Understanding the 9.7" iPad Pro's Display: How DCI-P3 and True Tone Work | Hacker News Reader

Understanding the 9.7" iPad Pro's Display: How DCI-P3 and True Tone Work

anandtech.com

123 pointstechenthusiast55 comments

I upgraded from an iPad Air 2 to the new 9.7" Pro for Pencil support. I like having great image quality, but the truth is the Air 2 already looks fantastic. I only cared about doodling, I really wasn't expecting much extra out of the screen.

WOW.

Apple hit it out of the park with this one. There are times using my iPad (which I'm doing right now) where the screen starts to remind me of a Kindle reader. Thanks to retina resolution pictures look fantastic and I can't see any pixels on text. The display is so close to the face of the device (since the gaps and thick screens have been eliminated over the years) that it seems like the pictures on the surface of the device. Now with TrueTone the white point on the display seems to match what's actually in the room.

The end result of all this is that, much like a Kindle, the display seems to "disappear". It times you get this interesting little fact were you feel a bit like you're reading a piece of printed plastic. The giveaways that it's a computer screen of been minimized to such a degree that you can almost trick yourself at times.

I don't know where I'd find some images that use more than the standard sRGB to see what they really look like on this iPad, but just from what I've seen with normal content I'm quite impressed. I really hope Apple includes this technology in the iPhone 7.

It seems like the wallpapers on the new 9.7" iPad Pro are Adobe RGB (displayed as P3).

Beyond that, there's probably nothing that the average user can notice yet, at least until iTunes UHD content comes this year or next year.

Apple is bringing P3 support to Safari. There is already media query to check for P3 screen, which is useful to switch between P3 and sRGB images.

https://drafts.csswg.org/mediaqueries-4/#color-gamut

They might also add support for css colors in P3 color space. (css colors are currently always sRGB).

I kept reading through the article, ploughing through the graphs but at no stage did the author write anything that conveyed how good it was in terms I could relate to. Some things need to be written about subjectively rather than objectively.

Thanks for putting in to words what the article didn't do, to explain that it is a truly great display on this tablet.

There are times using my iPad (which I'm doing right now) where the screen starts to remind me of a Kindle reader.

This looks very interesting.

How are the reflections? If there is an overhead lamp, can you recognize your face on the screen and see the lamp reflection clearly?

Disclaimer: I am in the crowd who despises reflective screens but all the advertisements arrange the devices such that there is no visible reflections when in fact you are staring your own face or reflection of the lamp all the time. I find that most of the companies should be slapped with hefty fine for deeply misleading advertisements.

The Air 2 was pretty good, and the Pro is supposed to be even better. I haven't noticed any issues, but to be honest I use my iPad at home in situations where I don't think glare would come up much. I don't notice my face, but honestly I don't remember having that issue with the Air 2 either.

A thorough look at the screen from DisplayMate: http://www.displaymate.com/iPad_Pro9_ShootOut_1.htm

It's _very_ good.

> The iPad Pro 9.7 has a very innovative low Reflectance screen that reflects just 1.7 percent of the ambient light by using a new Anti-Reflection AR coating. It has by far the lowest screen Reflectance of any mobile display, so its image colors and contrast in high ambient light will appear considerably better than on any other mobile display. It’s a major enhancement that reduces the reflected light glare from the screen by a very impressive factor of 3 to 1 compared to most Tablets and Smartphones.

> Our Contrast Rating for High Ambient Light quantitatively measures screen visibility under bright Ambient Light – the higher the better. As a result of its high Brightness and very low Reflectance, the iPad Pro 9.7 has a Contrast Rating for High Ambient Light of 301, by far the highest that we have ever measured. See the Screen Reflections and Brightness and Contrast sections for measurements and details.

(emphasis mine)

This is very serious review. Thanks for this link.

It looks like they are admitting that the problem of reflections is a serious one and needs addressing. I think that this is very positive.

But just a number does not make any sense, so I looked up some videos. Here is the first one where he turns the tablet around quite in the beginning - https://www.youtube.com/watch?v=7RGbn2oAri8

It looks like that 1.7 percent of reflectance will still cause serious reflections. This is not good enough.

So the rating Outstanding should in fact read still far from barely satisfactory. :(

I hope that people will wise up and start demanding reflection free devices.

I don't understand - why do you care so much about seeing reflections? Why is that an issue? Why should I demand reflection free devices? I like the shiny surface - it's easy to clean and looks smart.

I limit the discussion to the tablets.

First of, reflections distract. If I see a movement, my instinct is to focus on the movement. I do not want that. I want to focus on what is on the screen.

When laying on the table, a reflective surface shines an overhead light source into my eyes. This forces me to carefully position the tablet when not in use. I do not want that.

Reflective surface will mirror my face, I do not want to be constantly conscious about my presence.

You could try a matte screen protector. Overall reflectance will me much higher than the stock screen, and IMO they tend to look a bit fuzzy, but it at least cuts out the mirror reflections.

Yep, I tried them. The problem is that they introduce either noise around edges or rainbow colored noise on light areas. Or both.

Unfortunately it is not comparable to the good matte ISP screen experience.

It's not a new idea, but a very effective one. There was an article on here a while ago where someone converted a 5K iMac screen into a "real" picture hanging on the wall, complete with wooden frame and white point shifting:

http://www.claybavor.com/?p=407

discussion: https://news.ycombinator.com/item?id=10900439

Also see Craig Hockenberry piece, for more on the implications of all this for developers and designers: http://blog.iconfactory.com/2016/04/looking-at-the-future/

One of his key points: As a developer, you’ll quickly realize that the scope of these changes will make your update to Retina graphics look like a walk in the park.

Craig is also currently working on a book “that helps you understand color in laymen’s terms, use color management with step-by-step instructions for popular apps like Photoshop, and guides you with the work necessary to create great looking web and native apps.”

https://abookapart.com/

Why DCI-P3 and not Adobe RGB? While they're roughly the same gamut size, with P3 having more crimsons and Adobe more aquas, Adobe actually covers most of the CMYK color space, while P3 does not (it is lacking in the aquas, like sRGB), and Adobe has a larger gamut in the highlights (due to its less saturated, and therefore brighter, red primary).

Not to mention the fact that Adobe RGB has long been established (albeit not terribly widely used) in the graphics/photo industry. As another poster mentioned, even Apple couldn't find any P3 images to use as wallpapers, so settled on Adobe RGB ones instead.

What's their goal? Are they aiming for better compatibility with digital cinema?

It always seems to me, Apple loves dodging the established choice. Firewire, Thunderbolt, I swear the list is long but I can't remember everything right now.

DCI-P3 actually is the relevant film industry standard here. No consumer displays can do Rec.2020 gamut yet, so P3 is a nice halfway step that is comparable to sRGB, unlike Adobe RGB. And it's "future-proof," because both can use the SMPTE ST-2084 EOTF.

Both the P3 and Rec.2020 gamuts are part of the UHD specification.

Firewire and Thunderbolt both introduced important capabilities that no established choice could even come close to. Apple doesn't wait around for the beige box vendors to come to a consensus on technological advances.

You're upset about questions of merit. I'm just saying it hardly surprises me.

Parent answered with just the facts. You deduce they're upset from nothing at all.

>I'm just saying it hardly surprises me.

Which doesn't convey any information -- except your non-surprised status. It doesn't surprise you because it's something that had to be done, it doesn't surprise you because Apple tends to innovate in those areas, it doesn't surprise you because Apple wants to lock people in, it doesn't surprise you because Apple doesn't play well with other's standards, etc, we don't know which.

When Steve Jobs came back to Apple he did a Q&A session at WWDC. Someone asked him why Apple was moving away from unique (proprietary standards) and Steve said it was pointless to do your own interfaces/standards if the existing ones were good enough and that Apple would only do its own thing when no existing solution would work.

Apple created lightning before USB-C existed. In fact I'd wager USB-C wouldn't exist if Apple hadn't created lightning (it costs money to introduce a new standard after all, and the USB-IF is made up mostly of cheap-ass PC makers who will do anything to save a penny... also why USB-C isn't a solid lug like Lightning).

Apple created Firewire 400 when USB was stuck at 12.

Thunderbolt wasn't Apple's creation, it was Intel's extension of the PCI bus to an external interface. Intel is the one who pushed it as the next great thing and promised to roll it out, then pushed onerous licensing terms and took their sweet time rolling it out to all their chipsets.

Even FaceTime couldn't be open-sourced due to patent trolls winning a lawsuit against Apple over the peer-to-peer protocol it used, resulting in Apple having to redesign it to use a server-based scheme (in other words the reason we don't have cross-OS, cross-device video calling right now is due to patent trolls. Think about that for a minute).

Why hasn't Apple updated the Thunderbolt Display for Retina? Because the DisplayPort spec can't handle the resolution and hasn't been updated for it yet (at least that was the cast last time I looked). I'll also note Apple contributed the mini-DisplayPort spec back which is why anyone can use it now.

Good list.

  In fact I'd wager USB-C wouldn't exist if Apple hadn't created lightning

There are rumors that Apple led the design effort for USB-C. http://daringfireball.net/linked/2015/03/14/apple-usbc

I discovered through relevant contacts that that's not actually true.

You are probably misremembering because Apple frequently dives into new standards early. Mini- and micro-SIM cards come to mind.

(I assume you wouldn't include Windows, or the choices made by Microsoft for Windows as being an "established" choice.)

The only substantial "dodged established choice" I can think of recently is the lightning connector over micro-USB. But that's fair enough, as micro-USB is a hateful connector. Paying a few dollars more per cable is relatively inconsequential.

Yes, DCI-P3 is the film industry standard and is part of the UHD specification.

Right, the article even mentions this:

> DCI-P3 will be the gamut to have when UltraHD content rolls around, and Apple choosing it instead of Adobe RGB was a well planned move.

No, broadcast and Blu-ray 4k specs specify the BT.2020 color space. Of course, you could argue that neither of those are relevant to an iPad.

The UHD spec supports both P3 and Rec.2020. With SMPTE ST-2084, it's thankfully not an issue at all.

Apple doesn't use the exact DCI-P3, they use "Display P3". DCI-P3 has gamma 2.6, while Display P3 has gamma 2.2 (the same as sRGB).

I wonder why they didn't go with the correct gamma? Does sRGB gamma compatibility help here so that they can easily display sRGB images on the screen? Or is gamma 2.6 bad on lcd displays?

OpenGL has native support for sRGB blending, so maybe keeping the same gamma allows them to use the same hardware to accelerate Display P3 blending.

Though I think sRGB's gamma is technically the much more complicated

       {  cs / 12.92,                 cs <= 0.04045
  cl = {
       {  ((cs + 0.055)/1.055)^2.4,   cs >  0.04045

and not exactly 2.2.

It's easy to convert gammas; the worst you get is banding when if you lose resolution and fa r movies this can be done offline, but when two color spaces don't align you'll have to truncate to the intersection where converting making the lager gammuts pointless. So given that nearly all big movies have been filmed and color corrected in P3 for years now, it makes sense to match their gamut, but match common display gammas, so that common sRGB content needs little conversion to be displayed.

Thanks, I didn't know that. Do they actually use sRGB "gamma" (which has a linear region near 0) or do they use a straight 2.2 gamma like Adobe RGB does?

I didn't know that Adobe RGB has a straight 2.2 gamma. :)

I don't know the details about the Apple's gamma curve, but these guys have measured it. Perhaps it gives some answers. (I'm not sure how to read that graph..)

http://www.displaymate.com/Gamma_35.html

There's an interesting comment on the thread from someone calling himself "melgross" who sounds like he knows what he's talking about. ( http://anandtech.com/comments/10265/understanding-the-97-ipa... ) Always hard to be sure but he seems pretty credible.

The TL,DR version of melgross's comment is that Adobe modeled their RGB color space after the old Kodachrome film gamut, which was optimized for colors found in natural outdoor scenes rather than human flesh tones. As such, it's not ideal for general production use, and many professionals have been unsatisfied with it.

Another interesting link from a comment disagreeing with melgross is here: http://www.astramael.com/1

I think there's only shades of truth there. Regardless of where skin tones lie (which generally is within sRGB!), Adobe does cover most of CMYK (whatever failings CMYK may have).

Spoony's comment further down, which links to this: http://www.astramael.com/1 is much more on the spot and provides a very interesting comparison of the three with actual examples.

It's nice to have a wider gamut (I'm using NEC/DELL wide-gamut displays professionally since a decade and I calibrate them regularly), but very few will notice the difference given the incredibly poor contrast in outdoor conditions.

I've recently switched to a newer laptop (lenovo x1 carbon), which is not matte (at least, the version I was given - with the touchscreen). While the resolution and color depth is much better than my previous hp elitebook, the screen is just too glossy. The added contrast is quickly lost due to the extra glare even in normal office conditions.

Nobody seems to care nowdays, but the anti-glare coating makes a huge difference in 90% of the scenarios. The claim of reduced brightness is bullshit unless you're working on a monitor in fixed light conditions.

On a tablet with a pen, which I'd really love to use outside to take notes, the added color depth is going to be useless.

>On a tablet with a pen, which I'd really love to use outside to take notes, the added color depth is going to be useless.

This technology doesn't improve a specific use case for me, so it's useless... Let's ignore the other people, and other use cases.

It sounds like True Tone, especially if you're not concerned with pure color accuracy, is a pretty neat trick that actually works.

It's pretty great. It's less accurate, but it seems better for casual (non-photo editing) content since it appears to behave more like a sheet of paper would look. It helps the screen "disappear".

I've heard reports that photo editing apps (such as Photos, and 3rd party products) disables TrueTone while they're the foreground app to prevent TrueTone from causing you to mess up the color balance.

I'm very happy with it. Like Retina before it, you only really notice it when you don't have it. Very quickly it becomes the 'new normal' and going into settings and switching it off can be a real surprise in many common lighting conditions.

Night Shift is a much bigger effect, and isn't calibrated to your environment, but I like it. I know some people think it's too extreme, and it is noticeable. I'm using it on my 6+ right now and it obvious it's on, but again if I switch it off temporarily the blue-whiteness of the un-shifted display looks horribly sickly. But then the warmer colours work particularly well with the HN colour scheme.

I agree, the effect of turning it off is extremely jarring. It's kind of like using f.lux late at night and then turning it off. The blue light becomes blinding.

"Becomes the new normal" Oh, that's the very best kind of tech!

Who would care about absolute color accuracy rather than perceived color accuracy? Even if you're a graphic designer operating in a standardized lighting condition, True Tone just becomes equivalent to an uncorrected display.

It's like you were reviewing the first pair of shorts you ever had with an elastic band, and you said "Well, it's true the shorts are very comfortable and seems to fit me perfectly. But I'm a Medium, and the shorts don't conform to the definition of that size".

I reckon if they send stuff to print media they must case about the real values.

If you print something displayed on the screen, then that print will more closely match what you see on the screen if True Tone is being used.

That whole section of the review was weird.

The analogy I was going to use was optical correction of fonts. Yes some characters are too big or too small by objective measurement, but if the typographer has done their job well they will look consistent to the human eye, with all its foibles.

Is this a 30-bit display or 24-bit?

The latter (8-bit per channel). Sadly we don't have the memory bandwidth yet in mobile. Hopefully we will for the iPhone 7.

If the frame buffer is 8-bit and in P3 color space, doesn't that mean that there are (way) less than 8 effective bits per channel for sRGB content? That seems like a pretty big compromise if true.

The P3 iMacs are 10-bit, and there the color space looks more like a clear win.

That's correct. There is unfortunately banding since it's only 8-bit. It is definitely an unfortunate short term compromise, though the P3 gamut is still worth the tradeoff.

Also, both the 5K iMacs are 10-bit, while the 4K iMac is actually 8-bit. It's down to the bandwidth of the GPUs.

Reference documentation for anyone interested: https://developer.apple.com/library/mac/releasenotes/MacOSX/....

The 5k iMacs use a 10-bit interface, but the panel is still 8-bit and dithered.

Personally, I am extremely happy with the 5k iMac panel, color-wise (contrast is not great though), dithering seems to work well and it's imperceptible in normal conditions.

Nah, it's both 10-bit and dithered, promise. See the Apple reference documentation I just posted above.

You can tell by comparing a test image across the 4K and 5K iMacs. I first discovered this by doing that comparison at an Apple Store. There's obvious banding on the 4K model that isn't there on the 5K model.

This reminds me of a Dell laptop I had a number of years ago that had a WRGB display that was gorgeous. I still think it looked better (albeit lower res) than current high-end laptop displays.

Why did WRGB never catch on? It seemed so good.

Without diving into the details, RGBW is actually worse than RGB on technical merit. For TVs, the panels are so large that yields are terrible, so they often have to use a white subpixel as a quality compromise.

Reply on news.ycombinator.com