Galaxy S6 OLED Display Technology Shoot-Out
Samsung Galaxy S6
Galaxy S6 Edge
Dr. Raymond M. Soneira
President, DisplayMate Technologies
Corporation
Copyright © 1990-2015 by DisplayMate
Technologies Corporation. All Rights Reserved.
This article, or any part
thereof, may not be copied, reproduced, mirrored, distributed or incorporated
into any other work without
the prior written permission of DisplayMate Technologies Corporation
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Galaxy S6 and S6 Edge
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Introduction
The
key element for a great Smartphone has always been a truly innovative and top
performing display, and the best leading edge Smartphones have always flaunted
their super high tech displays. It’s the display performance that determines
how good and how beautiful everything on the Smartphone looks, including camera
photos, and also how usable and how readable the screen remains in high ambient
lighting. It’s the crown jewel of the Smartphone.
The new Galaxy S6 and Galaxy S6 Edge are Samsung’s latest flagship Smartphones. The Galaxy S series and Galaxy Note series are the
way Samsung shows off its latest and greatest OLED displays and display
technology. They have been alternately releasing one of these models every six
months, so there are two OLED generations per year. Each new generation has
provided significant enhancements and improvements, so they leapfrog each other
in display performance, resulting in a new Best
Performing Display with each new Smartphone
generation. The Galaxy S6 continues this trend, with display performance that
matches or exceeds the Galaxy Note 4, which we measured to be the Best
Performing Smartphone Display in 2014 along with the Best Absolute
Color Accuracy. We’ll examine all of this in detail below…
The new Galaxy S6 and Galaxy S6 Edge are two different versions of the latest Samsung OLED
display technology. Both have 5.1 inch high resolution Quad HD 2560x1440 pixel
displays with 577 pixels per inch, roughly double the number of pixels on the Galaxy S5 or an HDTV.
That’s not only the highest pixel count but also the highest pixels per inch
(ppi) on any Smartphone display. The Galaxy S6 display is made on a traditional perfectly flat and hard
screen – it’s an enhanced version of the display on the Galaxy S5. The display on
the Galaxy S6 Edge is similar, but its OLED display is made using a new
flexible plastic substrate, so that it can bend around on both sides of the
phone to provide two new curved display areas that can be viewed from both the
front or the sides, and also when the phone is placed face down. The curved
Edge screen provides an important User Interface enhancement for Smartphones
that we describe below.
Our detailed series of DisplayMate Lab tests that are listed below show that
there are many significant display performance
improvements in the new Galaxy S6 models, including higher resolution, higher
absolute color accuracy, better calibration, higher peak brightness, better
screen visibility and readability in high ambient light, and higher display
power efficiency, resulting in a number of new performance records for
Smartphone displays. We’ll cover these issues and much more, with in-depth
comprehensive display tests, measurements and analysis that you will find
nowhere else.
Samsung provided DisplayMate Technologies with early pre-release
production units of both the Galaxy S6 and the Galaxy S6 Edge so that we could
perform our well known independent, objective and comprehensive scientific Lab
tests with extensive measurements and analysis, explaining in-depth the display
performance results for consumers, and also as a display technology guide for
reviewers and journalists. This article will focus primarily on testing the
Galaxy S6, but we have also included a section with some test results for the
curved screen Galaxy S6 Edge.
The Display Shoot-Out
To examine the
performance of the Galaxy S6 OLED Displays we
ran our in-depth series of Mobile
Display Technology Shoot-Out Lab tests and measurements in order to
determine how the latest OLED displays have improved. We take display quality
very seriously and provide in-depth objective analysis based on detailed
laboratory tests and measurements and extensive viewing tests with both test
patterns, test images and test photos. To see how far OLED and LCD mobile
displays have progressed in just five years see our 2010 Smartphone
Display Shoot-Out, and for a real history lesson see our original 2006 Smartphone
Display Shoot-Out.
Results Highlights
In this Results section we provide Highlights of the
comprehensive DisplayMate Lab tests and measurements and extensive visual
comparisons using test photos, test images, and test patterns that are covered
in the advanced sections. The main Display Shoot-Out
Comparison Table summarizes the Galaxy S6 Lab measurements in the following
categories: Screen
Reflections, Brightness
and Contrast, Colors
and Intensities, Viewing
Angles, OLED Spectra,
Display
Power. You can also skip these Highlights and go directly to the Galaxy S6 Edge Overview, and the Galaxy
S6 Conclusions.
Systematically Improving OLED
Displays
What is particularly significant and impressive is that
Samsung has been systematically improving OLED display performance twice a year
with each Galaxy generation since 2010. With the Galaxy S6 there are many
significant improvements over the Galaxy S5 that
we tested a year ago, but also over the Galaxy Note 4
that we tested 6 months ago. The most impressive improvements for the Galaxy S6
are in the pixels per inch and resolution, the Absolute Color Accuracy, Peak
Brightness, Contrast and screen readability in High Ambient Light, and in
display Power Efficiency, which we discuss in turn below.
2.5K Quad HD 2560x1440
Display
The Galaxy S5 had a Full HD 1920x1080 pixel display with
2.1 Mega Pixels – state-of-the-art at that time. The Galaxy S6 provides a major
resolution enhancement with a Quad HD 2560x1440 pixel display, the same as the
5.7 inch Galaxy Note 4 but now on a much smaller 5.1 inch screen size. That’s
currently the highest resolution for Smartphones, with 3.7 Mega Pixels, almost
double the number of pixels on an HDTV (and over 4 times the number of pixels
on the iPhone 6). This provides lots of image detail – it can display four
complete HD 1280x720 images at once. The display has Diamond Pixels (see below)
and Sub-Pixel Rendering with 577 pixels per inch (ppi), the highest on any
consumer display, providing significantly higher image sharpness than can be
resolved with normal 20/20 Vision at the typical viewing distances of 10 inches
or more for Smartphones, so the display appears perfectly sharp.
There are some significant advantages in going higher
than the visual acuity for 20/20 Vision at typical viewing distances. For
Smartphones they include a closer match to digital photo resolutions, the
ability to display Full HD 1920x1080 images with an additional 1.6 Mega Pixels
left over for displaying additional content at the same time, plus efficient
and simple rescaling (with small integer ratios) of various HD and Quad screen
resolution formats to improve speed processing efficiency and resulting picture
quality.
In addition, if you really want (or need) to take
advantage of the extra fine display sharpness and resolution above normal 20/20
Vision, you can. If you study and stare at the image on the screen, move it
closer and move it around, you’ll be able to make out considerably more fine
image detail because you are building an integrated visual map of the image in
your brain. So, when you are looking at an image with very finely detailed
graphics and small text, most people with reasonably good vision will be able
to make out and take advantage of the extra sharpness and image detail if they
take the time to do so. See our 2014 Innovative
Displays and Display Technology article for more details.
Multiple Screen Modes and
Color Management
Most Smartphones and Tablets only provide a single fixed
factory display Color Gamut and color calibration, with no way for the user to
alter it based on personal preferences, running applications, or Ambient
Lighting levels. A very important capability provided by the OLED Galaxy S and
Galaxy Note Smartphones and the Galaxy Tab S Tablets is the implementation of
Color Management that provides a number of Screen Modes, each with different
Color Gamuts and levels of user selectable color saturation and display
calibration based on user and application preferences. Color
Management with multiple and varying Color Gamuts are a very useful and
important state-of-the-art capability that all displays will need to provide in
the future. The Galaxy models are the first to have this capability.
The Galaxy S6 has four user selectable Screen Modes:
Adaptive Display, AMOLED Photo, AMOLED Cinema, and the Basic Screen Mode, which
matches the Standard sRGB/Rec.709 Color Gamut that is used for virtually all
current consumer content. See this Figure for the Color Gamuts
of the different tested Screen Modes and the Colors
and Intensities section for measurements and details. We discuss each of
the tested Screen Modes next…
Adaptive Display Mode with a
Wide Color Gamut
The Adaptive Display screen mode provides real-time
adaptive processing to dynamically adjust images and videos – for some
applications it will vary the White Point, Color Gamut, and Color Saturation
based on the image content and the color of the surrounding ambient lighting
measured by the Ambient Light Sensor (which measures color in addition to
brightness). The Adaptive Display mode also delivers significantly higher color
saturation, with 133 percent of the Standard sRGB/Rec.709 Color Gamut, among
the highest that we have ever measured for Smartphones and Tablets. Some people
like the extra saturated vibrant colors, plus it is useful for special
applications, and particularly for viewing the display in medium to high levels
of Ambient Light, because it offsets some of the reflected light glare that
washes out the on-screen image colors.
Note that the Adaptive Display mode is the standard and
default Screen Mode for the Galaxy S6 (and the Galaxy Note 4). Use Display
Settings to switch to the three other available Screen Modes. Below we discuss
the AMOLED Photo and Basic Screen Modes.
AMOLED Photo Mode with an
Adobe RGB Color Gamut
Most high-end digital cameras have an option to use the
Adobe RGB Color Gamut, which is 17 percent larger than the Standard
sRGB/Rec.709 Color Gamut used in consumer cameras. The AMOLED Photo screen mode
on the Galaxy S6 provides a very accurate calibration to the Adobe RGB
standard, which is rarely available in consumers displays, and is very useful
for high-end digital photography and other advanced imaging applications. The
measured Absolute Color Accuracy of the AMOLED Photo screen mode for the Galaxy
S6 is 2.1 JNCD, which is impressively accurate like on the Galaxy Note 4. See
this Figure for an
explanation and visual definition of JNCD and
the Color Accuracy Plots
showing the measured display Color Errors. There are very few consumer displays
that can accurately reproduce Adobe RGB, so this is a significant plus for
serious photography enthusiasts. See the Color
Accuracy section and the Color
Accuracy Plots for measurements and details.
Basic Screen Mode with the Standard sRGB / Rec.709 Color Gamut
The Basic screen mode provides a very accurate Color and
White Point calibration for the Standard sRGB/Rec.709 Color Gamut that is used
to produce virtually all current consumer content for digital cameras, HDTVs,
the internet, and computers, including photos, videos, and movies. The Color
Gamut of the Basic screen mode is very accurate, with a nearly perfect 101
percent of the Standard sRGB/Rec.709 Color Gamut. Even better, the Absolute
Color Accuracy for the Basic screen mode is an impressive 1.6 JNCD, tied with
the Galaxy Note 4 for the most color accurate display
that we have ever measured for a Smartphone or Tablet. It is visually
indistinguishable from perfect, and very likely considerably better than your
living room TV or any display that you own. See this Figure for an explanation
and visual definition of JNCD and the Galaxy S6 Color Accuracy Plots
showing the measured display Color Errors, our Absolute Color
Accuracy Comparison of the leading Smartphones, and also this regarding Bogus Color Accuracy
Measurements.
Use the Basic screen mode for the best color and image
accuracy, which is especially important when viewing photos from family and
friends (because you often know exactly what they actually should look like),
for some TV shows, movies, and sporting events with image content and colors
that you are familiar with, and also for viewing online merchandise, so you
have a very good idea of exactly what colors you are buying and are less likely
to return them. See the Color
Accuracy section and the Color
Accuracy Plots for measurements and details.
Screen Brightness and
Performance in High Ambient Lighting
Mobile displays are often used under relatively bright
ambient lighting, which washes out the image colors and contrast, reducing
picture quality and making it harder to view or read the screen. To be usable
in high ambient lighting a display needs a dual combination of high screen
Brightness and low screen Reflectance – the Galaxy S6 has both. When the
Brightness is set manually, the Galaxy S6 provides up to 432 cd/m2
(Luminance, which is a measure of Brightness sometimes called nits), comparable
or higher than most LCD displays in this size class. Its Screen Reflectance is
4.6 percent, close to the lowest that we have ever measured for a Smartphone.
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 low Reflectance, the
Galaxy S6 has a Contrast Rating for High Ambient Light that ranges from 72 to
94, among the highest that we have ever measured.
More importantly, on
the Galaxy S6 the Maximum Brightness can go much higher when Automatic Brightness is turned On, so that users can’t
permanently park the Manual Brightness slider to very high values, which would
run down the battery quickly. High screen Brightness is
only needed for High Ambient Light, so turning Automatic Brightness On
will not only provide better high ambient light screen visibility but also
longer battery running time.
When Automatic Brightness
is turned On, the Galaxy S6 reaches an impressive 784 cd/m2 (nits)
in High Ambient Light, where high Brightness is really needed – it is the brightest mobile display that we have ever tested.
As a result of its high Brightness and low Reflectance, the Galaxy S6 has a
Contrast Rating for High Ambient Light that ranges from 118 to170, also the highest that we have ever measured for any mobile
display. See the Brightness
and Contrast, the High
Ambient Light and the Screen
Reflections sections for measurements and details.
Super Dimming Mode
The Galaxy S6 also has a Super Dimming Mode that allows
the Maximum Screen Brightness to be set all the way down to just 2 cd/m2
(nits) using the Brightness Slider. This is useful for working comfortably
without eye strain or bothering others in very dark environments, or affecting
the eye’s dark adaptation, such as when using a telescope. The display still
delivers full 24-bit color and the picture quality remains excellent.
Diamond Pixels
A high
resolution screen shot (provided by Samsung) shows an interesting design
and sub-pixel arrangement for the Galaxy S6, which Samsung calls Diamond Pixels.
First of all, the Red, Green, and Blue sub-pixels have very different sizes –
Blue is by far the largest because it has the lowest light emission efficiency,
and Green is by far the smallest because it has the highest efficiency. The
alternating Red and Blue sub-pixel arrangement leads to a 45 degree diagonal
symmetry in the sub-pixel layout. This allows vertical, horizontal, and
particularly diagonal line segments and vectors to be drawn with reduced
aliasing and artifacts, which improves both text and graphics. In order to
maximize the sub-pixel packing and achieve the highest possible pixels per inch
(ppi), that leads to diamond rather than square or stripe shaped Red and Blue
sub-pixels. But not for the Green sub-pixels, which are oval shaped because
they are squeezed between two much larger and different sized Red and Blue
sub-pixels. It’s an interesting form of high-tech display art…
Display Power Efficiency
With each successive generation Samsung has been
systematically improving the power efficiency of their OLED displays. We
measured a 20 percent improvement in display power efficiency between the
Galaxy S5 and the Galaxy S6, which is especially impressive given that the
Galaxy S6 has almost double the number of pixels and therefore much higher
processing overhead. The Galaxy S6 also has an Ultra Power Saving Mode that
lowers the Screen Brightness and also sets the background to Black, both of
which significantly reduce display power and can double the running time on
battery. See the Display
Power section for measurements and details.
Viewing Angle Performance
While Smartphones are
primarily single viewer devices, the variation in display performance with
viewing angle is still very important because single viewers frequently hold
the display at a variety of viewing angles. The angle is often up to 30 degrees,
more if it is resting on a table or desk. While LCDs typically experience a 55
percent or greater decrease in Brightness at a 30 degree Viewing Angle, the
OLED Galaxy S6 display shows a much smaller 27 percent decrease in Brightness
at 30 degrees. This also applies to multiple side-by-side viewers as well, and
is a significant advantage of OLED displays. The Color Shifts with Viewing
Angle are also relatively small. See the Viewing
Angles section for measurements and details.
Viewing Tests
The Galaxy S6 Basic screen mode provides very nice,
pleasing and accurate colors, and picture quality. Although the Image Contrast
is slightly too high (due to a slightly too steep Intensity Scale), the very
challenging set of DisplayMate Test and Calibration Photos that we use to
evaluate picture quality looked Beautiful, even
to my experienced hyper-critical eyes. The Basic screen mode is recommended for
indoor and low ambient light viewing of most standard consumer content for
digital camera, HDTV, internet, and computer content, including photos, videos,
and movies, and also for your online purchases. The Adaptive Display screen
mode has significantly more vibrant and saturated colors. Some people like
that. It is also recommended for viewing in medium to high levels of ambient
lighting because it offsets some of the reflected light glare that washes out
the images.
Galaxy S6 Edge Overview
Along with the Galaxy S6, Samsung is also introducing the Galaxy S6 Edge, which is
almost identical to the Galaxy S6 except that it has a very innovative curved
OLED display that extends and bends around to both the right and left side
edges of the phone. The curved Galaxy S6 Edge provides two additional
separately configurable display areas that can be viewed from both the front or
the sides, or when the phone is placed face down.
The
Galaxy S6 Edge is actually a flexible OLED display manufactured on a flexible
plastic substrate rather than on a traditional perfectly flat and hard screen
like almost all other OLED (and LCD) displays. This allows the display itself
to bend, but it is then placed underneath a hard Gorilla Glass 4 cover for
protection and to maintain its desired shape, which for the Galaxy S6 Edge is
curved along the entire right and left side edges. It is similar to the curved
OLED Galaxy
Note Edge that we tested in 2014, however, the Galaxy S6 Edge is curved on
both the right and left sides.
The curved Galaxy S6
Edge screen is activated only when the main display is off. It then provides a
rotating carrousel of up to 5 screens that you can flip through with your
finger to see the time, weather, color coded notifications like incoming and
missed calls, messages and Emails, plus several active news feeds that
continuously scroll along the Edge (the defaults include Twitter Trends, Yahoo
Finance and Stocks, and Yahoo Sports). The curved Edge screen provides an
important User Interface enhancement for Smartphones. It’s quite functional and
useful, and even fun watching and cycling through the various Edge screens. The
curved Galaxy S6 Edge screen is about 0.25 inches (0.70 cm) wide on each side,
slightly narrower than the Edge screen on the larger Galaxy Note 4. There is a
night clock that will dimly show the time all night long on the Edge screen
(using very little power because only a small section of the OLED screen is
active) so it’s also a nice alarm clock as well.
Galaxy S6 Edge Conclusions
What
is especially important and news worthy is that the performance of the OLED
display on a flexible plastic substrate for the Galaxy S6 Edge (and Galaxy Note
Edge) is now essentially the same as on a traditional flat and hard substrate
for the Galaxy S6, even at 500+ pixels per inch and 2560x1440 resolution. The
most significant point is that curved and flexible displays are definitely the
wave of the future because they offer many important visual and functional
advantages for both mobile displays and TVs as explained in our 2014
Innovative Displays and Display Technology article. Follow DisplayMate on Twitter to learn
about our upcoming curved and flexible display technology coverage.
Galaxy S6 Conclusions: An Impressive
Smartphone Display…
The primary goal of this Display Technology Shoot-Out article
series has always been to publicize and promote display excellence so that
consumers, journalists and even manufacturers are aware of and appreciate the
very best in displays and display technology.
We point out which manufactures and display technologies
are leading and advancing the state-of-the-art for displays by performing
comprehensive and objective scientific Lab tests and measurements together with
in-depth analysis. We point out who is leading, who is behind, who is
improving, and sometimes (unfortunately) who is back pedaling… all based solely
on the extensive objective careful Lab measurements that we also publish, so
that everyone can judge the data for themselves as well… See the Galaxy S6 Display
Shoot-Out Comparison Table for all of the Lab measurements and testing
details, and the Results Highlights section above for
a more general overview with explanations.
OLED Display Evolution
What is particularly significant and impressive is that
Samsung has been systematically improving OLED display performance with every
new Galaxy generation since 2010, when we started tracking OLED
displays. The first notable OLED Smartphone, the Google
Nexus One, came in decidedly last place in our 2010 Smartphone
Display Shoot-Out. In a span of just five years OLED display technology is
now challenging and even exceeding the performance of the best LCDs. The Galaxy
S6 continues this trend of impressive systematic improvements of OLED displays
and technology.
The Best Smartphone Display
The display on the Galaxy S6 has many significant enhancements over the Galaxy S5 that
we tested a year ago. The most impressive are the increases in pixels per inch
(from 432 to 577 ppi), higher pixel resolution (from 1920x1080 with 2.1 Mega
Pixels up to 2560x1440 with 3.7 Mega Pixels), higher Absolute Color Accuracy
(27 percent improvement), higher Peak Brightness (12 percent improvement),
higher screen readability and Contrast in High Ambient Light (10 percent
improvement), and higher display Power Efficiency (20 percent improvement). The
screen size remains the same at 5.1 inches.
The display on the Galaxy S6 matches and even exceeds the performance of
Galaxy Note 4
that we measured in 2014 and rated it as the Best
Performing Smartphone Display that we had ever tested (see the Comparison section below that includes the iPhone 6).
This is a particularly significant enhancement because the Galaxy S6 display is
considerably smaller so the display components needed to be scaled down by 20
percent in area from the larger 5.7 inch Galaxy Note 4.
The Galaxy S6 delivers uniformly consistent all around Top Tier display
performance: it is only the second Smartphone display to ever get all Green
(Very Good to Excellent) Ratings in all test and measurement categories (except
for a single Yellow in the Brightness Variation with Average Picture Level)
since we started the Display Technology Shoot-Out article Series in 2006, an
impressive achievement for a display. The first display to achieve that was the
Galaxy Note 4.
Based on our extensive Lab tests and measurements listed in the Table
below, the Galaxy S6 matches or breaks new records in Smartphone display
performance for: Highest Screen Resolution, Highest Pixels Per Inch, Highest
Absolute Color Accuracy, Highest (Infinite) Contrast Ratio, Highest Peak
Brightness, and Highest Contrast Rating and screen readability in Ambient
Light.
The Galaxy S6 and Galaxy Note 4 are neck-and-neck record holders for
display performance, effectively tied or alternating between first and second
place in almost all categories except screen size for the much larger Galaxy
Note 4, and the much higher pixels per inch for the Galaxy S6. What is
especially impressive is that the overall display specs and performance of the
Galaxy S6 have been maintained or improved after being scaled down by 20
percent in area from Galaxy Note 4. So… The
Galaxy S6 matches the Galaxy Note 4 in overall display excellence and record
performance and joins it as the Best Performing Smartphone Display that we have
ever tested.
See the Comparison section below for LCDs and the iPhone 6, and
the Display
Shoot-Out Comparison Table for all of the Galaxy S6 Lab measurements and
testing details.
Galaxy S6 Edge and Flexible OLED Displays
The Galaxy S6 Edge is
the third generation of flexible OLED displays produced by Samsung. It is
essentially identical to the (regular) Galaxy S6 except for its curved screen. The curved Edge is an important User Interface enhancement
for Smartphones that we described above. It’s quite functional and useful, and
even fun watching and cycling through the various Edge screens. Flexible
OLEDs are at the cutting edge and future of OLED technology. The first
generation flexible OLED was in the Galaxy Round,
with a slightly curved concave screen that significantly reduces screen
reflections and improves image contrast. The second generation was in the Galaxy
Note Edge with a single curved right side screen. The Galaxy
S6 Edge is the third flexible generation – it’s curved on both sides of the
screen but is activated only when the main display is off. All of these OLED
displays are flexible but are maintained permanently curved and rigid under
Gorilla glass – that can and will change in the future, leading to truly
flexible, bendable, and foldable OLED display screens.
Multiple Screen Modes and Color Management
Most
Smartphones only provide a single fixed factory display Color Calibration, with
no way for the user to alter it based on personal preferences, running
applications, or ambient lighting levels. Samsung has implemented Color
Management for their OLED Smartphones and Tablets allowing them to provide
multiple user selectable Screen Modes with different Color Gamuts and Color
Calibrations – other Smartphones only provide a single fixed screen Color Gamut
and factory calibration. Color Management with multiple
and varying Color Gamuts are a very useful state-of-the-art capability that all
displays will need to provide in the future. The Galaxy models including the
Galaxy S6 and Galaxy S6 Edge are the first to have this important capability – see the Next Generation of Mobile Displays section below.
The Most Accurate Colors
The Galaxy S6 Basic Screen Mode provides the most
accurate on-screen image colors of any Smartphone or Tablet display that we
have ever measured (effectively tied with the Galaxy Note 4). See the Galaxy S6 Color Accuracy
Results, our Absolute Color
Accuracy Comparison of the leading Smartphones, and also this regarding Bogus Color Accuracy
Measurements. The measured Absolute Color Error for the Galaxy S6 Basic
Screen Mode is just 1.6 JNCD, tied with the Galaxy Note 4 as the most color accurate display that we have ever measured
for a Smartphone or Tablet, which is visually indistinguishable from perfect,
and is very likely considerably better than your living room TV or any display
that you own. Color Accuracy is especially important when viewing photos
from family and friends (because you often know exactly what they actually
should look like), for some TV shows, movies, and sporting events with image content
and colors that you are familiar with, and also for viewing online merchandise,
so you have a very good idea of exactly what colors you are buying and are less
likely to return them. Select the Basic Screen Mode using Display Settings – it
is not the default screen mode for the Galaxy S6.
Adobe RGB AMOLED Photo Mode
Most high-end digital cameras have an option to use the
Adobe RGB Color Gamut, which is 17 percent larger than the standard
sRGB/Rec.709 Color Gamut used in consumer cameras. The AMOLED Photo screen mode
on the Galaxy S6 provides a very accurate 2.1 JNCD calibration to the Adobe RGB
standard, which is rarely available in consumer displays. It is very useful for
viewing high-end digital photos and other advanced imaging applications. This is
a significant plus for serious photography enthusiasts. Select the AMOLED Photo
screen mode using Display Settings – it is not the default screen mode for the
Galaxy S6.
Adaptive Display Wide Color
Gamut
The Galaxy S6 OLED display’s native Wide Color Gamut in
the Adaptive Display screen mode has significantly more vibrant and saturated
colors, with 133 percent of the Standard sRGB/Rec.709 Color Gamut, among the
highest that we have ever measured for Smartphones and Tablets. Some people
like the extra saturated vibrant colors, plus it is useful for special
applications and is recommended for viewing in medium to high levels of ambient
light because it offsets some of the reflected light glare that washes out the
on-screen image colors. Select the Adaptive Display screen mode using Display
Settings – note that Adaptive Display is the factory default screen mode for
the Galaxy S6.
The Highest Screen Brightness
and Contrast in High Ambient Light
Mobile displays are often used under relatively bright
ambient lighting, which washes out the image colors and contrast, reducing
picture quality and making it harder to view or read the screen. To be usable
in high ambient light a display needs a dual combination of high screen
Brightness and low screen Reflectance – the Galaxy S6 has both. Its screen
Reflectance is 4.6 percent, close to the lowest that we have ever measured for
a Smartphone. When Automatic Brightness is turned On, the Galaxy S6 reaches an
impressive maximum screen Brightness of 784 cd/m2 (nits) in high
Ambient Light, where high screen Brightness is really needed – it is the Brightest mobile display that we have ever tested.
As a result of its high Brightness and low Reflectance, the Galaxy S6 has a Contrast Rating for High Ambient Light that ranges
from 118 to170, also the highest that we have ever measured for any mobile
display.
Higher Display Power Efficiency
With each successive generation Samsung has been
systematically improving the power efficiency of their OLED displays. We
measured an impressive 20 percent improvement in display power efficiency
between the Galaxy S5 and the Galaxy S6.
While LCDs remain more power efficient for images with
mostly full screen white content (like all text screens, for example), OLEDs
are now more power efficient for mixed image content because they are emissive
displays so their power varies with the Average Picture Level (average
Brightness) of the image content. For OLEDs darker content uses less power and
black uses none. For LCDs the display power is fixed and independent of image
content – so an all black screen uses the same amount of power as an all white
screen.
The Galaxy S6 is in fact 23 percent more power efficient
than the iPhone 6 and
iPhone 6 Plus for mixed image content (that includes text together with
photos, videos, and movies, for example) with a typical 50 percent Average
Picture Level, APL. OLEDs have been rapidly improving in their power
efficiency. The balance point has now moved all the way up to 65 percent APL:
the OLED Galaxy S6 is more power efficient for all APLs from zero up through 65
percent, and the iPhone 6 and iPhone 6 Plus LCDs are more efficient for APLs
above 65 percent. See the Display
Power section for measurements and details.
Comparison with LCDs and the iPhone 6 and 6 Plus
LCDs and OLEDs are the two leading mobile display
technologies. The technologies are significantly different and each one has its
own inherent strengths – and both continue to evolve and improve independently.
We recently
evaluated and rated the iPhone 6 and 6 Plus
as the current Best Mobile LCD Displays, while
the Galaxy S6
and Galaxy
Note 4 are the current Best Mobile OLED Displays.
All are impressive and excellent displays with great
state-of-the-art display technology. However, OLED displays have been advancing
at a relentless and fast pace with a constant series of systematic and
strategic improvements, while LCDs have been coasting on their laurels for years.
So although OLEDs started from behind in 2010 they have now pulled ahead on
performance and innovation based on the Lab test and measurement results
reported here. To get back in the game and become more competitive, LCDs will
need to adopt Quantum
Dots and Dynamic
Color Management.
The
Galaxy S6 has more than double
the resolution and more than 4 times the number of pixels as the iPhone 6. It also has
significantly higher peak Brightness, significantly higher Contrast Ratio in
both low and high Ambient Light, significantly higher Absolute Color Accuracy,
significantly better Viewing Angel performance, and has 4 selectable screen
modes instead of a single fixed one on the iPhones.
You can directly compare the data and measurement results
for all four of these displays in detail by using a Tabbed web browser with our
comprehensive Lab measurements and analysis for each of the displays. For each
Tab click on a Link below. The entries are mostly identical with only minor
formatting differences, so it’s easy to make detailed side-by-side comparisons
by simply clicking through the Tabs.
Samsung Galaxy
S6 Lab Measurements Comparison Table
Samsung
Galaxy Note 4 Lab Measurements Comparison Table
Apple iPhone 6 and
6 Plus Lab Measurements Comparison Table
Improvements for the Next
Generations of Mobile Displays
The most important improvements for both OLED and LCD
mobile displays will come from improving their image and picture quality and
screen readability in ambient light, which washes out the screen images,
resulting in reduced image contrast, color saturation, and color accuracy. The
key will be in implementing Dynamic automatic real-time modification of the
display’s Color Gamut and Intensity Scale based the measured current Ambient
Light level in order to have them compensate for the reflected light glare and
image wash out from ambient light as discussed in our 2014
Innovative Displays and Display Technology and SID
Display Technology Shoot-Out articles. The
displays, technologies, and manufacturers that succeed in implementing this new
high ambient light display performance strategy will take the lead in the next
generations of mobile displays… Follow DisplayMate on Twitter to learn
about these developments and our upcoming display technology coverage.
The Next Generation: With display technology advancing rapidly on many different
fronts, things can change again in the next generation of displays – so best
wishes to all of the manufacturers and technologies in innovating and
developing the next generation of even higher-performance displays!
DisplayMate Display Optimization Technology
All
Smartphone and Tablet displays can be significantly improved using
DisplayMate’s proprietary very advanced scientific analysis and mathematical
display modeling and optimization of the display hardware, factory calibration,
and driver parameters. We help manufacturers with expert display procurement,
prototype development, testing displays to meet contract specifications, and
production quality control so that they don’t make mistakes similar to those
that are exposed in our public Display Technology Shoot-Out series for
consumers. This article is a lite version of our advanced scientific analysis –
before the benefits of our DisplayMate
Display Optimization Technology, which can correct or improve all of these
issues. If you are a display or product manufacturer and want to significantly
improve display performance for a competitive advantage then Contact DisplayMate Technologies.
|
|
|
Galaxy S6 and S6 Edge
|
Display Shoot-Out Comparison Table
Below we
examine in-depth the OLED display on the Samsung
Galaxy S6 based on objective Lab
measurement data and criteria.
For
comparisons and additional background information see the Galaxy S5 Display
Technology Shoot-Out,
the Galaxy Note 4
Display Technology Shoot-Out, and the Absolute Color
Accuracy Display Technology Shoot-Out.
For
comparisons with the other leading Smartphone, Tablet and Smart Watch displays
see our Mobile Display
Technology Shoot-Out series.
|
Categories
|
Samsung
Galaxy S6
|
Comments
|
|
Display Technology
|
5.1 inch
OLED with Diamond Pixels
|
Organic Light Emitting Diode
Diamond Pixels
with Diagonal Sub-Pixel Symmetry
|
|
Screen Shape
|
16:9 =
1.78
Aspect
Ratio
|
The Galaxy S6 has the same shape as
widescreen HDTV video content.
|
|
Screen Area
|
11.1
Square Inches
|
A better measure of size than the
diagonal length.
|
|
Display Resolution
|
2560 x
1440 pixels
2.5K Quad
HD
|
Screen Pixel Resolution.
Quad HD can display four 1280x720 HD
images
|
|
Total Number of Pixels
|
3.7
Mega Pixels
|
Total Number of Pixels.
|
|
Pixels Per Inch – PPI
|
577 PPI
with Diamond Pixels
Excellent
|
Sharpness depends on the viewing distance
and PPI.
See this on the
visual acuity for a true Retina Display
|
|
Sub-Pixels Per Inch – SPPI
|
Red
408 SPPI
Green 577
SPPI
Blue
408 SPPI
|
Diamond Pixel displays have only half the
number of
Red and Blue Sub-Pixels as standard RGB
displays.
|
|
Total Number of Sub-Pixels
|
Red 1.8
Million Sub-Pixels
Green 3.7
Million Sub-Pixels
Blue 1.8
Million Sub-Pixels
|
Number of Mega Sub-Pixels for Red,
Green, Blue.
Diamond Pixel displays have only half the
number of
Red and Blue Sub-Pixels as standard RGB
displays.
At this high PPI they aren’t visible even
very close up
due to the use of Sub-Pixel Rendering.
|
|
20/20 Vision Distance
where Pixels or Sub-Pixels
are Not Resolved
|
6.0
inches for White and Green Sub-Pixels with 20/20 Vision
8.4
inches for Red and Blue Sub-Pixels with 20/20 Vision
|
For 20/20 Vision the minimum Viewing Distance
where the screen appears perfectly sharp
to the eye.
At 10 inches from the screen 20/20 Vision
is 344 PPI.
|
|
Display Sharpness
at Typical Viewing Distances
|
Display appears
Perfectly Sharp
Pixels are
not Resolved with 20/20 Vision
at Typical
Viewing Distances of
10 to 16
inches
|
The Typical Viewing Distances for this
screen size
are in the range of 10 to 16 inches.
Also note that eye’s resolution is much
lower for
Red and Blue color content than White
and Green.
|
|
Appears Perfectly Sharp
at Typical Viewing Distances
|
Yes
|
Typical Viewing Distances are 10 to 16
inches
for this screen size.
|
|
Photo Viewer Color Depth
|
Full
24-bit Color
No
Dithering Visible
256
Intensity Levels
|
Many Android Smartphones and Tablets
still have some form of 16-bit color
depth in the Gallery Viewer.
The Samsung Galaxy S6 does not have this
issue.
|
|
Overall Assessments
This section summarizes
the results for all of the extensive Lab Measurements and Viewing Tests
performed on the display
See Screen
Reflections, Brightness
and Contrast, Colors
and Intensities, Viewing
Angles, OLED
Spectra, Display
Power.
The
Galaxy S6 has four user selectable Screen Modes that are calibrated for different applications and user
preferences.
Here
we provide results for the Adaptive Display mode, which is a dynamic Wide
Color Gamut mode, the AMOLED Photo mode,
which
is calibrated for the Adobe RGB Gamut used in high-end digital photography
and other advanced imaging applications, and
the
Basic screen mode, which is calibrated for
the sRGB/Rec.709 Standard that is used for most consumer content including
camera, photo, video,
movie, web, and computers.
|
Categories
|
Adaptive
Display
Wide Color
Gamut
|
AMOLED
Photo mode
Adobe RGB
Gamut
|
Basic mode
sRGB/Rec.709
Gamut
|
Comments
|
|
Viewing Tests
in Subdued Ambient Lighting
|
Very Good
Images
Photos and
Videos
have Vivid
Color
and
Accurate Contrast
Wide Color
Gamut Mode
Intentionally
Vivid Colors
|
Very Good
Images
Adobe RGB
Photos
have
Excellent Color
and
Accurate Contrast
Accurate
Pro Photo Mode
|
Very Good
Images
Photos and
Videos
have
Excellent Color
and
Accurate Contrast
Accurate
Std Mode
|
The Viewing Tests examine the accuracy
of
photographic images by comparing the
displays
to an calibrated studio monitor and
HDTV.
|
|
Variation with Viewing Angle
Colors and Brightness
See Viewing
Angles
|
Small
Color Shifts
with
Viewing Angle
Small
Brightness Shift
with
Viewing Angle
|
Small
Color Shifts
with
Viewing Angle
Small
Brightness Shift
with
Viewing Angle
|
Small
Color Shifts
with
Viewing Angle
Small
Brightness Shift
with
Viewing Angle
|
The Galaxy S6 display has a relatively
small
decrease in Brightness with Viewing
Angle and
relatively small Color Shifts with
Viewing Angle.
See the Viewing
Angles
section for details.
|
|
Overall Display Assessment
Lab Tests and Measurements
|
Excellent OLED Display
Wide Color
Gamut Mode
|
Excellent OLED Display
Accurate
Pro Photo Mode
|
Excellent OLED Display
Accurate
Std Mode
|
The Galaxy S6 OLED Display performed
very well in the Lab Tests and
Measurements.
|
|
|
|
Absolute Color Accuracy
Measured over Entire Gamut
See Figure 2 and Colors
|
Good
Color Accuracy
Colors
More Saturated
Wide Color
Gamut Mode
|
Excellent
Color Accuracy
Color
Errors are Small
Accurate
Pro Photo Mode
|
Excellent
Color Accuracy
Color
Errors are Small
Accurate
Std Mode
|
Absolute
Color Accuracy is measured with a
Spectroradiometer
for 21 Reference Colors
uniformly
distributed within the entire Color Gamut.
See
Figure 2 and Colors
and Intensities for details.
|
|
Image Contrast Accuracy
See Figure 3 and Contrast
|
Very Good
Accuracy
Image
Contrast
Slightly
Too High
|
Very Good
Accuracy
Image
Contrast
Slightly
Too High
|
Very Good
Accuracy
Image
Contrast
Slightly
Too High
|
The
Image Contrast Accuracy is determined by
measuring
the Log Intensity Scale and Gamma.
See
Figure 3 and Brightness
and Contrast for details.
|
|
Performance in Ambient Light
Display Brightness
Screen Reflectance
Contrast Rating
See Brightness
and Contrast
See Screen
Reflections
|
High
Display Brightness
Very Low
Reflectance
High
Contrast Rating
Higher
Brightness with
Auto
Brightness On
|
High
Display Brightness
Very Low
Reflectance
High
Contrast Rating
Higher
Brightness with
Auto
Brightness On
|
High
Display Brightness
Very Low
Reflectance
High
Contrast Rating
Higher
Brightness with
Auto
Brightness On
|
Smartphones
are seldom used in the dark.
Screen
Brightness and Reflectance determine
the
Contrast Rating for High Ambient Light.
See
the Brightness
and Contrast section for details.
See
the Screen
Reflections section for details.
|
|
Overall Display Calibration
Image and Picture Quality
Lab Tests and Viewing Tests
|
Vivid Saturated Colors
Wide Color
Gamut Mode
|
Excellent Calibration
Accurate
Pro Photo Mode
|
Excellent Calibration
Accurate
Std Mode
|
Galaxy S6 display has multiple Screen
Modes
that deliver accurately calibrated colors
and images
and a Wide Color Gamut Mode that is
preferred by
some users and for some applications.
|
|
|
Overall Display Grade
Overall
Assessment
|
Overall Galaxy S6 Display Grade
is Excellent A
The Best Performing Smartphone
Display that we have ever tested.
|
The Galaxy S6 display delivers excellent
image quality, has both Color Accurate and
Wide Color Gamut Vivid Color modes, has
high Screen Brightness and low
Reflectance,
has good Viewing Angles, and is an all
around
top performing Smartphone display.
|
|
Wide Color Gamut Mode
Also Best
for Viewing in
High
Ambient Light
|
Accurate
Pro Photo Mode
For Viewing
High-End
Adobe RGB
Photos
|
Accurate
Std Mode
For Viewing
Most Content
Photo Video
Movie Web
|
|
|
Adaptive
Display
Wide Color
Gamut
|
AMOLED
Photo mode
Adobe RGB
Gamut
|
Basic mode
sRGB/Rec.709
Gamut
|
Comments
|
|
Screen Reflections
All display screens are mirrors good enough to use
for personal grooming – but that is actually a very bad feature…
We measured the light reflected from all directions
and also direct mirror (specular) reflections, which are much more
distracting and cause more eye strain. Many
Smartphones still have greater than 10 percent reflections that make the
screen much harder to read even in moderate ambient
light levels, requiring ever higher brightness settings that waste
precious battery power. Hopefully manufacturers
will reduce the mirror reflections with anti-reflection coatings and
matte or haze surface finishes.
Our Lab Measurements include Average Reflectance
for Ambient Light from All Directions and for Mirror Reflections.
Note that the Screen Reflectance is exactly the same
for all of the Screen Modes.
|
Categories
|
Galaxy
S6
|
Comments
|
|
Average Screen Reflection
Light From All Directions
|
4.6
percent
for
Ambient Light Reflections
Excellent
|
Measured using an Integrating Hemisphere
and
a Spectroradiometer. The best value we
have
ever measured for a Smartphone is 4.4
percent.
|
|
Mirror Reflections
Percentage of Light Reflected
|
5.9 percent
for Mirror Reflections
Very Good
|
These are the most annoying types of
Reflections.
Measured using a Spectroradiometer and a
narrow
collimated pencil beam of light
reflected off the screen.
|
|
Brightness and Contrast
The Contrast Ratio
is the specification that gets the most attention, but it only applies for
low ambient light, which is seldom
the case for mobile displays. Much more important
is the Contrast Rating, which indicates how
easy it is to read the screen
under high ambient lighting and depends on both
the Maximum Brightness and the Screen Reflectance. The larger the better.
The Contrast Rating
determines the on-screen Effective Contrast Ratio
for the display in high ambient light.
|
Categories
|
Adaptive
Display
Wide Color
Gamut
|
AMOLED
Photo mode
Adobe RGB
Gamut
|
Basic mode
sRGB/Rec.709
Gamut
|
Comments
|
|
Measured Average Brightness
50% Average Picture Level
|
Brightness
371 cd/m2
Very Good
|
Brightness
353 cd/m2
Very Good
|
Brightness
354 cd/m2
Very Good
|
This is the Brightness for typical
screen content
that has a 50% Average Picture Level.
|
|
Measured Full Brightness
100% Full Screen White
|
Brightness
348 cd/m2
Very Good
|
Brightness
332 cd/m2
Very Good
|
Brightness
331 cd/m2
Very Good
|
This is the Brightness for a screen that
is entirely
all white with 100% Average Picture
Level.
|
|
Measured Peak Brightness
1% Full Screen White
|
Brightness
432 cd/m2
Excellent
|
Brightness
406 cd/m2
Excellent
|
Brightness
405 cd/m2
Excellent
|
This is the Peak Brightness for a screen
that
has only a tiny 1% Average Picture
Level.
|
|
Measured Auto Brightness
in High Ambient Light
with Automatic Brightness On
|
Brightness
542 – 784
cd/m2
Excellent
|
Brightness
542 – 784
cd/m2
Excellent
|
Brightness
542 – 784
cd/m2
Excellent
|
Some displays including the Galaxy S6
have
higher Brightness in Automatic
Brightness Mode.
|
|
Low Ambient Light
|
|
Lowest Peak Brightness
Super Dimming Mode
Brightness Slider to Minimum
|
2 cd/m2
For Very
Low Light
|
2 cd/m2
For Very
Low Light
|
2 cd/m2
For Very
Low Light
|
This is the Lowest Brightness with the
Slider set to
Minimum. This is useful for working in
very dark
environments. Picture Quality remained
Excellent.
|
|
Black Brightness at 0 lux
at Maximum Brightness Setting
|
0 cd/m2
Outstanding
|
0 cd/m2
Outstanding
|
0 cd/m2
Outstanding
|
Black brightness is important for low
ambient light,
which is seldom the case for mobile
devices.
|
|
Contrast Ratio at 0 lux
Relevant for Low Ambient Light
|
Infinite
Outstanding
|
Infinite
Outstanding
|
Infinite
Outstanding
|
Only relevant for Low Ambient Light,
which is seldom the case for mobile
devices.
|
|
High Ambient Light
|
|
Contrast Rating
for High Ambient Light
The Higher the Better
for Screen Readability
in High Ambient Light
|
76 – 94
Very Good
118 – 170
With Auto
Brightness
Excellent
|
72 – 88
Very Good
118 – 170
With Auto
Brightness
Excellent
|
72 – 88
Very Good
118 – 170
With Auto
Brightness
Excellent
|
Depends on the Screen Reflectance and
Brightness.
Defined as Maximum Brightness / Average Reflectance.
Some displays including the Galaxy S6 have
higher Brightness in Automatic Brightness Mode.
|
|
Screen Readability
in High Ambient Light
|
Very Good A
Excellent
A+
With Auto Brightness
|
Very Good A
Excellent A+
With Auto Brightness
|
Very Good A
Excellent A+
With Auto Brightness
|
Indicates how easy it is to read the
screen
under high ambient lighting. Depends on
both the Screen Reflectance and
Brightness.
See High
Ambient Light Screen Shots
|
|
Colors and Intensities
The Color Gamut, Intensity Scale, and White Point
determine the quality and accuracy of all displayed images and all
the image colors. Bigger is definitely Not Better
because the display needs to match all the standards that were used
when the content was produced. For LCDs a wider
Color Gamut reduces the power efficiency and the Intensity Scale
affects both image brightness and color mixture
accuracy.
The Galaxy S6 Screen Modes are
calibrated for different applications and user preferences.
|
Categories
|
Adaptive
Display
Wide Color
Gamut
|
AMOLED
Photo mode
Adobe RGB
Gamut
|
Basic mode
sRGB/Rec.709
Gamut
|
Comments
|
|
Color of White
Color Temperature in degrees
Measured in the dark at 0 lux
See Figure 1
|
7,346 K
2.1 JNCD
from D65 White
White is
Somewhat Bluish
Intentionally
Bluish Mode
For Some
Applications
the White
Point Will Vary
with the
Ambient Lighting
|
6,450 K
0.2 JNCD
from D65 White
Very Close
to Standard
Accurate
Pro Photo Mode
See Figure 1
|
6,426 K
0.3 JNCD
from D65 White
Very Close
to Standard
Accurate
Std Mode
See Figure 1
|
D65 with 6,500 K is the standard color
of White
for most Consumer Content and is needed
for
accurate color reproduction of all
images.
JNCD is a Just Noticeable Color Difference.
See Figure 1
for the plotted White Points.
See Figure 2 for the
definition of JNCD.
|
|
Color Gamut
Measured in the dark at 0 lux
See Figure 1
|
133 percent
sRGB /
Rec.709
Intentionally
Vivid Colors
Wide Color
Gamut Mode
See Figure 1
|
102
percent
Adobe RGB
Very Close
to Standard
Accurate
Pro Photo Mode
See Figure 1
|
101
percent
sRGB /
Rec.709
Very Close
to Standard
Accurate
Std Mode
See Figure 1
|
sRGB / Rec.709 is the color standard for
most
content and needed for accurate color
reproduction.
Many advanced digital cameras use Adobe
RGB.
A Wide Color Gamut is useful in High
Ambient Light
and for some applications. It can be used
with Color
Management to dynamically change the
Gamut.
|
|
Color Accuracy
|
|
Absolute Color Accuracy
Average Color Error at 0 lux
For 21 Reference Colors
Just Noticeable Color Difference
See Figure 2
|
Average Color Shift
From
sRGB/Rec.709
Δ(u’v’)
= 0.0260
6.5 JNCD
Intentionally
Vivid Colors
Wide Color
Gamut Mode
See Figure 2
|
Average Color Error
From Adobe
RGB
Δ(u’v’)
= 0.0085
2.1 JNCD
Excellent
Accuracy
Accurate
Pro Photo Mode
See Figure 2
|
Average Color Error
From
sRGB/Rec.709
Δ(u’v’)
= 0.0064
1.6 JNCD
Excellent
Accuracy
Accurate
Std Mode
See Figure 2
|
JNCD is a Just Noticeable Color Difference.
See Figure 2 for the
definition of JNCD and for
Accuracy Plots showing
the measured Color Errors.
Average Errors below 3.5 JNCD are Very
Good.
Average Errors 3.5 to 7.0 JNCD are
Good.
Average Errors above 7.0 JNCD are
Poor.
|
|
Absolute Color Accuracy
Largest Color Error at 0 lux
For 21 Reference Colors
Just Noticeable Color Difference
See Figure 2
|
Largest Color Shift
From
sRGB/Rec.709
Δ(u’v’)
= 0.0533
13.3 JNCD
for Cyan-Blue
Intentionally
Vivid Colors
Wide Color
Gamut Mode
See Figure 2
|
Largest Color Error
From Adobe
RGB
Δ(u’v’)
= 0.0225
5.6 JNCD
for Blue
Very Good
Accuracy
Accurate
Pro Photo Mode
See Figure 2
|
Largest Color Error
From
sRGB/Rec.709
Δ(u’v’)
= 0.0167
4.2 JNCD
for Red-Yellow
Very Good
Accuracy
Accurate
Std Mode
See Figure 2
|
JNCD is a Just Noticeable Color Difference.
See Figure 2 for the
definition of JNCD and for
Accuracy Plots showing
the measured Color Errors.
Largest Errors below 7.0 JNCD are
Very Good.
Largest Errors 7.0 to 14.0 JNCD are
Good.
Largest Errors above 14.0 JNCD are
Poor.
This is twice the limit for the Average
Error.
|
|
Intensity Scale
|
|
Dynamic Brightness
Luminance Decrease with
Average Picture Level APL
|
19 percent
Decrease
Good
|
18 percent
Decrease
Good
|
18 percent
Decrease
Good
|
This is the percent Brightness decrease
with APL
Average Picture Level. Ideally should be
0 percent.
|
|
Intensity Scale and
Image Contrast
See Figure 3
|
Smooth and
Straight
Very Good
Slightly
Too Steep
See Figure 3
|
Smooth and
Straight
Very Good
Slightly
Too Steep
See Figure 3
|
Smooth and
Straight
Very Good
Slightly
Too Steep
See Figure 3
|
The Intensity Scale controls image
contrast needed
for accurate Image Contrast and Color
reproduction.
See Figure 3
|
|
Gamma for the Intensity Scale
Larger has more Image Contrast
See Figure 3
|
2.36
Very Good
Gamma
Slightly Too High
|
2.34
Very Good
Gamma
Slightly Too High
|
2.34
Very Good
Gamma
Slightly Too High
|
Gamma is the log slope of the Intensity
Scale.
Gamma of 2.20 is the standard and needed
for
accurate Image Contrast and Color
reproduction.
See Figure 3
|
|
Image Contrast Accuracy
|
Very Good
|
Very Good
|
Very Good
|
See Figure 3
|
|
Viewing Angles
The variation of
Brightness, Contrast, and Color with Viewing Angle is especially important
for Smartphones because
of their larger screen
and multiple viewers. The typical manufacturer 176+ degree specification for
LCD Viewing Angle
is nonsense because that
is where the Contrast Ratio falls to a miniscule 10. For most LCDs there are
substantial
degradations at less
than ±30 degrees, which is not an atypical Viewing Angle for Smartphones and
Tablets.
Note that the Viewing
Angle performance is also very important for a single viewer because the
Viewing Angle can vary
significantly based on
how the Smartphone is held. The Viewing Angle can be very large if resting on
a table or desk.
The
Viewing Angle variations are essentially identical for all of the Screen
Modes.
|
Categories
|
Adaptive
Display
Wide Color
Gamut
|
AMOLED
Photo mode
Adobe RGB
Gamut
|
Basic mode
sRGB/Rec.709
Gamut
|
Comments
|
|
Brightness Decrease
at a 30 degree Viewing Angle
|
27
percent Brightness Decrease
Small
Decrease
Very Good
|
Most screens become less bright when
tilted.
OLED decrease is due to optical
absorption.
LCD decrease is generally greater than 50
percent.
|
|
Contrast Ratio at 0 lux
at a 30 degree Viewing Angle
|
Infinite
Contrast Ratio
Outstanding
|
A measure of screen readability when the
screen
is tilted under low ambient lighting.
|
|
White Point Color Shift
at a 30 degree Viewing Angle
|
Small
White Point Color Shift
Δ(u’v’)
= 0.0080
2.0 JNCD
Excellent
|
JNCD is a Just Noticeable Color Difference.
See Figure 2 for the
definition of JNCD.
|
|
Primary Color Shifts
Largest Color Shift for R,G,B
at a 30 degree Viewing Angle
|
Largest Primary Color Shift
Δ(u’v’)
= 0.0278 for Pure Red
7.0 JNCD Very Good
|
JNCD is a Just Noticeable Color Difference.
See Figure 2 for the
definition of JNCD.
Largest Error Scale same as Absolute Color
Accuracy.
|
|
Color Shifts for Color Mixtures
at a 30 degree Viewing Angle
Reference Brown (255, 128, 0)
|
Small
Color Mixture Color Shift
Δ(u’v’)
= 0.0135
3.4 JNCD Very Good
|
JNCD is a Just Noticeable Color Difference.
Color Shifts for non-IPS LCDs are about 10
JNCD.
Reference Brown is a good indicator of
color shifts
with angle because of unequal drive
levels and
roughly equal luminance contributions
from Red
and Green. See Figure 2 for the definition
of JNCD.
|
|
Display Power Consumption
The display power was measured using a Linear
Regression between Luminance and AC Power with a fully charged battery.
Since the displays all have different screen sizes
and maximum brightness, the values were also scaled to the
same screen brightness (Luminance) and same screen
area in order to compare their Relative Power Efficiencies.
Below we compare the Relative Display
Power Efficiencies of the Galaxy S6 with the Galaxy S5 and iPhone 6
Smartphones.
Comparison with the Galaxy S5:
The Galaxy S6 is 20 percent more power
efficient than the Galaxy S5 (for the same Luminance and same screen area).
Comparison with LCDs and the
iPhone 6 and iPhone 6 Plus:
While LCDs remain more power efficient for images with
mostly full screen white content (like all text screens, for example),
OLEDs are now more power efficient for mixed image
content because they are emissive displays so their power varies with the
Average Picture Level (average Brightness) of the image
content. For LCDs the display power is fixed and independent of image
content.
The Galaxy S6 is in fact 23 percent more power
efficient than the iPhone
6 and iPhone 6 Plus for mixed image content (that includes
text together with photos, videos, and movies, for
example) with a typical 50 percent Average Picture Level, APL. OLEDs have
been
rapidly improving in their power efficiency. The
balance point has now moved all the way up to 65 percent APL: the OLED Galaxy
S6
is more power efficient for all APLs from zero up
through 65 percent, and the iPhone 6 and iPhone 6 Plus LCDs are more power
efficient for APLs above 65 percent.
|
|
Categories
|
Galaxy
S5
|
Galaxy
S6
|
Comments
|
|
Average Display Power
Maximum Brightness at
50% Average Picture Level
|
0.82 watts
386 cd/m2
|
0.65 watts
371 cd/m2
|
This measures the average display power
for
a wide range of image content.
|
|
Maximum Display Power
Full White Screen
at Maximum Brightness
|
1.50 watts
351 cd/m2
|
1.20 watts
348 cd/m2
|
This measures the display power for a
screen
that is entirely Peak White.
|
|
|
|
|
|
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About the Author
Dr. Raymond Soneira is
President of DisplayMate Technologies Corporation of Amherst, New Hampshire,
which produces display calibration, evaluation, and diagnostic products for
consumers, technicians, and manufacturers. See www.displaymate.com. He is a research
scientist with a career that spans physics, computer science, and television
system design. Dr. Soneira obtained his Ph.D. in Theoretical Physics from
Princeton University, spent 5 years as a Long-Term Member of the world famous
Institute for Advanced Study in Princeton, another 5 years as a Principal
Investigator in the Computer Systems Research Laboratory at AT&T Bell
Laboratories, and has also designed, tested, and installed color television
broadcast equipment for the CBS Television Network Engineering and Development
Department. He has authored over 35 research articles in scientific journals in
physics and computer science, including Scientific American. If you have any
comments or questions about the article, you can contact him at dtso.info@displaymate.com.
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Article Links: Galaxy S5
OLED Display Technology Shoot-Out
Article Links: Galaxy
Note 4 OLED Display Technology Shoot-Out
Article Links: Absolute
Color Accuracy Display Technology Shoot-Out
Article Links: Display Technology Shoot-Out
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