Phonearena on Sony's 4K smartphone

I'm not sure what to think about this article from +PhoneArena

On one hand, they tried to illustrate their point with pictures which is great.

However, showing what you see on screen in photos is very difficult.

Video would be a better medium, since the viewer can build a better visual representation thanks to the multi-frame interpolation operating in our brain.
Also, high resolution photographs is not the best medium to highlight the usefulness of high resolution displays, since depending on the content and capture, fake details coming from sharpening can appear better than higher actual resolution.
Small text or diagrams with a lot of details benefit from high resolution displays more.

With the current state of technology, I will take a Quad HD smartphone over a sometimes(rarely)-4K one any day anyway.
And please, don't kill it with sharpening: halos and artifacts mask and destroy the resolution advantage over 1080p most of the time.

#supercurioBlog #press #critic #display

Kill it before it lays eggs: On the Z5 Premium’s 4K UHD display and why it’s useless
When it comes to display resolution, the law of diminishing returns pretty much renders any discussion moot. In essence, it states that, in most things, at some point further increases in X will results in smaller and smaller gains of Y. Put otherwise, the more you increase pixel count given an identical panel size, the less and less every other pixel will count, as you’ll be reaching a fundamental limit—that of your eyes’ finite resolving power…

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Nexus 6P display lens and color shifting

when viewed even at a slight angle, there is a noticeable color shift to a cooler tonality

+GSMArena​​ review unit, your feedback on +Google+​​ and my blog, all three units I had in hands are the same on this regard.

I don't think +Google​​ and +Huawei​​ made the right choices in terms of polarizer and lens on the Huawei +Nexus​​ 6P.

In the meantime, I've looked at a Lumia 950 in a store today exhibiting no color shifting with viewing angles and good panel uniformity.

Ping +Taylor Wimberly​​

#supercurioBlog #display #Nexus #Nexus6P

Huawei Nexus 6P review: Stepping it up
Last year, a dramatic change came to Google’s Nexus offering. The upper-mid range phone that was the Nexus 5 was replaced by a premium and much more expensive model made by Motorola. Skip time ahead about a year to this fall and we are offered a true premium package with a significantly lower price tag. The Nexus 6P is beautifully designed by Huawei to please both power users and average users alike.

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Nexus 6P sunlight screen legibility

I'm surprised it wasn't highlighted in every review that the Nexus 6P sunlight legibility is poor, for 4 main reasons:

– The automatic brightness at its default settings doesn't adjust to ambient lighting conditions enough.
You have to slam the auto brightness offset slider manually to the maximum so it reaches the maximum brightness allowed.
It is either a defect of the light sensor of my unit or a bug that may need to be filed.

– The amount of internal reflections in the panel is high in today's standards, in no way comparable to an LPTS LCD of the two years old Nexus 5 and its polarized lens generation.

– The maximum brightness allowed by the AMOLED panel driver (measured at 366 cd/m² on my unit) is below average nowadays. Most mid-range smartphones reach higher brightness levels.

– The gamma curve is nearing a 2.4 average at higher brightness levels (it is rarely constant on AMOLEDs)
It makes every color but white itself darker than it should, which only reduces legibility further in challenging environmental conditions.


Bugs, limited hardware characteristics and inadequate calibration together make up one of the poorest sunlight legibility in today's smartphones on the Nexus 6P.

Concretely, it means that if you're used to walk out, exchange message, read articles, you will struggle doing so on the Nexus 6P despite the larger screen.

Some of the shortcomings could be addressed to improve the situation.

#supercurioBlog #display #Nexus #Nexus6P #analysis

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Nexus 6P display measurements, standard mode

With a comparison between maximum brightness and approx 100 cd/m² in order to evaluate the calibration curves scaling.

Average gamma values:
Max (366 cd/m²): 2.37
100 cd/m²: 2.32

Short analysis today due to lack of time:

– The curves, measured with a 256-precision are smooth which indicates the absence of banding in the grayscale.

– The color gamut is extremely large, and color saturation is increased further by the higher gamma: as you can see in the CIE 1932 diagrams, the saturation points are not spaced evenly.
Visual inspection of shows color clipping due to the color processing present to increase color saturation.
Boosting color saturation on such a wide-gamut display is undesirable.

This is the first Nexus AMOLED device boosting color saturation. I wonder if it's intentional or something inherited from the panel supplier default setup.
The color saturation levels are so extreme that I would qualify this color rendition behavior as a bug and encourage to file it as such.

– On slightly lower brightness levels like measured at 100 cd/m², the shadows on this unit become a lot darker, quickly reaching below the minimum the i1 Display Pro sensor used here can read.

– Grayscale RGB levels tracking on this unit is better at 100 cd/m² than at maximum brightness.
This is the reverse of older AMOLED brightness scaling I had experience with, where maximum brightness was the most accurate.
This may vary between units, but it's worth mentioning that lower brightness levels doesn't necessarily equates to reduced color accuracy.
Although this remark is valid for midrange and highlights, the situation tends to degrade in shadows.

– RGB Levels:
Red is lacking.
The colorimeter here can't see things exactly like your eyes: a correction would be required due to the AMOLED spectral characteristics but it still gives an idea with red lacking compared blue and green, compared to a standard target of Natural Daylight D65, which is neither yellow, blue or green, nor warm or cold but average daytime neutral white.
Since our vision is most sensitive to green, it is apparent.
Also since the color temperature formula, giving a warm/cold indication essentially ignored the green component, it is not reflected in the grayscale temperature curves values.

The decision (or oversight) to boost color saturation using color processing by default really leaves me perplex.
Measurements confirms my subjective first impressions 😉

#supercurioBlog #display #color #measurements #analysis


In Album Nexus 6P #1 display measurements, standard

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LG partially explains why it canceled the LG Watch Urbane 2nd Edition

"During aggressive testing over thousands of hours under severe conditions, it was revealed that this component failed to meet LG’s quality standards and could potentially impact our image quality over the life of the device."

Since the watch doesn't have a camera, the only "imaging" component is it's display: a 480×480 P-OLED round panel.
The first generation of the Watch Urbane was already prone to display defects appearing with aging. On the second gen, the higher density might make this occur more often.
It could also be adverse effects of rapid burn-in.
Those who received the few first units now know where to look – sort of.

#supercurioBlog #display #OLED

LG says component affecting image quality behind smartwatch recall
A faulty component in LG’s Watch Urbane 2nd Edition, which had the potential to affect image quality, was behind the smartwatch’s removal from sale

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+Vincent Sergère review of the Nexus 5X for +FrAndroid

Even in case you can't rely on translation from French, take a look at the +GameBench stuff!

He also sent me the measurements, made with my software #SensorMaster of two units, one of which have a lot more yellow white point than the other so that was interesting to have the full data on that.

First unit (more blue): 432 cd/m² maximum white point, 1326:1 contrast ratio
Second unit (more yellow): 495 cd/m² maximum white point, 1527:1 contrast ratio

Interesting discrepancy, because it also means that the yellow one could absolutely be re-calibrated to match the more blue one both in white point, contrast ratio and maximum brightness!

#supercurioBlog #measurements #Nexus #Nexus5X #display

Google Nexus 5X
Le Nexus 5X, issu de la collaboration entre Google et LG, est un terminal qui plaira forcément aux amateurs d’expérience Android pure et notamment aux possesseurs d’un Nexus 5 qui ne veulent pas d’une diagonale d’écran trop élevée. Face à son prédécesseur, le Nexus 5X a beaucoup évolué, notamment sur sa partie photo qui devient enfin utilisable avec des clichés de qualité mais aussi avec son autonomie, même si cette dernière reste encore un peu e…

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Here's the results of the current state of my display calibration algorithm on the early batch Nexus 5 I sent back and its refurbished replacement

Following up on

On both, a 12-bit RGB LUT is loaded in hardware, but as you can see on the curves in these graphs, the panel being only 8-bit, there's some banding going on.
I started working on another driver approach that allows to avoid this 8-bit limitation and permits extremely precise correction.

The target for both is D65 white point (as seen by the sensor for simplification), gamma 2.2 curve with a fine-tuned near-black response to avoid clipping or visual artifacts in shadows and near black, also preserving the color balance as much as possible near black.

The replacement Nexus 5 stays better even when both are calibrated thanks to its higher native brightness, slightly higher contrast ratio, and better consistency in its RGB channels which requires less correction.
Although beside the brightness difference which is appreciable, they look the same.

On both, the grayscale Delta E stays below 1 which is a very good accuracy despite the current 8-bit per channel driver hardware limitation.

Subjectively, it also looks pretty darn good 🙂

Other info:

Maximum brightness – significant difference
original: 381 cd/m², replacement 474 cd/m²

Contrast ratio
original: 862:1, replacement: 891:1

On both, HCFR calculates an average gamma value of 2.18 without black point compensation and 2.21 with.

#supercurioBlog #calibration #display #color #development #measurements


In Album Display Measurements: my calibration algorithm on first batch Nexus vs refurbished replacement

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A few days ago I sent back my Nexus 5, from the first batch shipped to France for a defect behind the glass lens

The replacement unit I received immediately seemed to have a better and brighter display, which is confirmed by the measurements graphs attached.

The replacement is brighter, with warmer white point, its RGB channels curves response are a lot closer across the board.
From comparing two phones, I can't tell if one is just better than the other or if Google improved the factory calibration process.

Neither display's white look like D65 daylight white compared to actual daylight or a reference CRT monitor (regardless of the sensor used).

Other info:

Maximum brightness – significant difference
original: 409 cd/m², replacement 510 cd/m²

Contrast ratio – about the same
original: 926:1, replacement: 952:1

Average gamma – interestingly about the same despite the difference in curves
original: 2.07, replacement: 2.08

Up next: results calibrated 😉

#supercurioBlog #calibration #display #color #measurements


In Album Display Measurements: first batch Nexus 5 vs refurbished replacement

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Nexus 6P AMOLED panel info

"SW: It has a Samsung WQHD AMOLED panel. We have spent a lot of time tuning the white-point and color gamut for these panels – hope you will enjoy the accuracy of the display."

"Yep, confirmed: Nexus 6P has the latest generation panels from Samsung. One of things we deeply care for is the quality and accuracy of the display through which all of us connect with the stuff we care about. We created a very tight spec (white-point temperature, delta-E variance, color-space accuracy, etc) for the 6P WQHD AMOLED panel, so it was important that we use the most cutting edge panel technology available."

That sounds good, and especially after +Dave Burke​​​​​​​​​​ claimed on stage that the display was "very vibrant", this promise of color accuracy will need independent verification 😉

Note that this answer doesn't specify to which color space or white point they decided to conform.
This display will show near exclusively content encoded to sRGB standard (which specifies the white point and RGB primaries, gamut and electronic-optical transfer function – aka EOTF aka gamma curves).
In case the display colorspace they chose is wide gamut, any color accuracy claim is automatically moot given the fact Android doesn't support color any management at the moment.

There are various ways to calibrate a wide gamut AMOLED to conform to sRGB specifications tho: using the panel's factory calibration in conjunction with either:
– the panel's color tuning
– Qualcomm Mobile Display Controller image processing, with basic colorspace conversion or 3D LUT
– the GPU (which taxes some GPU power however)

#supercurioBlog #display #color #calibration #Nexus

Hi, I’m Hiroshi Lockheimer, here at Google with the team that build Nexus 5X & 6P…Ask Us Anything! • /r/IAmA
Yep, confirmed: Nexus 6P has the latest generation panels from Samsung. One of things we deeply care for is the quality and accuracy of the…

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Okay so calibrating the +Sony Smartwatch 3 display colors is gonna be tricky given how the measurements come out

Calculated from data: contrast ratio of 8:1.. yeah, nope that's not right ^^

However you can see quickly why colors on this display look so strange: the blue channel is way off and clips at IRE 82.
It might be a deliberate attempt of the people who profiled the panel to make it appear colder blue than the white point really has.
As you can see on the RGB Levels graph, there is tha much deviation between channels. If you saw the watch display in real life: you probably knew already.

I don't know yet what is it that makes darker values brighter than they should: it might be a content adaptive brightness algorithm tuned for readability.
As seen on the CIE Diagram there might be some more color processing going on as well.

The small size of the display is compared to the size of the X-Rite i1 Display Pro is not making things easy, I'll try tuning my patterns and using the i1 Pro instead.

Well, you gotta start somewhere right?

#supercurioBlog #calibration #color #display


In Album First attempt at measuring Sony Smartwatch 3 display

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