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OLED Tablet Display Technology Shoot-Out

Samsung Galaxy Tab S 8.4  –  Samsung Galaxy Tab S 10.5

 

Dr. Raymond M. Soneira

President, DisplayMate Technologies Corporation

 

Copyright © 1990-2014 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

 

 

Galaxy Tab S 10.5

 

Introduction

The key element for a great Tablet has always been a truly innovative and top performing display, and the best leading edge Tablets have always flaunted their beautiful high tech displays. But Tablet displays are more challenging to produce because their large screens are 3 to 4 times the size of a Smartphone. Up until now Tablets have been almost exclusively LCD based – so while the Samsung Galaxy series of Smartphones are Flagship models for Samsung to show off its latest and greatest OLED displays and display technology, there haven’t been any OLED Tablets until now (except for a single 7.7 inch OLED model launched in 2012).

 

With the continuing advancement in manufacturing OLED displays Samsung has now produced the Galaxy Tab S series, which true to form, will be the Flagship models for their line of Tablets – with display performance widely expected to be comparable to the OLED Galaxy S5, which is the best Smartphone display that we have ever tested. Samsung provided DisplayMate Technologies with pre-release production units of the Galaxy Tab S Tablets so that we could perform our well known objective and comprehensive display Lab tests, measurements, and analysis, explaining the in-depth OLED display performance results for consumers, reviewers, and journalists.

 

The Display Shoot-Out

To examine the performance of the Galaxy Tab S OLED Displays we ran our in-depth series of Mobile Display Technology Shoot-Out Lab tests and measurements in order to determine how 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 four 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 Display Shoot-Out Comparison Table summarizes the Lab measurements in the following categories:  Screen ReflectionsBrightness and ContrastColors and IntensitiesViewing AnglesOLED SpectraDisplay Power. You can also skip these Highlights and go directly to the Conclusions.

 

State-of-the-Art OLED Displays

Our extensive Lab tests and measurements presented in the detailed Comparison Table indicate that the Galaxy Tab S Tablet displays are (not surprisingly) almost identical in display performance to the OLED Galaxy S5 Smartphone that we recently tested and found to be the Best Performing Smartphone Display. See the Galaxy S5 article for additional background information on OLED displays. For direct performance comparisons with the leading LCD Tablets see our Flagship Tablet and Mini Tablet Display Shoot-Outs.

 

2.5K Quad HD 2560x1600 Displays

Both Galaxy Tab S models offer Quad HD 2560x1600 pixel displays, currently the highest resolution for Tablets, with 4.1 Mega Pixels, double the number on your HDTV. The 10.5 inch model has RGB Stripe Pixels with 287 pixels per inch, and the 8.4 inch model has Diamond Pixels and Sub-Pixel Rendering with 361 pixels per inch (ppi). Both are higher than can be resolved with normal 20/20 Vision at the typical viewing distances for Tablets, so the displays appear perfectly sharp.

 

Multiple Screen Modes and Color Management

Most Smartphones and Tablets 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 light levels. An important capability provided by the OLED Galaxy Smartphones and new Tab S Tablets is the implementation of Color Management that provides a number of Screen Modes with different levels of user selectable color saturation and display calibration based on user and application preferences. The Galaxy Tab S models have 4 user selectable Screen Modes: Adaptive Display, AMOLED Photo, AMOLED Cinema, and the Basic screen mode, which matches the sRGB/Rec.709 Standard used for most consumer content. See this Figure for the Color Gamuts of the different Screen modes and the Colors and Intensities section for measurements and details.

 

Adaptive Display Mode and 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 higher color saturation, with 138 percent of the standard sRGB/Rec.709 Gamut, the highest that we have ever measured for Tablets and Smartphones. Some people like vibrant colors, plus it is useful for special applications and particularly for viewing in medium to high levels of ambient light, because it offsets some of the reflected glare that washes out the on-screen colors.

 

AMOLED Photo Mode with Adobe RGB Gamut

Most high-end digital cameras have an option to use the Adobe RGB Gamut, which is 17 percent larger than the standard sRGB/Rec.709 Gamut used in consumer cameras. The AMOLED Photo screen mode on the Galaxy Tab S provides an 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 mode for the Galaxy Tab S is 3.2 JNCD, which is very accurate. See this Figure for an explanation and visual definition of JNCD and Color Accuracy Plots showing the measured 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 Color Accuracy Plots for measurements and details.

 

Basic Mode with sRGB / Rec.709 Standard Gamut

The Basic screen mode provides the most accurate Color and White Point calibration for the standard sRGB/Rec.709 Color Gamut that is used in virtually all current consumer content for digital cameras, HDTVs, the internet, and computers, including photos, videos, and movies. The Absolute Color Accuracy for the Basic screen mode is an Excellent 2.1 JNCD, the most color accurate display that we have ever measured for a Smartphone or Tablet. See this Figure for an explanation and visual definition of JNCD and Color Accuracy Plots showing the measured Color Errors, 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 Color Accuracy Plots for measurements and details.

 

Screen Brightness

Both of the Galaxy Tab S displays have Very Good to Excellent screen Brightness, but are not as bright as the brightest LCD Tablets. The current record holder for Tablets is the Nokia Lumia 2520 with 684 cd/m2 (nits), while the Tab S has 546 nits with Automatic Brightness On and 415 nits under manual Brightness (10 percent lower for mixed content with 50 percent Average Picture Level APL and 25 percent lower for an all white 100 percent APL screen). High screen Brightness is only needed for High Ambient Light, so turning Automatic Brightness On will provide better screen visibility and also a longer battery running time. As discussed below, the record low screen Reflectance of 4.7 percent for the Galaxy Tab S further improves its effective Screen Brightness in high Ambient Light. See the Brightness and Contrast section for measurements and details.

 

Super Dimming Mode

The Galaxy Tab S Tablets also have a Super Dimming Mode that allows the Maximum Screen Brightness to be set all the way down to just 2 cd/m2 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.

 

Performance in High Ambient Lighting

Mobile displays are often used under relatively bright ambient light, which washes out 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 Tab S displays have both. They have 4.7 percent Screen Reflectance, the lowest of any Tablet display that we have ever tested. 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 Tab S have a Contrast Rating for High Ambient Light that ranges from 59 to 116, among the highest that we have ever measured. See the Brightness and Contrast section for measurements and details.

 

Power Efficiency

LCDs are typically more power efficient for images with mostly white content (like text screens, for example), while OLEDs are 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 independent of image content. OLEDs have been rapidly improving in their power efficiency. For example, comparing the OLED Tab S 8.4 to the LCD Apple iPad Air: the OLED Tab S with Diamond Pixels is 27 percent more power efficient (for the same screen size and Luminance) than the LCD iPad Air for mixed image content (that includes photos, videos, and movies, for example) with a typical 50 percent Average Picture Level. See the Display Power section for more details. The Galaxy Tab S displays also have 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.

 

Screen Uniformity

One subtle but important advantage of OLEDs is their excellent screen uniformity compared to LCDs, which often show hot spots and shadows from the edge LED lighting.

 

Viewing Angle Performance

While Tablets 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’s 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 Tab S displays show a much smaller 21 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 Tab S Basic screen mode provides very nice, pleasing and accurate colors, and picture quality. Although the Image Contrast and Color Saturation are 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. The Adaptive Display screen mode has significantly more vibrant and saturated colors. Some people like that. It is also particularly recommended for medium to high levels of ambient light viewing because it offsets some of the reflected glare that washes out the images.

 

 

Galaxy Tab S Conclusions:   An Impressive Tablet Display…

The primary goal of this Display Technology Shoot-Out article series has always been to point out which manufactures and display technologies are leading and advancing the state-of-the-art of displays by performing comprehensive and objective 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 measurements that we also publish, so that everyone can judge the data for themselves as well…

 

Best Tablet Display:  Based on our extensive Lab tests and measurements, the Galaxy Tab S is the Best Performing Tablet Display that we have ever tested, not surprisingly with performance that is almost identical to the OLED Galaxy S5 Smartphone that we recently tested and found to be the Best Performing Smartphone Display. The Galaxy Tab S establishes new records for best Tablet display performance in: Highest Color Accuracy, Infinite Contrast Ratio, Lowest Screen Reflectance, and smallest Brightness Variation with Viewing Angle. Both Galaxy Tab S models offer Quad HD 2560x1600 pixel displays (with 287 to 361 pixels per inch), currently the highest for Tablets, with 4.1 Mega Pixels, double the number on your HDTV. Where the Galaxy Tab S does very well but does not break performance records is in maximum display Brightness – the current record holder for Tablets is the Nokia Lumia 2520 with 684 nits, while the Tab S has 546 nits with Automatic Brightness On and 415 nits under manual Brightness (10 percent lower for mixed content with 50 percent Average Picture Level APL and 25 percent lower for an all white screen). High screen Brightness is only needed for High Ambient Light, so turning Automatic Brightness On will provide better screen visibility and also a longer battery running time. Its record low Screen Reflectance of 4.7 percent further improves the effective screen Brightness, resulting in a very high Contrast Rating for High Ambient Light with Automatic Brightness On. See the Brightness and Contrast section for details. Comparisons with the leading LCD Tablets are examined below.

 

Multiple Screen Modes and Color Management:  Most Tablets 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 light levels. Samsung’s implementation of Color Management for their OLED Smartphones and Tablets allows them to provide multiple Screen Modes with different Color Gamuts and color calibrations – other Tablets only provide a single fixed screen Color Gamut and calibration.

 

Most Accurate Colors:  The Galaxy Tab S Basic screen mode has the most accurate colors for standard (sRGB/Rec.709) consumer content of any Smartphone or Tablet display that we have ever measured (even slightly better than the Galaxy S5 the previous record holder – also see this regarding Bogus Color Accuracy Measurements). 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.

 

Adobe RGB AMOLED Photo Mode:  Most high-end digital cameras have an option to use the Adobe RGB Gamut, which is 17 percent larger than the standard sRGB/Rec.709 Gamut used in consumer cameras. The AMOLED Photo screen mode on the Galaxy Tab S provides an accurate calibration to the Adobe RGB standard, which is rarely available in consumer displays, and is very useful for high-end digital photography and other advanced imaging applications. The large screens on the Galaxy Tab S makes them especially useful for photographers to check their Adobe RGB photo shots and for showing them off.

 

Adaptive Display Wide Color Gamuts:  The OLED display’s native Wide Color Gamut in the Adaptive Display screen mode has significantly more vibrant and saturated colors, with 138 percent of the standard sRGB/Rec.709 Color Gamut, the highest that we have ever measured for Tablets and Smartphones. Some people like vibrant colors, plus it is useful for special applications and particularly for medium to high levels of ambient light viewing because it offsets some of the reflected glare that washes out the on-screen colors.

 

Comparisons with the Amazon Kindle Fire HDX and Apple iPad Tablet Displays:  In 2013 the Amazon Kindle Fire HDX Tablets became the top performing Tablet displays in our Display Technology Shoot-Out series, leapfrogging the competition with cutting edge displays using Quantum Dots and Low Temperature Poly Silicon. But with the ever continuing and impressive improvements in display technology the Samsung Galaxy Tab S has now taken the lead for the Best Tablet Displays. The Apple iPad Air, which came in second after the Kindle Fire HDX 8.9, now moves into third place for Flagship Tablet models, and the iPad mini with Retina Display, with a very disappointing 63 percent of the standard sRGB/Rec.709 Color Gamut and poor Color Accuracy moves further down the pack for the Mini Tablet models. You can directly compare all of the display performance measurements and results by referring to these and other articles in our Display Technology Shoot-Out article series.

 

The Next Generation of Displays:  With display technology advancing rapidly on many different fronts things can change again in the next generation of displays for Tablets and Smartphones. So a strong Congratulations to Samsung, but please don’t rest on your laurels – and best wishes to all manufacturers in developing their next generation of even higher performance displays!!

 

The most important developments for the upcoming generations of both OLED and LCD mobile displays will come from improvements in their image and picture quality in ambient light, which washes out screen images, resulting in reduced readability, image contrast, and color saturation and accuracy. The key will be in dynamically changing the display’s color management and intensity scales with the measured Ambient Light in order to automatically compensate for reflected 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 and technologies that succeed in implementing this new strategy will take the lead in the next generations of mobile 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 Tab S 10.5

 

 

Display Shoot-Out Comparison Table

Below we examine in-depth the OLED displays on the Samsung Galaxy Tab S 8.4 and 10.5 models based on objective Lab measurement data and criteria. For comparisons and additional background information see the Galaxy S5 OLED Display Technology Shoot-Out, the Flagship Tablet LCD Display Technology Shoot-Out, and the Mini Tablet LCD Display Technology Shoot-Out. For comparisons with the other leading Tablet, Smartphone and Smart Watch displays see our Mobile Display Technology Shoot-Out series.

 

Categories

Samsung Galaxy Tab S 8.4

Samsung Galaxy Tab S 10.5

Comments

Display Technology

 8.4 inch

OLED with Diamond Pixels

 10.5 inch

OLED with RGB Stripe Pixels

Organic Light Emitting Diode

Sub-Pixels are in a Diamond or an RGB Stripe

Screen Shape

 16:10 = 1.60

Aspect Ratio

 16:10 = 1.60

Aspect Ratio

The Galaxy Tab S has the same shape as

widescreen HDTV video content.

Screen Area

31.4 Square Inches

49.7 Square Inches

A better measure of size than the diagonal length.

Relative Screen Area

100 percent

158 percent

Relative Screen Area for the Tablets

Display Resolution

 2560 x 1600 pixels

2.5K  Quad HD

 2560 x 1600 pixels

2.5K  Quad HD

Screen Pixel Resolution.

Quad HD can display four 1280x720 HD images

Total Number of Pixels

 4.1 Mega Pixels

 4.1 Mega Pixels

Total Number of Pixels.

Pixels Per Inch

 361 PPI with Diamond Pixels

Excellent

287 PPI with RGB Stripe 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

    Red  255 SPPI

 Green  361 SPPI

   Blue  255 SPPI

    Red 287 SPPI

 Green 287 SPPI

   Blue 287 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  2,048 KSP

   Green 4,096 KSP

     Blue 2,048 KSP

     Red  4,096 KSP

   Green 4,096 KSP

     Blue 4,096 KSP

Number of Kilo Sub-Pixels KSP for Red, Green, Blue.

Diamond Pixel displays have only half the number of

Red and Blue Sub-Pixels as standard RGB displays.

At High PPI this is generally not visible due to the

use of Sub-Pixel Rendering.

20/20 Vision Distance

where Pixels or Sub-Pixels

are Not Resolved

    9.5 inches for White and Green

         13.4 inches for Red and Blue

      12.0 inches for White and Green

 12.0 inches for Red and Blue

For 20/20 Vision the minimum Viewing Distance

where the screen appears perfectly sharp to the eye.

At 14 inches from the screen 20/20 Vision is 246 PPI.

Display Sharpness

at Typical Viewing Distances

Display appears Perfectly Sharp

Pixels are not Resolved with 20/20 Vision

at Typical Viewing Distances of

12 to 15 inches

 

The Sub-Pixel Rendering significantly improves Display Sharpness

Display appears Perfectly Sharp

Pixels are not Resolved with 20/20 Vision

at Typical Viewing Distances of

15 to 18 inches

 

 

 

The Typical Viewing Distances for these Tablets

are in the range of 12 to 18 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

Yes

Typical Viewing Distances are 12 to 18 inches

or more.

Photo Viewer Color Depth

 Full 24-bit Color

No Dithering Visible

256 Intensity Levels

 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 Tab S do 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 ReflectionsBrightness and ContrastColors and IntensitiesViewing AnglesOLED SpectraDisplay Power.

 

The Galaxy Tab S line has 4 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 camera, photo, video,

movie, web, and computers.

 

Both Tablets have the same

4 Screen Modes. Three were selected for the article tests.

Galaxy Tab S 8.4

 

Adaptive Display

Wide Color Gamut

Galaxy Tab S 10.5

Comments

AMOLED Photo mode

Adobe RGB Gamut

Basic mode

sRGB/Rec.709 Gamut

Viewing Tests

in Subdued Ambient Lighting

 

Good Images

Photos and Videos

have too much color

and accurate contrast

 

Wide Color Gamut Mode

Intentionally Vivid Colors

Very Good Images

Adobe RGB Photos

have very good color

and accurate contrast

 

Accurate Pro Photo Mode

 

Very Good Images

Photos and Videos

have very good 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 Tab S displays have 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 Tab S OLED Displays 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

Very Good 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

Tablets 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

Very Good Calibration

Accurate Pro Photo Mode

Excellent Calibration

Accurate Std Mode

Galaxy Tab S displays have 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 Tab S Display Grade is Excellent A

The Best Performing Tablet Displays that we have ever tested.

The Galaxy Tab S displays deliver excellent

image quality, have both Color Accurate and

Wide Color Gamut Vivid Color modes, have

high Screen Brightness and low Reflectance,

have good Viewing Angles, and are all around

top performing Tablet displays.

 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 Tablets 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 on each Galaxy Tab S model.

 

The Galaxy Tab S has the Lowest Reflectance that we have ever measured for a Tablet.

 

Galaxy Tab S 8.4

Galaxy Tab S 10.5

Comments

Average Screen Reflection

Light From All Directions

 4.7 percent

Ambient Light Reflections

Excellent

 4.7 percent

Ambient Light Reflections

Excellent

Measured using an Integrating Hemisphere and

a Spectroradiometer. The best value we have

ever measured for a Tablet is 4.7 percent.

Mirror Reflections

Percentage of Light Reflected

7.6 percent

for Mirror Reflections

Very Good

7.5 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.

 

Both Tablets have the same

4 Screen Modes. Three were selected for the article tests.

Galaxy Tab S 8.4

 

Adaptive Display

Wide Color Gamut

Galaxy Tab S 10.5

Comments

AMOLED Photo mode

Adobe RGB Gamut

Basic mode

sRGB/Rec.709 Gamut

Measured Brightness

50% Average Picture Level

Brightness 328 cd/m2

Very Good

Brightness 301 cd/m2

Very Good

Brightness 301 cd/m2

Very Good

This is the Brightness for typical screen content

that has a 50% Average Picture Level.

Measured Brightness

100% Full Screen White

Brightness 286 cd/m2

Good

Brightness 279 cd/m2

Good

Brightness 280 cd/m2

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 415 cd/m2

Very Good

Brightness 364 cd/m2

Very Good

Brightness 364 cd/m2

Very Good

This is the Peak Brightness for a screen that

has only a tiny 1% Average Picture Level.

Measured Brightness

with Automatic Brightness On

Brightness

349 – 544 cd/m2

Excellent

Brightness

366 – 518 cd/m2

Excellent

Brightness

366 – 518 cd/m2

Excellent

Some displays including the Galaxy S5 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

61 – 88

Very Good

 

74 – 116

With Auto Brightness

Excellent

59 – 77

Very Good

 

 78– 110

With Auto Brightness

Excellent

 60 – 77

Very Good

 

78 – 110

With Auto Brightness

Excellent

Depends on the Screen Reflectance and Brightness.

Defined as Maximum Brightness / Average Reflectance.

 

Some displays including the Galaxy Tab S 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

 

Figure 1

Color Gamuts

Click to Enlarge

 

Figure 2

Color Accuracy

Click to Enlarge

 

Figure 3

Intensity Scale

Click to Enlarge

 

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 Tab S Screen Modes that we tested are calibrated for different applications and user preferences.

Both Tablets have the same

4 Screen Modes. Three were selected for the article tests.

Galaxy Tab S 8.4

 

Adaptive Display

Wide Color Gamut

Galaxy Tab S 10.5

Comments

AMOLED Photo mode

Adobe RGB Gamut

Basic mode

sRGB/Rec.709 Gamut

Color of White

Color Temperature in degrees

 

Measured in the dark at 0 lux

See Figure 1

7,468 K

White is Somewhat Bluish

Intentionally Bluish Mode

 

For Some Applications

the White Point Will Vary

with the Ambient Lighting

6,320 K

Close to Standard White

Accurate Pro Photo Mode

 

See Figure 1

6,326 K

Close to Standard White

Accurate Std Mode

 

See Figure 1

D65 with 6,500 K is the standard color of White

for most Consumer Content and needed for

accurate color reproduction of all images.

 

See Figure 1 for the plotted White Points.

Color Gamut

Measured in the dark at 0 lux

 

See Figure 1

 138 percent

sRGB / Rec.709

 

Colors More Saturated

Wide Color Gamut Mode

 

See Figure 1

 

106 percent

Adobe RGB

 

Close to Adobe RGB Gamut

Accurate Pro Photo Mode

 

See Figure 1

113 percent

sRGB / Rec.709

 

Slightly Too High

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’) = 0.0351

 8.8 JNCD

 

Colors More Saturated

Wide Color Gamut Mode

 

See Figure 2

 Average Color Error

From Adobe RGB

Δ(u’v’) = 0.0126

3.2 JNCD

 

Very Good Accuracy

Accurate Pro Photo Mode

 

See Figure 2

 Average Color Error

From sRGB/Rec.709

Δ(u’v’) = 0.0085

 2.1 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’) = 0.0652

16.3 JNCD for Cyan-Blue

 

Colors More Saturated

Wide Color Gamut Mode

 

See Figure 2

Largest Color Error

From Adobe RGB

Δ(u’v’) = 0.0361

9.0 JNCD for 50% Red

 

Good Accuracy

Accurate Pro Photo Mode

 

See Figure 2

Largest Color Error

From sRGB/Rec.709

Δ(u’v’) = 0.0161

4.0 JNCD for Red

 

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

31 percent Decrease

Good

23 percent Decrease

Good

23 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

Slightly Too Steep

See Figure 3

Smooth and Straight

Slightly Too Steep

See Figure 3

Smooth ad Straight

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

2.44

Gamma Slightly Too High

2.37

Gamma Slightly Too High

 2.37

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 Tablets 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 Tablets and Smartphones.

 

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 Tablet 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 on a Tablet.

Both Tablets have the same

4 Screen Modes. Three were selected for the article tests.

Galaxy Tab S 8.4

 

Adaptive Display

Wide Color Gamut

Galaxy Tab S 10.5

Comments

AMOLED Photo mode

Adobe RGB Gamut

 Basic mode

sRGB/Rec.709 Gamut

Brightness Decrease

at a 30 degree Viewing Angle

 22 percent Decrease

Small Decrease

21 percent Decrease

Small Decrease

21 percent Decrease

Small Decrease

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

Infinite Contrast Ratio

Outstanding

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 Color Shift

Δ(u’v’) = 0.0059

 1.5 JNCD

Small Color Shift

Δ(u’v’) = 0.0055

1.4 JNCD

Small Color Shift

Δ(u’v’) = 0.0056

 1.4 JNCD

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

Medium Color Shift

Largest Δ(u’v’) = 0.0327

for Red

8.2 JNCD

Medium Color Shift

Largest Δ(u’v’) = 0.0276

for Red

 6.9 JNCD

Medium Color Shift

Largest Δ(u’v’) = 0.0257 for Red

6.4 JNCD

JNCD is a Just Noticeable Color Difference.

See Figure 2 for the definition of JNCD.

 

Color Shifts for Color Mixtures

at a 30 degree Viewing Angle

Reference Brown (255, 128, 0)

Small Color Shift

Δ(u’v’) = 0.0146

3.6 JNCD

Small Color Shift

Δ(u’v’) = 0.0135

3.4 JNCD

Small Color Shift

Δ(u’v’) = 0.0117

2.9 JNCD

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.

 

 

 

Figure 4

Display Spectra

Click to Enlarge

 

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.

 

LCDs are typically more power efficient for images with mostly white content (like text screens, for example), while OLEDs

are 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 independent of image content.

 

Below we compare the Relative Power Efficiencies of the OLED Tab S displays with the LCD Apple iPad Air using data from

our Flagship Tablet Display Technology Shoot-Out. These results are all scaled for the same screen area and Luminance.

 

The OLED Tab S 8.4 with Diamond Pixels is 27 percent more power efficient than the LCD Apple iPad Air for mixed

image content (that includes photos, videos, and movies, for example) with a typical 50 percent Average Picture Level.

Alternatively, the OLED Tab S 8.4 is more power efficient than the LCD iPad Air for Average Picture Levels below 69 percent,

while the LCD iPad Air is more power efficient for Average Picture Levels greater than 69 percent.

 

The OLED Tab S 8.4 with Diamond Pixels is 32 percent more power efficient than the OLED Tab S 10.5 with RGB Stripe Pixels.

 

So the OLED Tab S 10.4 is more power efficient than the LCD iPad Air for Average Picture Levels below 47 percent and

the LCD iPad Air is more power efficient for Average Picture Levels greater than 47 percent.

 

 

Galaxy Tab S 8.4

Galaxy Tab S 10.5

Comments

Average Display Power

Maximum Brightness at

50% Average Picture Level

1.75 watts

328 cd/m2

3.60 watts

301 cd/m2

This measures the average display power for

a wide range of image content.

Maximum Display Power

Full White Screen

at Maximum Brightness

3.10 watts

286 cd/m2

7.00 watts

280 cd/m2

This measures the display power for a screen

that is entirely Peak White.


 

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.

 

DisplayMate Display Optimization Technology

All Smartphone and Tablets 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.

 

About DisplayMate Technologies

DisplayMate Technologies specializes in proprietary advanced scientific display calibration and mathematical display optimization to deliver unsurpassed objective performance, picture quality and accuracy for all types of displays including video and computer monitors, projectors, HDTVs, mobile displays such as smartphones and tablets, and all display technologies including LCD, OLED, 3D, LED, LCoS, Plasma, DLP and CRT. This article is a lite version of our intensive scientific analysis of Smartphone and Smartphone mobile displays – before the benefits of our advanced mathematical DisplayMate Display Optimization Technology, which can correct or improve many of the display deficiencies. We offer DisplayMate display calibration software for consumers and advanced DisplayMate display diagnostic and calibration software for technicians and test labs.

 

For manufacturers we offer Consulting Services that include advanced Lab testing and evaluations, confidential Shoot-Outs with competing products, calibration and optimization for displays, cameras and their User Interface, plus on-site and factory visits. We help manufacturers with expert display procurement, prototype development, and production quality control so they don’t make mistakes similar to those that are exposed in our Display Technology Shoot-Out series. See our world renown Display Technology Shoot-Out public article series for an introduction and preview. DisplayMate’s advanced scientific optimizations can make lower cost panels look as good or better than more expensive higher performance displays. If you are a display or product manufacturer and want to turn your display into a spectacular one to surpass your competition then Contact DisplayMate Technologies to learn more.

 

 

Article Links:  Galaxy S5 OLED Display Technology Shoot-Out

Article Links:  Flagship Tablet LCD Display Technology Shoot-Out

Article Links:  Mini Tablet LCD Display Technology Shoot-Out.

 

Article Links:  Mobile Display Shoot-Out Article Series Overview and Home Page

Article Links:  Display Technology Shoot-Out Article Series Overview and Home Page

 

 

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