #FFFFFF in this corner at 300 nits, but #FFFFFF in this corner at 600 nits), whereas the original X does not have an "HDR screen" because it can't vary the range in nits like that because it doesn't have the instructions in the A11 hardware for it?
My apologies for not answering this earlier.

Independent of the rest of the display architecture, the only difference between an HDR screen and a normal screen is the HDR screen has a noticeably higher contrast.

In that sense the X, XS, and XSM have an HDR screen, because they’re OLED. The screens in the X and XS are identical.

Some take issue with my firm coupling of bit-rate to dynamic range, but both Atmos and HDR10 are higher than 8-bits. Whatever we want to call that quality, it’s gone when put on an 8-bit screen.

All three of these screens are 8-bit. They cannot play HDR video without removing data.

The conclusion I draw from this is it’s marketing bullshit. Also note, when Apple leaves something to the imagination instead of explaining it, it’s generally because the reality ain’t all that.
( Last edited by subego; Nov 20, 2018 at 07:56 PM. )
     
subego
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Nov 20, 2018, 06:47 PM
 
Also, #FFFFFF will always be the maximum intensity of the screen.

Half that intensity can’t also be #FFFFFF, because then there’s no place for 50% grey to go.
     
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Nov 20, 2018, 08:31 PM
 
Originally Posted by subego View Post
My apologies for not answering this earlier.

Independent of the rest of the display architecture, the only difference between an HDR screen and a normal screen is the HDR screen has a noticeably higher contrast.
I think Apple's marketing is more correct than other companies's, although it irks me that also it uses the term HDR in this context. I'm much happier when they make reference to DCI-P3, which is a color space that states quantifies the color gamut of the display.
Originally Posted by subego View Post
Some take issue with my firm coupling of bit-rate to dynamic range, but both Atmos and HDR10 are higher than 8-bits. Whatever we want to call that quality, it’s gone when put on an 8-bit screen.
Why not use the term that has been used since time and memoriam for this, color depth or bit depth? I guess users nowadays don't see it anymore, but if you grew up at a time where you sometimes had to trade color depth for resolution so that one complete image that is to be displayed fits into the video RAM, then you remember the color depth setting and terms like “true color” and “high color”.
Originally Posted by subego View Post
The conclusion I draw from this is it’s marketing bullshit. Also note, when Apple leaves something to the imagination instead of explaining it, it’s generally because the reality ain’t all that.
I think Apple does a much better job at explaining what they mean by HDR, because they make reference to a specific color space. But I wish they'd just not use HDR in this context anyway. Although, since the TV industry has gravitated towards using HDR inaccurately, I understand why the marketing people at Apple would want to use the same term.
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subego
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Nov 20, 2018, 09:16 PM
 
This gets back to one of the definitions of dynamic range being the ratio between brightest white and darkest black.

I consider this the correct definition.

I understand white and black to be defined in color theory as achromatic, so unless I’m missing something, since both terms of the ratio are achromatic, under the above definition dynamic range is achromatic as well.
     
subego
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Nov 20, 2018, 09:18 PM
 
Originally Posted by OreoCookie View Post
Why not use the term that has been used since time and memoriam for this, color depth or bit depth?
I’m working on that.
     
And.reg  (op)
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Nov 20, 2018, 10:08 PM
 
Originally Posted by subego View Post
Also, #FFFFFF will always be the maximum intensity of the screen.

Half that intensity can’t also be #FFFFFF, because then there’s no place for 50% grey to go.
Well #FFFFFF is the color produced when red, green, and blue channels are permitted to display at their highest levels, but the actual intensity of that color depends on the monitor's brightness in nits.

But I see the argument as far as OLED goes. I mean, even Samsung's Q9F is reaching near LG's OLED deep blacks because of local dimming, but doesn't have the OLED burn-in issue (or the obnoxious "see my face" reflection of LG's OLEDs).
     
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Nov 20, 2018, 10:15 PM
 
Originally Posted by subego View Post
This gets back to one of the definitions of dynamic range being the ratio between brightest white and darkest black.
You are missing that dynamic range applies to colors and not just black and white. And even if you consider black and white, note that white is a color defined by its temperature (e. g. 6,500 Kelvin in case of DCI-P3). So a device can have a large dynamic range for one color than another.
Originally Posted by subego View Post
I understand white and black to be defined in color theory as achromatic, so unless I’m missing something [...]
No, white is defined in terms of colors as well, and different whites are classified by their temperature. As I wrote above, the reason is that white of temperature T is defined as the mixture of colors that you get from the radiation emanating from a black body at temperature T. Because the surface of the sun has a temperature of approximately 6,000 Kelvin, this is what humans perceive as white. This is also why the color temperatures of different, commonly used whites hover in that 6,000 Kelvin range (e. g. 5,500 Kelvin or 6,500 Kelvin).
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subego
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Nov 21, 2018, 10:30 AM
 
Let’s just get the black and white part squared before we exponentially complicate things.

Allow me to attempt to restate my last post with greater precision.

One possible definition of dynamic range is the ratio between brightest white and darkest black.

I understand black and white to be defined as different intensities of same color, so unless I’m missing something, since both terms of the ratio are the same color, dynamic range is also that color under the above definition.

To put it another way, the above defines dynamic range as monochromatic.

If we define dynamic range as a polychromatic ratio, like it would have to be if it was in some way a relative measure of gamut width, then the term can’t be applied to a monochromatic medium.

Since it was created to measure a monochromatic medium, black and white film... well, I’m not saying we can’t redefine it to mean something incompatible with what created it, but that’s, like, stone ****ing cold, man.

Not to mention, we’d have to come up with a term for the monochromatic ratio between bright and dark.

Is there not an argument for creating a new term to describe the polychromatic relationship between differently sized gamuts, rather than redefine one term and create another for the orphan? I don’t see the value of going through the extra effort.

Unless the goal is marketing.
( Last edited by subego; Nov 21, 2018 at 10:53 AM. )
     
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Nov 21, 2018, 09:07 PM
 
Originally Posted by subego View Post
Let’s just get the black and white part squared before we exponentially complicate things. [...] One possible definition of dynamic range is the ratio between brightest white and darkest black.
To do that, you need to define what mixture of colors white is. There is no getting around this, and color spaces all include definitions of white as a color. Even when you shoot black and white, you define your white point. When you use a flash, I frequently use “gels” (colored plastic) to change the white point of my flash to suit the ambient light sources.
Originally Posted by subego View Post
I understand black and white to be defined as different intensities of same color, so unless I’m missing something, since both terms of the ratio are the same color, dynamic range is also that color under the above definition.
Dynamic range is defined for a specific color, including white.
Originally Posted by subego View Post
Since it was created to measure a monochromatic medium, black and white film... well, I’m not saying we can’t redefine it to mean something incompatible with what created it, but that’s, like, stone ****ing cold, man.
It is not a redefinition, it has always worked like this. As a photographer, you always had to worry about white balance, which is another way of saying, your definition of what white is. (Just to give you an idea, as a kid I used to have a black and white photo lab that I got for Christmas. I shot black and white film a lot.) Even when you shot black and white, because then you would often use color filters to accentuate differences (and you would implicitly change your definition of white). Ditto for flash photography, if the white point of the external light sources and the flash mismatch, ugly things happen — especially with skin tones. White ≠ white.
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subego
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Nov 21, 2018, 10:43 PM
 
For whatever reason, there’s some form of mismatch between us, and our discussions rarely bear fruit.

I’ll stop wasting your time.
( Last edited by subego; Nov 21, 2018 at 11:46 PM. )
     
Spheric Harlot
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Nov 22, 2018, 03:31 AM
 
Soo...what makes the iPhone X/Xs screen „HDR“, by Apple‘s definition?

Nutshell explanation?
     
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Nov 22, 2018, 04:10 AM
 
Originally Posted by Spheric Harlot View Post
Soo...what makes the iPhone X/Xs screen „HDR“, by Apple‘s definition?
The displays of these phones cover the color space DCI-P3, which offers a larger gamut than sRGB. As you may expect from an Apple product, color accuracy is excellent.
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subego
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Nov 22, 2018, 05:19 AM
 
Originally Posted by Spheric Harlot View Post
Nutshell explanation?
Originally Posted by Apple
Super Retina also features High Dynamic Range (HDR), which supports a broad range of dark and light areas in photos and video. This allows you to see from deep true blacks to pure bright whites while retaining dramatic nuances in between.
...
     
Spheric Harlot
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Nov 22, 2018, 06:21 AM
 
Thanks, guys.

So as Apple uses it, „HDR“ refers to the DCI-P3 space.
     
subego
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Nov 22, 2018, 06:30 AM
 
Originally Posted by Spheric Harlot View Post
Thanks, guys.

So as Apple uses it, „HDR“ refers to the DCI-P3 space.
I understand the range between dark and light areas of a screen to be its contrast ratio.
     
And.reg  (op)
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Nov 22, 2018, 08:27 AM
 
Originally Posted by OreoCookie View Post
The displays of these phones cover the color space DCI-P3, which offers a larger gamut than sRGB. As you may expect from an Apple product, color accuracy is excellent.
That's partially because they use superior displays from LG and Samsung right from the start, so, very little work to calibrate it from there.

But... DCI-P3 has been around since iPhone 7, a year before Apple used the "HDR display" designation on their phones, while iPhone XR has no "HDR display" designation...these being LCD screens which I presume lack local dimming, which are present in many non-OLED HDR TVs.

(Haven't finished my coffee this morning, so pardon me if my post rambles a little)
     
subego
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Nov 23, 2018, 09:05 AM
 
Originally Posted by Spheric Harlot View Post
That is not a permissible conclusion. You've just increased the resolution. The range across maximum-minimum may or may not be the same, greater, or less.
Another way to put this is both versions have neither size or resolution. What those are in the final product is arbitrary. They only have bit-depth.

Similarly, a 1 megapixel image has neither size or resolution. What those are in the final product is arbitrary. It only has a pixel count.

However, I’d say both bit-depth and pixel count show the fundamental relationship between size and resolution.

If I increase the size, I’m fundamentally decreasing the resolution. I increase the resolution, I’m fundamentally decreasing the size.

To put this another way...

A display with a high [X], whatever X is, shows more.

I can’t show more unless I have more.

I don’t have more, unless I have a bigger bucket.
     
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Nov 23, 2018, 09:28 AM
 
Originally Posted by And.reg View Post
That's partially because they use superior displays from LG and Samsung right from the start, so, very little work to calibrate it from there.
In case of the iPhone X at least, and presumably also for the Xs and Xs Max, the display is completely designed by Apple and only manufactured by other companies, just like the iPhone is. Of course, Samsung in particular does a great job making displays for Apple, and there is plenty of skill involved, but Apple has moved to design also this part of their phone.
Originally Posted by And.reg View Post
But... DCI-P3 has been around since iPhone 7, a year before Apple used the "HDR display" designation on their phones, while iPhone XR has no "HDR display" designation...these being LCD screens which I presume lack local dimming, which are present in many non-OLED HDR TVs.
Then either I completely misunderstood something or Apple is imprecise with marketing or HDR is used in multiple ways. So for example, Apple touts as the main features of the iPhone XS and XS Max the super-high contrast ratio and the wide color gamut (i. e. support for the color space DCI-P3). Moreover, it advertises HDR10 capability of the displays, which is a combination of 10 bit color depth and a larger gamut color space.
Originally Posted by Apple
HDR10 and wider stereo sound. With support for Dolby Vision and HDR10 titles from iTunes, Netflix, and Amazon Prime Video, movie night comes to iPhone.2 Wider stereo playback makes it all sound great. And your HDR photos — even those you captured before — will have a 60 percent greater dynamic range.
It could be that by Apple‘s definition, HDR is the combination of high contrast ratio and the wide color space. That is why the iPhone XR is not advertised as having an HDR screen — it lacks the higher contrast ratio that LCDs cannot achieve.
Originally Posted by And.reg View Post
(Haven't finished my coffee this morning, so pardon me if my post rambles a little)
No worries.
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And.reg  (op)
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May 23, 2019, 11:17 AM
 
Alright so, new question... mostly motivated by how awesome the LG OLEDs look when I walk past Best Buy

Suppose that I get a 4K LG OLED. Could I hook up my MacBook to the TV, play a 4K HDR video via YouTube (example) on my MacBook, and have the TV show the video in the full HDR mode?

Also related:

Suppose that I get a 4K LG OLED. Could I hook up my MacBook to a 4K receiver that then plugs into the TV, play a 4K HDR video via YouTube (example) on my MacBook, and have the TV show the video in the full HDR mode?

I'm just thinking that I would like to keep my 5.1 system but that adds more questions like how to have Smart TV features feed back to the receiver to the audio.
     
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May 23, 2019, 11:33 AM
 
If the TV and receiver both support ARC, you can use the single HDMI cable that provides video to the TV to also return audio back to the receiver.
     
And.reg  (op)
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May 23, 2019, 12:28 PM
 
I hadn't even thought of that... maybe I should wait for HDMI 2.1 and eARC.
     
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May 24, 2019, 08:15 AM
 
Originally Posted by And.reg View Post
Alright so, new question... mostly motivated by how awesome the LG OLEDs look when I walk past Best Buy

Suppose that I get a 4K LG OLED. Could I hook up my MacBook to the TV, play a 4K HDR video via YouTube (example) on my MacBook, and have the TV show the video in the full HDR mode?
If your Macbook is new enough, you could connect an HDMI cable to run [email protected] at 8 bits per color. This can be HDR by the definition of "size of the gamut" if you have the right color profile installed on the Mac.

Those LG OLED TVs are awesome, btw.

Also related:

Suppose that I get a 4K LG OLED. Could I hook up my MacBook to a 4K receiver that then plugs into the TV, play a 4K HDR video via YouTube (example) on my MacBook, and have the TV show the video in the full HDR mode?
If the receiver also supports HDMI 2.0, [email protected] with no chroma subsampling, yes.
The new Mac Pro has up to 30 MB of cache inside the processor itself. That's more than the HD in my first Mac. Somehow I'm still running out of space.
     
 
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