OnePlus 8T Display Technology Shoot-Out

 

Dr. Raymond M. Soneira

President, DisplayMate Technologies Corporation

 

Copyright © 1990-2020 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

 

 

 

Introduction and Overview

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 is the display performance that determines how good and how beautiful everything on the Smartphone looks, including the camera photos, videos, movies, web content, plus all of your Apps, and also how readable and how usable the screen is in High Ambient Lighting. The Display is the Crown Jewel of the Smartphone!

 

In this Display Technology Shoot-Out article series we Only Test and Only Cover the Very Best State-of-the-Art Top Performing Top Tier Smartphone Displays. The articles are designed to promote Superior Display Performance so that consumers, reviewers, and journalists all Recognize and Appreciate Display Excellence, and also to reward and encourage manufacturers to produce top performing displays for their products.

 

All of the DisplayMate Display Performance Grades, Ratings and Awards are based Entirely on the extensive objective Lab Tests and Measurements that we also publish, so that everyone can judge and compare the display performance data for themselves as well. As Display Performance continues to improve each year we have and will continue to raise the Performance Levels necessary to receive a DisplayMate Best Smartphone Display Award and A+ Display Rating. As a result, only the Very Best Displays will continue to receive A+ Ratings each year.

 

This is an independent scientific objective Lab test and analysis of OLED displays written for consumers, reviewers, and journalists. It is the latest edition in our ten year article series that has Lab tested, tracked and analyzed the development of mobile OLED displays and display technology, from its early beginnings in 2010, when OLED displays started out in last place, into a rapidly improving and evolving display technology that now has a commanding first place lead and continues pushing ahead aggressively..

 

The Move to OLED Displays

LCDs are a great cutting edge high performance display technology for Tablets to TVs, but for small handheld Smartphones, OLED displays provide a number of major advantages over LCDs including: being much thinner, much lighter, without needing a bezel, with a rimless edge-to-edge full screen design. They can be made flexible and into curved screens, plus they have very fast response times, better viewing angles, and can provide always-on display modes.

 

The very fast Response Times of OLED displays makes the new Higher 120 Hz Screen Refresh Rate possible, which improves image Scrolling and Videos, plus Motion and Gaming Performance in Apps.

 

Many of the OLED performance advantages result from the fact that every single sub-pixel in an OLED display is independently directly electrically powered to emit light, so only the active image sub-pixels draw power based on their individual brightness levels. OLEDs can also provide better color accuracy, image contrast accuracy, and screen uniformity because the irregularities and variations in LCD Backlights introduce color and brightness irregularities and variations over the screen.

 

As the result of their very versatile power management capabilities, OLEDs are not only more power efficient than LCDs for most image content, but they now deliver much higher Peak Brightness than LCDs because the maximum power can be delivered to just the sub-pixels that are needed for producing the current image. However, for mostly all white screen content, LCDs are likely to remain brighter and more power efficient for a while.

 

Some of the OnePlus 8T Display Performance Highlights

These are only a few of the OnePlus 8T Display Performance Highlights that we will be covering in detail throughout the article:

 

· Very High Absolute Color Accuracy (0.5 JNCD) that is Visually Indistinguishable From Perfect.

 

· Very High Image Contrast Accuracy and Intensity Scale Accuracy that is Visually Indistinguishable From Perfect.

 

· High Brightness Mode (up to 1,090 nits) in High Ambient Light.

 

· Peak Brightness, Color Accuracy, Contrast Accuracy and Intensity Scales that are Independent of the on-screen Average Picture Level APL.

 

· Small Shifts in Brightness and Color with Viewing Angle, including White, which is the most common background color.

 

· OnePlus 8T sets or matches 11 Smartphone Display Performance Records, earning DisplayMate’s highest ever A+ grade.

 

Comparison of the OnePlus 8T with the OnePlus 8 and OnePlus 8 Pro

The OnePlus 8T is an enhanced version of the OnePlus 8 that includes some display functions and features found on the OnePlus 8 Pro.

 

· Improved 120 Hz Display Refresh Rate compared to the 90 Hz Refresh Rate on the OnePlus 8.

 

· Improved Display Calibration Color Accuracy and Image Contrast Accuracy.

 

· Improved High Brightness Mode Luminance Accuracy.

 

You can compare their display performance in detail by using a Tabbed web browser with our DisplayMate Display Technology Shoot-Out articles for each model.

 

OnePlus 8T Conclusion Summary

Below is the OnePlus 8T Display Performance Summary from the Conclusion section:

 

All of the DisplayMate Display Performance Grades, Ratings and Awards are based Entirely on the extensive objective Lab Tests and Measurements that we also publish, so that everyone can judge and compare the display performance data for themselves as well.

 

Based on our extensive Lab Tests and Measurements the OnePlus 8T has a Very Impressive Excellent Top Tier World Class Smartphone Display with close to Text Book Perfect Calibration Accuracy and Performance that is Visually Indistinguishable From Perfect. Based on our objective Lab Tests and Measurements the OnePlus 8T receives a DisplayMate Best Smartphone Display Award earning DisplayMate’s highest ever Display Performance Grade of A+ and setting or matching 11 Smartphone Display Performance Records. As a result OnePlus 8T joins the very select Top Tier of the Best Smartphone Displays.

 

Article Overview

This OnePlus 8T article has the following major sections:

 

· Highlights:  The Display Highlights and Performance Results section below has detailed information, explanations, and analysis.

 

· Features:  The Display Performance Functions and Features section lists the main functions and features.

 

· Conclusions:  The OnePlus 8T Conclusions section summarizes all of the Results, Features, Functions and Records.

 

· Records:  The Display Performance Records section lists the Lab measurement performance records.

 

· DisplayMate A+ Rating:  The Display Rating section summarizes the Display Ratings and Criteria.

 

· DisplayMate Award:  The Best Smartphone Display Award section summarizes the DisplayMate Display Performance Award Criteria.

 

· Measurements:  The Display Shoot-Out Lab Measurements Comparison Table has the complete set of measurements and tests.

 

· Assessments:  The Display Performance Assessments section summarizes the display evaluation details.

 

· Future of OLED:  The Future of OLED Smartphones examines the evolution of OLED displays.

 

· The Next Generation:  Improving the Next Generation of Mobile Displays

 

· Performance in Ambient Light:  Improving Display Performance for Real World Ambient Light

 

We’ll cover all of the these display performance topics and much more, with in-depth expert comprehensive display tests, measurements and analysis that you will find nowhere else.

 

The Display Shoot-Out

To examine the performance of the OnePlus 8T OLED Display 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 see our 2010 Smartphone Display Shoot-Out, and for a real history lesson see our original 2006 Smartphone Display Shoot-Out.

 

OnePlus provided DisplayMate Technologies with a pre-announcement production unit of the OnePlus 8T so that we could perform our well known objective and comprehensive DisplayMate Lab tests, measurements, and analysis, explaining in-depth the display performance results for consumers, reviewers, and journalists as early as possible.

 

 

 

 

OnePlus 8T Display Highlights and Performance Results

In this section we review and explain the principal results from the extensive DisplayMate Lab Tests and Measurements

in the following categories:  Display Specifications,  Overall Assessments,  Screen Reflections,  Brightness and Contrast,

Colors and Intensities,  Absolute Color Accuracy,  Viewing Angles,  OLED Spectra,  Display Power.

 

Display Lab Tests and Measurement Data Table

See the Display Shoot-Out Lab Measurements Comparison Table below for the complete set of DisplayMate Lab Tests and Measurements.

 

Main Topics Covered

This Display Highlights and Performance Results section has detailed information, explanations, and analysis on the OnePlus 8T Display for the Main Topics listed below.

You can skip this section and go directly to the OnePlus 8T Conclusions for a Summary of the Display Test and Performance Results.

 

· State-of-the-Art OLED Display

 

· Large Full Screen Display

 

· Front Camera Punch-hole

 

· 3K High Resolution Display

 

· Diamond Pixels

 

· Higher 120 Hz Screen Refresh Rate

 

· Selectable Color Gamuts and Screen Calibration Modes

 

· Industry Standard Color Gamuts

 

· Automatic Color Management

 

· Very High Contrast Accuracy and Intensity Scale Accuracy

 

· Peak Brightness that is Independent of the on-screen Image Content

 

· Color Accuracy and Intensity Scales that are Independent of the Image Content

 

· Natural Mode with Very High Absolute Color Accuracy

 

· Vivid Mode with Vibrant Colors and Contrast

 

· Advanced AMOLED Wide Gamut Mode

 

· Advanced Modes with User Adjustable White Points

 

· Advanced AMOLED Wide Gamut Mode in Ambient Light

 

· High Screen Brightness and Performance in High Ambient Light

 

· High Brightness Mode

 

· High Dynamic Range Mobile HDR10+ Display

 

· Viewing Angle Performance

 

· Vision Comfort Night Mode with Reduced Blue Light

 

· Super Dim Setting

 

· Dark Mode

 

· Viewing Tests Performance

 

· Display Power Efficiency

 

· State-of-the-Art OLED Display

The OnePlus 8T has a State-of-the-Art Full Screen Flexible OLED display panel from Samsung Display, which produces most of the Top Tier Smartphone displays for leading manufacturers. While the OLED display itself is flexible, the screen remains rigid under an outer hard cover glass. The very fast Response Times of the OLED display makes the new Higher 120 Hz Screen Refresh Rate possible, which improves image Scrolling and Videos, plus Motion and Gaming Performance in Apps.

 

· Large 6.55 inch Full Screen Display with a Wide Aspect Ratio of 20 : 9

The OnePlus 8T has a large 6.55 inch State-of-the-Art OLED display that almost fills the entire front face of the phone from edge-to-edge.

 

The display also has a new form factor with a taller height to width Aspect Ratio of 20 : 9 = 2.22, which is 25% larger than the 16 : 9 = 1.78 on most Smartphones (and widescreen TVs) because the display now has the same overall shape as the entire phone. It is taller in Portrait mode and wider in Landscape mode. This provides extra space for Notifications and for displaying multiple Apps and content simultaneously on-screen side-by-side.

 

· Front Camera Punch-hole

Minimizing the thickness of any bezels and borders that appear around the display is now a major priority for both consumers and manufacturers.

 

The major challenge has been minimizing the space required for the various sensors, camera and speaker on the front of the phone. In the past the approach was to reserve a black border area along the entire top edge of the phone. This resulted in an increased overall size of the phone, so a new approach was to let the display fill the front face of the phone, but then cut out a middle slot at its very top for the camera, sensors and speaker. However, this then significantly cuts into the standard rectangular shape of the display, and eliminates some the image content that is supposed to appear there, including photos, videos, and Apps.

 

Instead, the OnePlus 8T display has a very small circular Punch-hole at the very top of the screen for the front facing selfie camera and sensors. The Front Camera Punch-hole is just 3.9mm in diameter, and it takes up only a tiny 0.1% of the total display area, a key factor in the high 92% Screen-to-Body Ratio for the OnePlus 8T.

 

The Punch-hole is implemented as a clear window opening within the OLED display, something that cannot be done with LCD technology because of its embedded Liquid Crystal. The Punch-hole appears as a very sharp very well defined circle because of the fine Diamond Sub-Pixel structure of the OLED display.

 

· 2K+ High Resolution FHD+ 2400x1080 Display with 402 pixels per inch

The OnePlus 8T has a 2K+ High Resolution Full HD+ display with 2400x1080 pixels and 402 pixels per inch, with 2.6 Mega Pixels, 25 percent more than on your HDTV.

 

The pixels per inch specification is often used as the primary marketing feature for Smartphone displays. While many Flagship models have 450 to 500+ pixels per inch, that is more than most users and most applications need for good visual sharpness and picture quality. For example, many of Apple’s Retina Displays have 326 pixels per inch. The 402 pixels per inch on the OnePlus 8T is in the middle of this range. Two key factors in producing high visual image sharpness are Diamond Pixels and Sub-Pixel Rendering, which we discuss next...

 

The OnePlus 8T display has both Diamond Pixels (see below) and Sub-Pixel Rendering, providing significantly higher image sharpness than can be resolved with normal 20/20 Vision at the typical viewing distances of 12 inches or more for Smartphones, so the display appears perfectly sharp.

 

The OnePlus 8T uses Sub-Pixel Rendering, which further improves image sharpness because the individual Red, Green and Blue Sub-Pixels are treated as independent addressable image elements and are not bound together as complete Pixels (like in most displays), so the nearest Sub-Pixel is used when rendering the image. In some cases, Sub-Pixel Rendering can make the screen appear to have up to 3 times the resolution of traditional Pixel Rendering.

 

· Diamond Pixels

A Diamond Pixel layout is used on most Smartphone OLED displays rather than an RGB Stripe pattern that is used for most LCDs. 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. In order to maximize the sub-pixel packing and achieve the highest possible pixels per inch (ppi), that leads to a Diamond rather than Square or Striped arrangement of the Sub-Pixels.

 

· Higher 120 Hz Screen Refresh Rate

Most Smartphones refresh their screens 60 times per second (Hz) or less. The OnePlus 8T has both the Normal 60 Hz Display Refresh Rate plus a New Higher 120 Hz Refresh Rate. The very fast Response Times of OLED displays makes the Higher 120 Hz Refresh Rate possible.

 

Doubling the Refresh Rate provides several important advantages, including much smoother Scrolling and Videos, plus improved Motion and Gaming Performance in Apps. In addition, some people can sense screen flicker on some Smartphone displays, which can result in visual fatigue, eye strain, and headaches. The 100% higher Refresh Rate and higher Pulse Width Modulation Rate of 480 Hz for the OnePlus 8T may reduce or eliminate this effect for some users that are affected by display flicker.

 

· Selectable Color Gamuts and Screen Calibration Modes

The OnePlus 8T provides 5 user selectable Screen Calibration modes that provide control of the Color Gamut, Vividness and Contrast of the displayed images. They are the Natural mode, which provides the most Accurate Colors and Contrast, the Vivid mode, which provides more Vibrant Colors and Contrast, and 3 Advanced modes that include: an adjustable sRGB Gamut mode, an adjustable P3 Gamut mode, and an adjustable AMOLED Wide Gamut mode that provides the Full Native Color Gamut of the OLED display.

 

Use Display Settings to switch between the Screen Calibration modes.

See this Figure for the Color Gamuts and Color Modes and the Colors and Intensities section for the measurements and details. Note that the Vivid mode is the standard and factory default Screen Calibration mode. Use Display Settings to switch between the Screen Calibration modes. We discuss each of the tested Screen Calibration modes below…

 

· Industry Standard Color Gamuts

The OnePlus 8T supports the two most important Industry Standard Color Gamuts: the sRGB / Rec.709 Color Gamut that is used for most current consumer content, and the new Wide DCI-P3 Color Gamut that is used in 4K Ultra HD TVs. The DCI-P3 Gamut is 26 percent larger than the sRGB / Rec.709 Gamut. However, Automatic Color Management provides support for a large number of other Standard and Non-Standard Color Gamuts...

 

· Automatic Color Management

Most Smartphones and Tablets generally provide only one to several fixed Color Gamuts. The OnePlus 8T Natural mode has Automatic Color Management that automatically switches to the proper Color Gamut for any displayed image content that has an ICC Profile within the OLED Wide Color Space, so images automatically appear with the correct colors, neither over-saturated or under-saturated. Automatic Color Management with multiple and varying Color Gamuts is a very useful and important state-of-the-art capability that all manufacturers will need to provide in the future.

 

· Very High Contrast Accuracy and Intensity Scale Accuracy

The Intensity Scale (sometimes called the Gray Scale) not only controls the Image and Picture Contrast within all displayed images but it also controls how the Red, Green and Blue primary colors mix to produce all of the on-screen colors. So if the Intensity Scale doesn't accurately follow the Standard that is used to produce virtually all consumer content then the Image Colors, Image Contrast, and their Brightness Intensities will be wrong everywhere in all images. Unfortunately, many manufacturers are quite sloppy with the Intensity Scale on their displays (because it is logarithmic rather than linear).

 

Fortunately, the Intensity Scale for the Natural mode on OnePlus 8T is a close to perfect match of the Intensity Scale Standard, and is Visually Indistinguishable from Perfect. See Figure 3 for a plot of the measured Intensity Scale and the Contrast and Intensity Scale section for the measurements and details.

 

· Peak Brightness that is Independent of the on-screen Image Content

The Average Picture Level (APL) for on-screen image content is the Average Brightness (Luminance) over the entire screen, which varies from 0% for an all Black screen, up to 100% for an all White screen at Peak Brightness.

 

On most existing OLED displays the Peak Brightness (Luminance) changes with the APL of the on-screen image, with the Peak Brightness increasing by as much as 50 percent or more between High APL and Low APL. This increasing High Brightness with Low APL effect can be very useful in improving screen readability in High Ambient Light, and also to highlight certain on-screen image content. But the resulting variations in display Brightness can distort the brightness relationships when viewing photos, in videos, and other images, so for display modes that provide High Accuracy the Luminance variation with APL should be as small as possible.

 

On the OnePlus 8T the Luminance variation with picture content APL is a Very Low 2 percent for the Natural mode. But as we discuss next, the main reason for doing this is actually to improve the Absolute Color Accuracy and Absolute Contrast Accuracy of the display. See the Screen Brightness section for the measurements and details.

 

· Color Accuracy and Intensity Scales that are Independent of the on-screen Image Content

The Absolute Color Accuracy and Intensity Scale of the display should not change as the on-screen image content changes.

As we discussed above, the first step is to make sure that the Peak Brightness (Luminance) of the display does not change with the Average Picture Level APL of the on-screen images because High Color Accuracy is impossible when that occurs.

 

With the continuing improvements in display performance we have added a new set of advanced tests that measure the variations in the Absolute Color Accuracy and the Intensity Scales with changing Average Picture Level APL, comparing the Shifts between Low APL and 50% High APL. Previous generation displays with large Peak Luminance changes with APL typically show Large Shifts in the Intensity Scale and Large Shifts in Absolute Color Accuracy with APL. Since the OnePlus 8T has a small 2 percent change in Luminance with APL, we expect Small Shifts in Accuracy with APL, which we analyze next...

 

The Variation in the Intensity Scales between Low APL and 50% APL for the Natural modes is shown Figure 3. Any change in the Intensity Scale will affect the Absolute Color Accuracy. There is only a very small Shift in the Intensity Scales with APL, with the Gamma essentially unchanged with 2.17 for Low APL and 2.17 for 50% APL. As a result, we expect the Absolute Color Accuracy to have very small variations with APL.

 

The Variation in the Absolute Color Accuracy between Low APL and 50% APL for the Natural sRGB and DCI-P3 Modes is shown in Figure 4. The Color Shifts with APL are very small, with an Average Color Shift of just 0.3 - 0.4 JNCD and the Largest Color Shift of only 0.6 JNCD for the Natural Modes. In addition, the White Point Shifts with APL are also very small at 0.5 JNCD.

 

All the Color Shifts and Contrast Shifts with APL are very small and Visually Indistinguishable from Perfect. See this Figure for an explanation and visual definition of JNCD and the Color APL Shifts section for the measurements and details.

 

 

	Color Gamuts Click to Enlarge		Color Accuracy Click to Enlarge		Color Shifts Click to Enlarge		Intensity Scales Click to Enlarge

 

· Natural Mode with Very High Absolute Color Accuracy

Delivering great color with high Absolute Color Accuracy is incredibly difficult because everything on the display has to be done just right. In order to deliver accurate image colors, a display needs to closely match the standard Color Gamut that was used for producing the content being viewed – not more and not less. In addition the display also needs an accurate (pure logarithmic power-law) Intensity Scale, and particularly important is a very accurate White Point.

 

The Natural mode has ICC Color Management that automatically switches to the appropriate Color Gamut Standard for the current on-screen content.

 

The Absolute Color Accuracy of the Natural mode is Truly Impressive as shown in these Figures. It has an Absolute Color Accuracy of 0.6 JNCD (Just Noticeable Color Difference) for the sRGB / Red.709 Color Gamut that is used for most current consumer content, and 0.5 JNCD for the Wider DCI-P3 Color Gamut that is used for 4K UHD TVs and Digital Cinema, which are both Visually Indistinguishable From Perfect, and very likely considerably better than any mobile display, monitor, TV or UHD TV that you have.

 

Note that in order to obtain this High Absolute Color Accuracy the Screen Calibration mode must be set to Natural in Display Settings, and the Vision Comfort Night Mode must also be Off because it changes the White Point of the display from the 6,500 K Standard, which then changes the Absolute Color Accuracy throughout the Color Gamut. See this Figure for an explanation and visual definition of Just Noticeable Color Difference JNCD and the Color Accuracy Plots with 41 Reference Colors showing the measured display Color Errors. See the Color Accuracy section and the Color Accuracy Plots for the measurements and details. Select the Natural mode using Display Settings – it is Not the default Screen Calibration mode for the OnePlus 8T.

 

· Vivid Mode with Vibrant Colors and Contrast

The Vivid mode provides more Vibrant Colors and Higher Image Contrast than the Natural mode by using the wider DCI-P3 Color Gamut together with a steeper Intensity Scale that increases the Color Saturation for all image and picture content. Some people like the more Saturated and Vibrant Colors, plus it is useful for special applications, and especially when using the OnePlus 8T 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. We examine the change in the Color Gamut with Ambient Light below. Select the Vivid mode using Display Settings – it is the factory default Screen Calibration mode for the OnePlus 8T.

 

· Advanced AMOLED Wide Gamut Mode

The Advanced AMOLED Wide Gamut mode has the Wide Native OLED Color Gamut. It provides significantly higher Color Saturation, with a large 142 percent of the Standard sRGB / Rec.709 Color Gamut and 113 percent of the Standard DCI-P3 Color Gamut, very close to the highest that we have ever measured for Smartphones and Tablets.

 

Some people like the more saturated and Vibrant Colors, plus it is useful for special applications, and especially when using the OnePlus 8T 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. We examine the change in the Color Gamut with Ambient Light below. Select the Advanced AMOLED Wide Gamut mode using Display Settings – it is Not the factory default Screen Calibration mode for the OnePlus 8T.

 

· Advanced Screen Calibration Modes with User Adjustable White Points

For the Advanced Screen Modes, the OnePlus 8T has an adjustable White Point Slider that allows users to change color of White. The Slider control allows the White Point Color Temperature for the Advanced sRGB and P3 modes to range from 5,350 K, which has a somewhat Warmer Tint than the Standard D65 White, up to 8,100 K, which has a Bluish (Cold) Tint that some people like. For the Advanced AMOLED Wide mode the White Point ranges from 5,650 K up to 8,950 K. So with the OnePlus 8T you can set the Color of White that you prefer.

 

· Advanced AMOLED Wide Gamut Mode Offsets the Loss of Color Saturation and Color Gamut in Ambient Light

The Advanced AMOLED Wide Gamut mode is particularly useful in moderate to high levels of Ambient Light because its larger Native Color Gamut offsets some of the loss of Color Saturation and Color Gamut that occurs when using the other Accurately Calibrated Standard Screen Calibration modes. This Figure shows the measured decrease in the Natural modes with increasing Ambient Light, from 0 lux, which is perfectly dark, up through 2,000 lux, which corresponds to typical outdoor daylight in shade.

 

At 500 lux, which corresponds to typical office lighting, the measured on-screen Color Gamut for the Natural modes decreases to 90%. At 1,000 lux, which corresponds to very bright indoor lighting or outdoor daylight with an overcast sky, the measured on-screen Color Gamut decreases down to 81%, and at 2,000 lux the measured on-screen Color Gamut falls to 67%. This loss of Color Saturation and wash out in Ambient Light is well known to all display users.

 

The way to improve the Display Color Accuracy and performance in Ambient Light is to start with a larger Color Gamut, like the AMOLED Wide Gamut mode, which is shown in this Figure compared to the Natural modes for 0 lux up through 2,000 lux. At 3,000 lux the AMOLED Wide Gamut mode provides a much better match to the sRGB / Rec.709 Color Gamut than the sRGB Natural mode. The AMOLED Wide Gamut mode also provides a good match to the DCI-P3 Color Gamut at 500 lux. So the AMOLED Wide Gamut mode provides more accurate on-screen colors in moderate to high Ambient Lighting than the Calibrated Natural Modes, which are designed and calibrated for Low Ambient Light. Applying Dynamic Color Management based on the current Ambient Light lux level in the future will able to further improve color accuracy over a wide range of Ambient Light levels, which we discuss further in the Improving Display Performance for Real World Ambient Light section in the Conclusion.

 

· High Screen Brightness and Performance in High Ambient Light

Mobile displays are often used under relatively bright Ambient Light, which washes out the image color saturation 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 OnePlus 8T has both. This is extremely important for screen readability, picture quality, and color accuracy in Ambient Light.

 

With Adaptive Automatic Brightness turned Off and the Brightness slider set Manually to Maximum, the OnePlus 8T produces between 479 to 492 cd/m² (nits) for the Natural mode and 493 to 620 nits for the Vivid mode, based on the Average Picture Level APL of the image content, among the very brightest that we have ever measured for a Smartphone with Automatic Brightness turned Off. See the Screen Brightness section for the measurements and details.

 

The measured OnePlus 8T Screen Reflectance is 4.3 percent, the lowest that we have ever measured for a Smartphone. Our Contrast Rating for High Ambient Light quantitatively measures screen visibility and image contrast under bright Ambient Lighting – the higher the better. As a result of its high Brightness and low Reflectance, the OnePlus 8T has a Contrast Rating for High Ambient Light that ranges from 111 to 114 for the Natural mode and 115 to 144 for the Vivid mode, among the very highest that we have ever measured for a Smartphone. See the Screen Reflectance section for the measurements and details.

 

· High Brightness Mode with Adaptive Automatic Brightness On

On the OnePlus 8T the Maximum Screen Brightness can go much higher when Adaptive 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 Adaptive Automatic Brightness On will provide better high Ambient Light screen visibility and also longer battery running time.

 

When Adaptive Automatic Brightness is turned On, the OnePlus 8T has a High Brightness Mode that produces up to 1,090 cd/m² (nits) in Vivid mode in High Ambient Light, which is where high Brightness is really needed, and is considerably Brighter than with Manual Brightness when Adaptive Automatic Brightness is turned Off.

 

The OnePlus 8T produces up to 790 nits in Vivid mode for an All White Full Screen 100% Average Picture Level APL image, which is the most challenging image for an OLED display because all the pixels are at full power

 

See the Brightness and Contrast, the High Ambient Light and the Screen Reflections sections for the measurements and details.

 

· High Dynamic Range Mobile HDR10+ Display

The OnePlus 8T can play 4K High Dynamic Range content made for 4K UHD TVs. High Dynamic Range (HDR) is the newest performance enhancement feature developed for the latest 4K Ultra HD TVs. The OnePlus 8T is Certified for the new enhanced Mobile HDR10+ that supports Dynamic Metadata and Dynamic Tone Mapping.

 

HDR provides expanded Color, Contrast, and Brightness of video content. In order to provide HDR, the OnePlus 8T has the required Digital Cinema DCI-P3 Wide Color Gamut, plus perfect Blacks and an Infinite Contrast Ratio from its OLED display, and a Peak Brightness that is much greater than the 540 nits that is required for High Dynamic Range. The OnePlus 8T can play the latest streamed mobile HDR videos.

 

· 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 the phone 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 OnePlus 8T display shows a much smaller 22 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.

 

All displays have Color Shifts with Viewing Angle:

The Color Shift of White, which is the most common background color is particularly noticeable on many OLED and LCD displays.

The OnePlus 8T has a small White Shift of just 1.8 JNCD at 30 degrees, which is unlikely to be noticeable.

 

The Color Shifts throughout the entire Color Gamut vary as combinations of the Primary Color Shifts:

The Color Shifts for the Red and Green Primaries are both relatively small, with 2.4 JNCD for Red and 1.6 JNCD for Green at 30 degrees.

 

The Color Shift for the Blue Primary is larger at 3.9 JNCD at 30 degrees, which is just slightly larger than the 3.5 JNCD

needed for a Very Good Green rating, and may be noticeable for some color content but not objectionable.

 

But as explained in our Absolute Color Accuracy Display Technology Shoot-Out article, the color accuracy of

the Blue Region covering the entire range from Cyan to Magenta is generally less critical for visual color accuracy.

While the eye can still detect color differences and color errors in the Blue Region, for the most part we are

less likely to notice or be troubled by color differences and discrepancies with colors in the Blue Region.

So a larger Blue Color Shift is less noticeable than the Red and Green Color Shifts found in many Smartphone displays.

 

Overall, the OnePlus 8T has close to the Best Viewing Angle Performance that we have ever measured.

See the Viewing Angles section for the measurements and details.

 

· Vision Comfort Night Mode with Reduced Blue Light for Better Night Viewing

For the OnePlus 8T the amount of potentially harmful very short wavelength Blue Light has been significantly reduced while still maintaining the same Wide Color Gamut. The OnePlus 8T has received the TUV Rheinland Eye Comfort Certification for Low Blue Light, Reduced Flicker and Reflection. This has been accomplished with a new Blue OLED with an improved light spectrum that has a reduced short wavelength component. The Improved Blue Light Spectrum also works in conjunction with the Vision Comfort Night Mode...

 

The Vision Comfort Night Mode on the OnePlus 8T is designed to change the color balance of the display in order to reduce the amount of Blue Light produced by the display, which some recent research indicates can affect how well users sleep afterwards. In a separate article we explain and analyze the Blue Light issue for displays. The OnePlus 8T includes a user adjustable Color Temperature slider to vary the amount of Blue light produced by the display and a timer that allows the Vision Comfort Night Mode to be turned on and off automatically every day. The measured variation in the display light spectrum with the adjustable Color Temperature slider is shown in this Figure and below.

 

As the Vision Comfort Night Mode Color Temperature slider setting is moved to the Warmest setting, the amount of Blue light emitted by the display decreases. When that happens, White and all screen colors take on an increasing yellowish tint and color cast. At the Middle setting the measured White Color Temperature decreases to 4,860 K, and at the Warmest setting it decreases to 3,790 K, the Color Temperature of traditional incandescent lighting, which is yellowish.

 

With the Vision Comfort Night Mode turned On and at its Warmest slider setting, the Blue Light is reduced by up to 65 percent together with the Vision Comfort Night Mode Lightness slider. The measured display spectra for several of the Vision Comfort Night Mode settings are included in this Figure and below.

 

	Display Spectra Click to Enlarge

 

· Super Dim Setting

The OnePlus 8T also has a Super Dim Setting 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 perfect for night use on a beside table, and 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 provides full 24-bit color and the picture quality remains excellent.

 

·  Dark Mode

A Dark Mode display setting provides a Dark Tone Theme that inverts the typical White Background with Black Text to a Black Background with White Text for many Apps. This significantly reduces the overall Brightness of the entire display for most applications, and should reduce eye strain when viewing the display in low to dark ambient light. An additional bonus is that switching to a Black Background will in most cases significantly reduce the battery power used by the OLED display.

 

· Viewing Tests Performance

The Natural mode on the OnePlus 8T provides very nice, pleasing and Very Accurate Colors and Picture Quality. The very challenging set of DisplayMate Test and Calibration Photos that we use to evaluate picture quality looked absolutely stunning and Beautiful, even to my experienced hyper-critical eyes.

 

The Absolute Color Accuracy on the OnePlus 8T Natural mode is 0.5 - 0.6 JNCD, which is Visually Indistinguishable From Perfect, and almost certainly considerably better than your existing Smartphone, living room HDTV, Tablet, Laptop, and computer monitor, as demonstrated in our extensive Absolute Color Accuracy Lab Measurements.

 

In order to see the OnePlus 8T High Color Accuracy, the Display Setting needs to be set to the Natural mode, which Automatically Switches to the proper Gamut for the current on-screen content.

 

For indoor and low ambient light viewing use the Natural mode for most standard consumer content including digital camera, TV, internet, and computer content, including photos, videos, and movies, and also for your online purchases in order to see accurate product colors, and also for viewing the newest DCI 4K Ultra HD TV and Digital Cinema content and videos, including HDR content.

 

The Vivid mode and Advanced AMOLED Wide Gamut mode provide significantly more Vibrant and Saturated Colors, which some people prefer. They are recommended for viewing in medium to high levels of ambient light because it offsets some of the reflected light glare that washes out the image colors, which is demonstrated in this Figure for ambient light levels up through 2,000 lux.

 

· Display Power Efficiency

Since 2013 the Display Power Efficiency of OLED Smartphone Displays has improved by a very impressive 65%.

 

While LCDs remain more power efficient for images with mostly full screen white content (like all text screens on a white background, for example), OLEDs are more power efficient for typical mixed image content because they are emissive displays so their power varies with the Average Picture Level (average Brightness) of the image content over the entire screen.

 

For LCDs the display power is fixed and independent of the image content. But for OLEDs, the display power decreases with the type of image content. Black pixels and sub-pixels don’t use any power so screens with Black or dark backgrounds are very power efficient for OLEDs. Photos and videos also have relatively low Average Picture Levels and so require much less power on OLEDs than LCDs. Currently, OLED displays are more power efficient than LCDs for Average Pictures Levels of 70 percent or less, and LCDs are more power efficient for Average Picture Levels above 70 percent. Since both technologies are continuing to improve their power efficiencies, the crossover will continue to change with time. See the Display Power section for the measurements and details.

 

 

 

 

 

 

OnePlus 8T Conclusions:   A Record Setting 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, reviewers, and even manufacturers are aware of and appreciate the very best in displays and display technology. We point out which manufacturers 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 of the DisplayMate Display Performance Grades, Ratings and Awards are based Entirely on the extensive objective Lab Tests and Measurements that we also publish, so that everyone can judge and compare the display performance data for themselves as well.

 

Comparison of the OnePlus 8T with the OnePlus 8 and OnePlus 8 Pro

The OnePlus 8T is an enhanced version of the OnePlus 8 that includes some display functions and features found on the OnePlus 8 Pro.

 

· Improved 120 Hz Display Refresh Rate compared to the 90 Hz Refresh Rate on the OnePlus 8.

 

· Improved Display Calibration Color Accuracy and Image Contrast Accuracy.

 

· Improved High Brightness Mode Luminance Accuracy.

 

You can compare their display performance in detail by using a Tabbed web browser with our DisplayMate Display Technology Shoot-Out articles for each model.

 

Summary of the OnePlus 8T Display Functions, Features, Performance Records and Awards:

The OnePlus 8T has many state-of-the-art Display Functions, Features, Performance Records and Awards that are summarized below:

 

See the Display Performance Functions and Features section below for a list of the main functions and features.

 

See the Display Highlights and Performance Results section above for detailed information, explanations, and analysis.

 

See the Display Performance Records section below that lists the Lab measurement performance records.

 

See the Display Performance Assessments section below summarizes the display evaluation details.

 

See the Best Smartphone Display Award section below summarizes the DisplayMate Display Performance Award and Criteria.

 

See the Display Shoot-Out Lab Measurements Comparison Table section below for the complete set of measurements and tests.

 

The OnePlus 8T has the following State-of-the-Art Display Performance Functions and Features:

 

· A State-of-the-Art Full Screen Flexible OLED display panel from Samsung Display that is manufactured on a flexible plastic substrate. While the OLED display itself is flexible, the screen remains rigid under an outer hard cover glass.

 

· A Full Screen design with a large 6.55 inch OLED display that fills almost the entire front face of the OnePlus 8T from edge-to-edge, with a high 92% Screen-to-Body Ratio, providing a significantly larger display for the same overall phone size.

 

· The display has a very small circular Punch-hole at the very top of the screen for the front facing selfie camera and sensors. The Camera Punch-hole is just 3.9mm in diameter, taking up only a tiny 0.1% of the total display area, a key factor in its high 92% Screen-to-Body Ratio.

 

· A display form factor with a taller height to width Aspect Ratio of 20 : 9 = 2.22, which is 25% larger than the 16 : 9 = 1.78 on most Smartphones (and widescreen TVs) because the display now has the same overall shape as the entire phone. It is taller in Portrait mode and wider in Landscape mode. This provides extra space for Notifications and for displaying multiple Apps and content simultaneously on-screen side-by-side.

 

· A New Higher 120 Hz Display Refresh Rate that improves image Scrolling and Videos, plus Motion and Gaming Performance in Apps, and may also reduce Screen Flicker that some people experience.

 

· A 2K+ High Resolution 2400 x 1080 Full HD+ Display with 402 pixels per inch, and Diamond Pixels with Sub-Pixel Rendering for enhanced sharpness and higher Peak Brightness.

 

· The OnePlus 8T display appears Perfectly Sharp for normal 20/20 Vision at Typical Smartphone Viewing Distances of 12 to 18 inches (25 to 46 cm).

 

· Very Low Screen Reflectance of 4.3 percent.

 

· Image Brightness that is Independent of the on-screen Image Content with only a 2 percent Luminance Shift with Average Picture Level APL.

 

· A High Brightness Mode with a 100% APL Full Screen Peak Display Brightness of 790 nits, and a Peak Display Brightness of 1,090 nits, which significantly improves screen visibility in very high Ambient Light, and also provides the high screen Brightness needed for HDR.

 

· Each OnePlus 8T display is individually calibrated at the factory for both Color Accuracy and Contrast Accuracy.

.

· Very High Absolute Color Accuracy (0.5 - 0.6 JNCD) that is Visually Indistinguishable From Perfect.

 

· Very High Image and Picture Contrast Accuracy and Intensity Scale Accuracy (2.17 Gamma) that is Visually Indistinguishable From Perfect.

 

· Color Accuracy and Intensity Scales that are Independent of the Image Content.

 

· Automatic Color Management that automatically switches to the proper Color Gamut for any displayed image content that has an ICC Profile within the OLED Wide Color Space, so images automatically appear with the correct colors, neither over-saturated or under-saturated.

 

· 2 Industry Standard Calibrated Color Gamuts: the sRGB / Rec.709 Color Gamut that is used for most current consumer content, and the new Wide DCI-P3 Color Gamut that is used in 4K Ultra HD TVs. The DCI-P3 Gamut is 26 percent larger than the sRGB / Rec.709 Gamut.

 

· 3 Selectable Screen Calibration modes that provide user control of the color from the Accurate Natural mode to the Vivid and AMOLED Wide Gamut modes.

 

· A full 100% DCI-P3 Color Gamut with the Natural mode that is also used for 4K Ultra HD TVs, so the OnePlus 8T can display the latest high-end 4K video content. The DCI-P3 Gamut is 26 percent larger than the Rec.709 Gamut that is used in 2K Full HD TVs.

 

· A large Native Color Gamut with a very impressive 113% of DCI-P3 and 142% of sRGB / Rec.709 Gamuts that also provides much better on-screen Colors in High Ambient Light.

 

· The OnePlus 8T has received the TUV Rheinland Eye Comfort Certification for Low Blue Light, Reduced Flicker and Reflection.

 

· A Vision Comfort Night Mode that allows the user to adjust and reduce the amount of Blue Light from the display for better night viewing and improved sleep.

 

· A Dark Mode setting that inverts the typical White Background with Black Text to a Black Background with White Text, which significantly reduces the overall Brightness of the entire display for most applications, and should reduce eye strain when viewing the display in low to dark ambient light.

 

· A High Dynamic Range Mobile HDR10+ Display that allows the OnePlus 8T to play 4K High Dynamic Range content produced for 4K UHD TVs. The OnePlus 8T has the new enhanced Mobile HDR10+ that supports Dynamic Metadata and Tone Mapping.

 

· A User Adjustable White Point with a slider control that can change the color of White for the Advanced Screen Calibration modes.

 

· Small Brightness Shifts and Color Shifts with Viewing Angle, particularly White, which is the most used background color.

 

· Vision Accessibility Display Modes to help people with vision impairments.

 

· The OnePlus 8T can be used with Polarized Sunglasses in both the Portrait and Landscape orientations unlike LCDs, which generally work in only one of the two orientations.

 

The OnePlus 8T sets or matches 11 Smartphone Display Performance Records for:

Measured Numerical Display Performance Differences that are Visually Indistinguishable are considered Matched and Tied Performance Records.

 

· Smallest  Shift in Color Accuracy and Intensity Scale with the Image Content APL  (0.3 JNCD)  –  Visually Indistinguishable From Perfect.

 

· Highest   Absolute Color Accuracy  (0.5 JNCD)  –  Visually Indistinguishable From Perfect.

 

· Highest   Image Contrast Accuracy and Intensity Scale Accuracy  (2.17 Gamma)  –  Visually Indistinguishable From Perfect.

 

· Smallest  Shift in Image Contrast and Intensity Scale with the Image Content APL  (0.01 Gamma)  –  Visually Indistinguishable From Perfect.

 

· Smallest  Change in Peak Luminance with the Image Content Average Picture Level APL  (2 percent)  –  Visually Indistinguishable From Perfect.

 

· Highest   Full Screen Brightness for OLED Smartphones  (790 nits at 100% Average Picture Level).

 

· Largest   Native Color Gamut  (113% DCI-P3 and 142% sRGB / Rec.709 for the AMOLED Wide Mode).

 

· Highest   Contrast Ratio  (Infinite).

 

· Lowest    Screen Reflectance  (4.3 percent).

 

· Highest   Contrast Rating in Ambient Light  (184 for 100% Average Picture Level).

 

· Smallest  Brightness Variation with Viewing Angle  (22 percent at 30 degrees).

 

The OnePlus 8T earns our Highest A+ Display Rating

OLED has evolved into a highly refined and mature display technology that now produces the best and highest performance displays for Smartphones.

OLED Display Performance continues to provide major Record Setting improvements with every new generation.

 

With consumers now spending rapidly increasing amounts of time watching content on their Smartphones, the shift in emphasis from primarily improving Display Hardware Performance to enhancing the overall display Picture Quality and Color Accuracy is an important step that DisplayMate Technologies has been pushing for many years in our Display Technology Shoot-Out article series, so it is great to see manufacturers improving and then competing on these DisplayMate Objective Lab Measurement Metrics.

 

OnePlus has concentrated on significantly raising the on-screen Absolute Picture Quality and Absolute Color Accuracy of the OLED display by implementing Precision Factory Display Calibration, moving the overall OnePlus 8T Display Performance up to Record Setting Outstanding Levels with close to Text Book Perfect Calibration Accuracy that is Visually Indistinguishable From Perfect.

 

DisplayMate Display Performance Ratings:

All of the Results in this article are based Entirely on our Objective and Extensive DisplayMate Lab Tests and Measurements that are all listed in a section below.

 

To get a DisplayMate A Display Performance Rating the display must get All Green [Very Good to Excellent] Ratings for All of the Display Tests and Measurements [except for Color Shifts at 30 degrees Viewing Angle, which are deemed less important].

 

And to get a DisplayMate A+ Display Performance Rating the Average Absolute Color Accuracy and the Average Absolute Color Accuracy Shifts with Average Picture Level APL must All be less than 1.0 JNCD, and the Largest Color Errors must All be less than 3.0 JNCD.

 

The OnePlus 8T delivers Uniformly Consistent Top Tier Display Performance and receives All Green [Very Good to Excellent] Ratings in All DisplayMate Lab Test Display Performance and Accuracy Categories and has Absolute Color Accuracy much better than 1.0 JNCD.

 

As a Result the OnePlus 8T display meets all of the criteria and requirements for a DisplayMate A+ Grade, earning DisplayMate’s Highest Overall Display Assessment Rating and Highest Display Performance Grade of A+.

 

DisplayMate Display Performance Rating and Best Smartphone Display Award

 

Based on our extensive Lab Tests and Measurements the OnePlus 8T has a Very Impressive Excellent Top Tier World Class Smartphone Display with close to Text Book Perfect Calibration Accuracy and Performance that is Visually Indistinguishable From Perfect. Based on our objective Lab Tests and Measurements the OnePlus 8T receives a DisplayMate Best Smartphone Display Award earning DisplayMate’s highest ever Display Performance Grade of A+ and setting or matching 11 Smartphone Display Performance Records that are listed above.

 

OnePlus 8T Joins the Top Tier of Smartphone Displays

The OnePlus 8T joins the very select Top Tier of Smartphone Displays which all provide Close to Text Book Perfect Calibration Accuracy and Performance that is Visually Indistinguishable From Perfect, so they all received and maintain Concurrent DisplayMate Best Smartphone Display Awards. All are Excellent State-of-the-Art Displays, each is better in some Display Performance Categories, but None are Best in All the Display Performance Categories. Note that measured numerical display performance differences that are Visually Indistinguishable are equivalent.

 

As Display Performance continues to improve we have and will continue to raise the Performance Levels necessary to receive a DisplayMate Best Smartphone Display Award and an A+ Display Rating, so the Top Tier of Smartphone Displays will continue to evolve and change with each new display generation, but only the Very Best Displays will continue to receive A+ Ratings each year.

 

OLED displays now have tremendous performance advantages over LCDs, so high-end and flagship Smartphones need OLED displays in order to compete at state-of-the-art performance levels, securing OLED as the definitive premier display technology for Top Tier Smartphones in the foreseeable future over the next 3-5 years. With the continuing improvements in OLED hardware performance, picture quality, and precision accuracy, it will be much harder for new display technologies to challenge OLED.

 

Follow DisplayMate on Twitter to learn about our upcoming Smartphone display technology coverage.

 

See the links below for all of the OnePlus 8T Measurements, Evaluations, Analysis, and Assessments

 

Data Tables:    See the Display Shoot-Out Lab Measurements Comparison Table section below has the complete set of measurements and tests.

 

Highlights:       See the Display Highlights and Performance Results section above for detailed information, explanations, and analysis.

 

Features:         See the Display Performance Functions and Features section above for a list of the main functions and features.

 

Records:          See the Display Performance Records section above that lists the Lab measurement performance records.

 

Assessments:   See the Display Performance Assessments section below summarizes the display evaluation details.

 

The Future of OLED Smartphones

OLED has evolved into a highly refined and mature display technology that now produces the best and highest performance displays for Smartphones.

The OnePlus 8T is the latest in a new generation of OLED Smartphones. OLEDs have now evolved and emerged as the premium mobile Smartphone display technology.

 

LCDs are a great cutting edge high performance display technology for Tablets to TVs, but for small handheld Smartphones, OLED displays provide a number of major advantages over LCDs including: being much thinner, much lighter, without needing a bezel, providing a rimless edge-to-edge design. They can be made flexible and into curved screens, plus they have a very fast response time, better viewing angles, and always-on display modes.

 

Many of the OLED performance advantages result from the fact that every single sub-pixel in an OLED display is independently directly electrically powered to emit light, so only the active image sub-pixels draw power based on their individual brightness levels. OLEDs can also provide better color accuracy, image contrast accuracy, and screen uniformity because the irregularities and variations in LCD Backlights introduce color and brightness irregularities and variations over the screen.

 

As the result of their very versatile power management capabilities, OLEDs are not only more power efficient than LCDs for most image content, but they now deliver much higher peak Brightness than LCDs because the maximum power can be delivered to just the sub-pixels that are needed for producing the current displayed image. However, for mostly all white screen content, LCDs are likely to remain brighter and more power efficient for a while.

 

OLED displays are also manufactured on flexible substrates that can bend, which allows the screens to be curved and rounded and provides a number of innovative new screen geometries.

 

As a result, OLED displays now have tremendous performance advantages over LCDs, so high-end and flagship Smartphones need OLED displays in order to compete at state-of-the-art performance levels, securing OLED as the definitive premier display technology for Top Tier Smartphones in the foreseeable future over the next 3-5 years. With the continuing improvements in OLED hardware performance, picture quality, and precision accuracy, it will be much harder for new display technologies to challenge OLED.

 

Follow DisplayMate on Twitter to learn about these developments and our upcoming display technology coverage.

 

Improving the Next Generation of Mobile Displays

The OnePlus 8T has a high resolution 2K+ 2400x1080 pixel display with Diamond Pixels at 402 pixels per inch (ppi) producing images that look perfectly sharp with normal 20/20 Vision under all normal viewing conditions, which always includes some ambient light that always lowers the visible image contrast and perceived image sharpness (Modulation Transfer MTF). Note that displays are almost never viewed in absolute darkness under perfect viewing conditions with ideal image content. Some clueless reviewers have been pining for 4K 3840x2160 Smartphones, which would require 3 times the pixels, memory, and processing power of the 2400x1080 display on the OnePlus 8T, but there would be no visual benefit for humans! As a result, it is absolutely pointless to further increase the display resolution and pixels per inch (ppi) for a marketing wild goose chase into the stratosphere, with no visual benefit for humans!

 

Improving Display Performance for Real World Ambient Light Viewing Conditions

With screen size and resolution already functionally maxed out, manufacturers should instead dedicate their efforts and resources into improving real world display performance in ambient light by using advanced technology to restore and compensate for the loss of color gamut, color saturation, and image contrast due to ambient light, something that every consumer will benefit from, and will also immediately notice and appreciate – providing a true sales and marketing advantage.

 

Currently all existing displays are Color and Contrast Accurate only when they are viewed in Absolute Darkness 0 lux.

The most important improvements for OLED and LCD displays will come from improving their image and picture quality and screen readability in Real World Ambient Light, which washes out the screen images, resulting in Reduced Image Contrast, Reduced Color Saturation, and Reduce Color Accuracy. The key will be in lowering the Screen Reflectance and implementing Dynamic Color Management with automatic real-time modification of the display’s native Color Gamut and Dynamic Intensity Scales based on the measured Ambient Light level in order to have them compensate for the reflected light glare and image wash out that causes a loss of color saturation and image contrast from ambient light as discussed in our Innovative Displays and Display Technology and SID Display Technology Shoot-Out articles.

 

Currently all existing displays deal with increasing Ambient Light by simply increasing the display’s own Brightness - a brute force method that does very little to improve the washed out Colors and Image Contrast, but it significantly increases Display Power, which then reduces the Running Time on Battery. A major bonus for using Dynamic Color Management and Dynamic Intensity Scales is that it significantly reduces Display Power, which then increases the Running Time on Battery, another major sales and marketing advantage for this new high tech approach.

 

The displays, technologies, and manufacturers that succeed in implementing this new real world high ambient light 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.

 

DisplayMate Display Optimization Technology

All Smartphone, Tablet, Monitor and TV 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, display performance improvement and optimization, 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.

 

 

Display Shoot-Out Lab Measurements Comparison Table

Below we examine in-depth the OLED display performance of the OnePlus 8T based on objective Lab measurement data

and criteria in the following sections:  Display Specifications,  Overall Assessments,  Screen Reflections,  Brightness and Contrast,

Colors and Intensities,  Absolute Color Accuracy,  Viewing Angles,  OLED Spectra,  Display Power.

 

For comparisons with the other leading Smartphone displays see our Mobile Display Technology Shoot-Out series.

 

Categories	OnePlus 8T			Comments
Display Technology	Flexible OLED Display with Diamond Pixels 6.55 inch Diagonal  /  16.6 cm Diagonal Excluding the Rounded Corners			Flexible Organic Light Emitting Diode Diamond Pixels with Diagonal Sub-Pixel Symmetry.
Screen Aspect Ratio	20: 9 = 2.22 New Higher Aspect Ratio Most Smartphones and Widescreen TVs have 16 : 9 = 1.78			Height to Width Aspect Ratio OnePlus 8T display screen is 25% longer than most Smartphones and widescreen 16:9 TV content.
Screen Size	2.69 x   5.97 inches 6.82 x 15.16 cm			Display Width and Height in inches and cm.
Screen Area	16.0 square inches  /  103.4 square cm After Subtracting the Camera Opening but not the Rounded Corners			A better measure of size than the Diagonal.
Screen–to–Body Ratio	92%			Area of the Screen compared to the Phone.
Supported Color Gamuts	Vivid mode  –  Wide Color Gamut with Higher Contrast Natural DCI-P3 mode  –  DCI-P3 Standard Color Gamut                Natural sRGB mode  –  sRGB / Rec.709 Standard Color Gamut Advanced AMOLED Wide mode  –  Native OLED Color Gamut with Higher Contrast			The OnePlus 8T supports 2 Standard Color Gamuts: sRGB and the new wider DCI-P3 Color Gamut that is used in 4K Ultra HD TV content.
Display Refresh Rates	Display Refresh Frames Per Second Normal 60 Hz Refresh High 120 Hz Refresh for Smoother Scrolling and Motion			Higher Refresh Rates improve image Scrolling plus Video and Motion Performance in Apps, and may reduce Screen Flicker that some people experience.
Display Resolution	2400 x 1080 pixels 2K+  FHD+			Screen Pixel Resolution.
Total Number of Pixels	2.6 Mega Pixels			Total Number of Display Pixels.
Pixels Per Inch  PPI	402 PPI with Diamond Pixels Very Good			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  284 SPPI  Green  402 SPPI    Blue  284 SPPI			Diamond Pixel displays have only half the number of Red and Blue Sub-Pixels as RGB Stripe displays. At High PPI this is generally not visible due to the use of Sub-Pixel Rendering.
Total Number of Sub-Pixels	Red  1.3 Million Sub-Pixels Green  2.6 Million Sub-Pixels   Blue  1.3 Million Sub-Pixels			Diamond Pixel displays have only half the number of Red and Blue Sub-Pixels as RGB Stripe 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	8.6 inches / 21.7 cm  for White and Green Sub-Pixels with 20/20 Vision  12.1 inches / 30.7 cm  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 12 inches from the screen 20/20 Vision is 344 PPI.
Display Sharpness at Typical Viewing Distances	OnePlus 8T Display appears Perfectly Sharp Pixels are not Resolved with 20/20 Vision at Typical Viewing Distances of      12 to 18 inches 30 to 46 cm			The Typical Viewing Distances for this screen size are in the range of 12 to 18 inches or 30 to 46 cm.   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 12 to 18 inches or 30 to 46 cm for this screen size.
Overall Display Performance 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,  Absolute Color Accuracy,  Viewing Angles,  OLED Spectra   Here we provide results for the Vivid mode, which has a Wide Color Gamut and Higher Image Contrast, the Natural DCI-P3 mode, which is calibrated for the new DCI-P3 Gamut that is used in 4K Ultra HD TVs, and the Natural sRGB mode, which is calibrated for the sRGB / Rec.709 Gamut that is used for most current consumer photo, video, web, and computer content.
Categories	Vivid mode Wide Color Gamut	Natural mode DCI-P3 Content	Natural mode sRGB Content	Comments
Viewing Tests in Subdued Ambient Lighting	Very Good Images Photos and Videos have Vivid Color and Higher Contrast   Intentionally Vivid Colors	Excellent Images Photos and Videos have Excellent Color and Accurate Contrast   Accurate DCI-P3 Content	Excellent Images Photos and Videos have Excellent Color and Accurate Contrast   Accurate sRGB Content	The Viewing Tests examine the accuracy of photographic images by comparing the displays to a calibrated studio monitor and TV.
Variation with Viewing Angle Colors and Brightness   See Viewing Angles	Color Shifts Small to Medium with Viewing Angle   Small Brightness Shifts with Viewing Angle	Color Shifts Small to Medium with Viewing Angle   Small Brightness Shifts with Viewing Angle	Color Shifts Small to Medium with Viewing Angle   Small Brightness Shifts with Viewing Angle	The OnePlus 8T 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 Vivid Color Mode	Excellent OLED Display Accurate DCI-P3 Content	Excellent OLED Display Accurate sRGB Content	The OnePlus 8T 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 Intentionally Vivid Colors	Excellent Color Accuracy Color Errors are Very Small Accurate DCI-P3 Content	Excellent Color Accuracy Color Errors are Very Small Accurate sRGB Content	Absolute Color Accuracy is measured with a Spectroradiometer for 41 Reference Colors uniformly distributed within the entire Color Gamut.   See Figure 2 and Colors for details.
Image Contrast Accuracy   See Figure 3 and Contrast	Very Good Accuracy Image Contrast Intentionally Higher	Excellent Accuracy Image Contrast Very Accurate	Excellent Accuracy Image Contrast Very Accurate	The Image Contrast Accuracy is determined by measuring the Log Intensity Scale and Gamma.   See Figure 3 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 for Ambient Light   Higher Brightness with Auto Brightness On	High Display Brightness Very Low Reflectance   High Contrast Rating for Ambient Light   Higher Brightness with Auto Brightness On	High Display Brightness Very Low Reflectance   High Contrast Rating for Ambient Light   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	Wide Color Gamut Mode Intentionally Vivid Colors and Higher Image Contrast	Excellent Calibration Accurate DCI-P3 Content	Excellent Calibration Accurate sRGB Content	OnePlus 8T display has Natural and Natural Modes that deliver accurately calibrated colors and images and a Vivid Color Mode that is preferred by some users and for some applications.
Overall Display Grade Overall Assessment	Overall OnePlus 8T Display Grade is Excellent A+ DisplayMate Best Smartphone Display Award with 11 Smartphone Display Performance Records An Excellent Top Tier World Class Smartphone Display			The OnePlus 8T display delivers Excellent Image Quality, has both Natural sRGB and Natural DCI-P3 modes and a Vivid Mode with a Wide Color Gamut, has High Screen Brightness and low Reflectance, has good Viewing Angles, and is an all around Top Performing Smartphone Display.
	Vivid Color Mode Also Best for Viewing in High Ambient Light	Accurate DCI-P3 Content For Viewing 4K UHD TV DCI-P3 Cinema Content	Accurate sRGB mode For Viewing Most Content Photo Video Movie Web
Categories	Vivid mode Wide Color Gamut	Natural mode DCI-P3 Content	Natural mode sRGB Content	Comments
The OnePlus 8T sets or matches 11 Smartphone Display Performance Records for: Measured Numerical Display Performance Differences that are Visually Indistinguishable are considered Matched and Tied Performance Records.   · Smallest  Shift in Color Accuracy and Intensity Scale with the Image Content APL  (0.3 JNCD)  –  Visually Indistinguishable From Perfect.   · Highest   Absolute Color Accuracy  (0.5 JNCD)  –  Visually Indistinguishable From Perfect.   · Highest   Image Contrast Accuracy and Intensity Scale Accuracy  (2.17 Gamma)  –  Visually Indistinguishable From Perfect.   · Smallest  Shift in Image Contrast and Intensity Scale with the Image Content APL  (0.01 Gamma)  –  Visually Indistinguishable From Perfect.   · Smallest  Change in Peak Luminance with the Image Content Average Picture Level APL  (2 percent)  –  Visually Indistinguishable From Perfect.   · Highest   Full Screen Brightness for OLED Smartphones  (790 nits at 100% Average Picture Level).   · Largest   Native Color Gamut  (113% DCI-P3 and 142% sRGB / Rec.709 for the AMOLED Wide Mode).   · Highest   Contrast Ratio  (Infinite).   · Lowest    Screen Reflectance  (4.3 percent).   · Highest   Contrast Rating in Ambient Light  (184 for 100% Average Picture Level).   · Smallest  Brightness Variation with Viewing Angle  (22 percent at 30 degrees).
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. Manufacturers should 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. We use an Integrating Hemisphere and a highly collimated pencil light beam together with a Spectroradiometer. Note that the Screen Reflectance is exactly the same for all of the OnePlus 8T Screen Modes.   The OnePlus 8T has the lowest Screen Reflectance level that we have ever measured for a Smartphone. These results are extremely important for screen readability, picture quality, and color accuracy in ambient light.
Categories	OnePlus 8T			Comments
Average Screen Reflection Light From All Directions	4.3 percent for Ambient Light Reflections Excellent			Measured using an Integrating Hemisphere and a Spectroradiometer. The lowest value we have ever measured for a Smartphone is 4.3 percent.
Mirror Reflections Percentage of Light Reflected	5.3 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. The lowest value we have ever measured for a Smartphone is 5.3 percent.
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 for High Ambient Light, 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 display’s actual on-screen Contrast Ratio changes with the Ambient Light lux level and is proportional to the Contrast Rating.
Categories	Vivid mode Wide Color Gamut	Natural mode DCI-P3 Content	Natural mode sRGB Content	Comments
Home Screen Peak Brightness Measured for White	Brightness 598 cd/m2 Excellent	Brightness 495 cd/m2 Very Good	Brightness 495 cd/m2 Very Good	The Peak Brightness for White on the Home Screen.
Measured Average Brightness 50% Average Picture Level	Brightness 542 cd/m2 Excellent	Brightness 486 cd/m2 Very Good	Brightness 487 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 493 cd/m2 Excellent	Brightness 491 cd/m2 Very Good	Brightness 492 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% Average Picture Level	Brightness 620 cd/m2 Excellent	Brightness 479 cd/m2 Very Good	Brightness 482 cd/m2 Very Good	This is the Peak Brightness for a screen that has only a tiny 1% Average Picture Level.
Dynamic Brightness Change in Luminance with Average Picture Level APL	20 percent Decrease Intentionally Large	2 percent Decrease Excellent	2 percent Decrease Excellent	This is the percent Brightness decrease with APL Average Picture Level. Ideally should be 0 percent.
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 remains 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 Brightness Mode Automatic Brightness in High Ambient Light
Measured High Brightness Mode 50% Average Picture Level	High Brightness Mode 894 cd/m2 Excellent	High Brightness Mode 779 cd/m2 Excellent	High Brightness Mode 777 cd/m2 Excellent	This is the Brightness for typical screen content that has a 50% Average Picture Level.
Measured High Brightness Mode 100% Full screen White	High Brightness Mode 790 cd/m2 Excellent	High Brightness Mode 784 cd/m2 Excellent	High Brightness Mode 783 cd/m2 Excellent	This is the Brightness for a screen that is entirely all white with 100% Average Picture Level.
Measured High Brightness Mode 1% Average Picture Level	High Brightness Mode 1,090 cd/m2 Excellent	High Brightness Mode 767 cd/m2 Excellent	High Brightness Mode 767 cd/m2 Excellent	This is the Peak Brightness for a screen that has only a small 1% Average Picture Level.
Dynamic Brightness Change in Luminance with Average Picture Level APL	28 percent Decrease Intentionally Large	2 percent Decrease Excellent	2 percent Decrease Excellent	This is the percent Brightness decrease with APL Average Picture Level. Ideally should be 0 percent.
High Ambient Light Contrast Rating
Contrast Rating for High Ambient Light   The Higher the Better for Screen Readability in High Ambient Light	115 – 144 With Manual Brightness Very Good   184 – 253 High Brightness Mode Excellent	111 – 114 With Manual Brightness Very Good   178 – 182 High Brightness Mode Excellent	112 – 114 With Manual Brightness Very Good   178 182 High Brightness Mode Excellent	Depends on the Screen Reflectance and Brightness. Defined as Maximum Brightness / Average Reflectance.   The display’s actual on-screen Contrast Ratio changes with the Ambient Light lux level and is proportional to the Contrast Rating.
Screen Readability in High Ambient Light	Very Good  A With Manual Brightness   Excellent  A+ With Auto Brightness On	Very Good  A With Manual Brightness   Excellent  A+ With Auto Brightness On	Very Good  A With Manual Brightness   Excellent  A+ With Auto Brightness On	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 Scales Click to Enlarge   Figure 4 Color Shifts 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.   The OnePlus 8T also has an AMOLED Wide Advanced Mode with the Native Color Gamut of the OLED Display, which is 113% of the DCI-P3 Gamut and 142% of the sRGB Gamut.
Categories	Vivid mode Wide Color Gamut	Natural mode DCI-P3 Content	Natural mode sRGB Content	Comments
Color of White Color Temperature in degrees   Measured in the dark at 0 lux   See Figure 1	7,060 K 2.1 JNCD from D65 White   Intentionally Bluish Mode	6,570 K 0.2 JNCD from D65 White   Very Close to Standard Accurate DCI-P3 Content   See Figure 1	6,570 K 0.2 JNCD from D65 White   Very Close to Standard Accurate sRGB Content   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.   JNCD is a Just Noticeable Color Difference. White Point accuracy is more critical than other colors.   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	100 percent DCI-P3 Cinema Gamut Intentionally Vivid Colors Wide Color Gamut Mode   125percent sRGB / Rec.709 Gamut Intentionally Vivid Colors Wide Color Gamut Mode   See Figure 1	100 percent DCI-P3 Cinema Gamut Very Close to Standard Accurate DCI-P3 Content   See Figure 1	102percent sRGB / Rec.709 Gamut Very Close to Standard Accurate sRGB Content   See Figure 1	Most current consumer content uses sRGB / Rec.709. The new 4K UHD TVs and Digital Cinema use DCI-P3.   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.   See Figure 1
Absolute Color Accuracy
Absolute Color Accuracy Average Color Error at 0 lux   For 41 Reference Colors Just Noticeable Color Difference   See Figure 2	Average Color Error From sRGB / Rec.709 Δ(u’v’) = 0.0189 4.7 JNCD   Intentionally Vivid Colors Wide Color Gamut Mode   See Figure 2	Average Color Error From DCI-P3 Δ(u’v’) = 0.0020 0.5 JNCD   Excellent Accuracy Accurate DCI-P3 Content   See Figure 2	Average Color Error From sRGB / Rec.709 Δ(u’v’) = 0.0024  0.6 JNCD   Excellent Accuracy Accurate sRGB Content   See Figure 2	JNCD is a Just Noticeable Color Difference.   See Figure 2 for the definition of JNCD and for the Accuracy Plots showing the measured Color Errors.   Color Errors below 3.5 JNCD are Very Good. Color Errors 3.5 to 7.0 JNCD are Good. Color Errors above 7.0 JNCD are Poor.
Absolute Color Accuracy Largest Color Error at 0 lux   For 41 Reference Colors Just Noticeable Color Difference   See Figure 2	Largest Color Error From sRGB / Rec.709 Δ(u’v’) = 0.0455 11.4 JNCD for 75% Red   Intentionally Vivid Colors Wide Color Gamut Mode   See Figure 2	Largest Color Error From DCI-P3 Δ(u’v’) = 0.0038 0.9 JNCD for 75% Red   Excellent Accuracy Accurate DCI-P3 Content   See Figure 2	Largest Color Error From sRGB / Rec.709 Δ(u’v’) = 0.0047 1.2 JNCD for 75% Red   Excellent Accuracy Accurate sRGB Content   See Figure 2	JNCD is a Just Noticeable Color Difference.   See Figure 2 for the definition of JNCD and for the Accuracy Plots showing the measured Color Errors.   Color Errors below 3.5 JNCD are Very Good. Color Errors 3.5 to 7.0 JNCD are Good. Color Errors above 7.0 JNCD are Poor.
Changes in Absolute Color Accuracy with Average Picture Level APL Measured Shifts in the Absolute Color Accuracy with Image Content from Low 1% APL to High 50% APL
Shift in the Color of White   Just Noticeable Color Difference   See Figure 4	White Point Color Shift from Low to High APL Δ(u’v’) = 0.0016 0.4 JNCD   Excellent	White Point Color Shift from Low to High APL Δ(u’v’) = 0.0016 0.4 JNCD   Excellent   See Figure 4	White Point Color Shift from Low to High APL Δ(u’v’) = 0.0020 0.5 JNCD   Excellent   See Figure 4	JNCD is a Just Noticeable Color Difference   See Figure 2 for the definition of JNCD. See Figure 4 for the measured Color Shifts.   Color Shifts below 3.5 JNCD are Very Good. Color Shifts 3.5 to 7.0 JNCD are Good. Color Shifts above 7.0 JNCD are Poor.
Average Color Shift   For 41 Reference Colors Just Noticeable Color Difference   See Figure 4	Vivid mode   Intentionally Variable	Average Color Shift from Low to High APL Δ(u’v’) = 0.0013 0.3 JNCD   Excellent   See Figure 4	Average Color Shift from Low to High APL Δ(u’v’) = 0.0015 0.4 JNCD   Excellent   See Figure 4	JNCD is a Just Noticeable Color Difference.   See Figure 2 for the definition of JNCD. See Figure 4 for the measured Color Shifts.   Color Shifts below 3.5 JNCD are Very Good. Color Shifts 3.5 to 7.0 JNCD are Good. Color Shifts above 7.0 JNCD are Poor.
Largest Color Shift   For 41 Reference Colors Just Noticeable Color Difference   See Figure 4	Vivid mode   Intentionally Variable	Largest Color Shift from Low to High APL Δ(u’v’) = 0.0024 0.6 JNCD for 75% Cyan-Blue   Excellent   See Figure 4	Largest Color Shift from Low to High APL Δ(u’v’) = 0.0022 0.5 JNCD for 100% Cyan-Blue   Excellent   See Figure 4	JNCD is a Just Noticeable Color Difference   See Figure 2 for the definition of JNCD. See Figure 4 for the measured Color Shifts.   Color Shifts below 3.5 JNCD are Very Good. Color Shifts 3.5 to 7.0 JNCD are Good. Color Shifts above 7.0 JNCD are Poor.
Intensity Scale and Image Contrast Accuracy
Dynamic Brightness Change in Luminance with Average Picture Level APL	20 percent Decrease Intentionally Large	2 percent Decrease Excellent	2 percent Decrease Excellent	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	Very Smooth and Straight Excellent Very Accurate   See Figure 3	Very Smooth and Straight Excellent Very Accurate   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	2.46 Very Good Gamma Intentionally High	2.17 Excellent Gamma Very Accurate	2.17 Excellent Gamma Very Accurate	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	Excellent	Excellent	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.   The Viewing Angle variations are essentially identical for all of the OnePlus 8T Screen Modes.   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 OnePlus 8T display has a Brightness (Luminance) fall off with Viewing Angle that is much smaller than the best LCD displays.   Color Shifts: The White Point Color Shift is the most viewer noticeable Color Shift with Viewing Angle because it is often the screen background. The OnePlus 8T has a very small White Shift of just 1.8 JNCD at 30 degrees, which is unlikely to be noticeable.   The Color Shifts throughout the entire Color Gamut vary as combinations of the Primary Color Shifts. The Color Shifts for the Red and Green Primaries are both relatively small, with 2.4 JNCD for Red and 1.6 JNCD for Green at 30 degrees.   The Color Shift for the Blue Primary is larger at 3.9 JNCD at 30 degrees, which is just slightly larger than the 3.5 JNCD needed for a Very Good Green rating, and may be noticeable for some color content but not objectionable.   But as explained in our Absolute Color Accuracy Display Technology Shoot-Out article, the color accuracy of the Blue Region covering the entire range from Cyan to Magenta is generally less critical for visual color accuracy. While the eye can still detect color differences and color errors in the Blue Region, for the most part we are less likely to notice or be troubled by color differences and discrepancies with colors in the Blue Region. So a larger Blue Color Shift is less noticeable than the Red and Green Color Shifts found in many Smartphone displays.   Overall, the OnePlus 8T has close to the Best Viewing Angle Performance that we have ever measured.
Categories	Vivid mode Wide Color Gamut	Natural mode DCI-P3 Content	Natural mode sRGB Content	Comments
Brightness Decrease at a 30 degree Viewing Angle	22 percent Decrease Small Decrease Very Good			Most screens become less bright when tilted. 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 Color Shift Δ(u’v’) = 0.0071  1.8 JNCD  Excellent			JNCD is a Just Noticeable Color Difference. See Figure 2 for the definition of JNCD. Color Shifts below 3.5 JNCD are Very Good.
Color Shifts for the Primaries
Red Primary Color Shift at a 30 degree Viewing Angle	Small Color Shift Δ(u’v’) = 0.0097  2.4 JNCD  Very Good			JNCD is a Just Noticeable Color Difference. See Figure 2 for the definition of JNCD. Color Shifts below 3.5 JNCD are Very Good.
Green Primary Color Shift at a 30 degree Viewing Angle	Small Color Shift Δ(u’v’) = 0.0064  1.6 JNCD  Excellent			JNCD is a Just Noticeable Color Difference. See Figure 2 for the definition of JNCD. Color Shifts below 3.5 JNCD are Very Good.
Blue Primary Color Shift at a 30 degree Viewing Angle	Medium Color Shift Δ(u’v’) = 0.0157 3.9 JNCD  Good			JNCD is a Just Noticeable Color Difference. See Figure 2 for the definition of JNCD. Color Shifts 3.5 to 7.0 JNCD are Good.
Color Shifts for Color Mixtures at a 30 degree Viewing Angle Reference Brown (255, 128, 0)	Small Color Shift Δ(u’v’) = 0.0041 1.0 JNCD  Excellent			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 Spectra The Display Spectra for the Vivid and Natural Modes and for the Vision Comfort Night Mode are measured in Figure 5 below.   The Vision Comfort Night Mode is designed to change the color balance of the display in order to reduce the amount of Blue Light produced by the display, which some recent research indicates can affect how well users sleep afterwards.       Figure 5 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. All the measurements were performed in the AMOLED Wide Mode set for FHD+ (2400x1080) Resolution and 120 Hz Refresh rate.   Comparison with LCDs While LCDs remain more power efficient for images with mostly full screen white content (like all text screens on a white background, for example), OLEDs are more power efficient for typical mixed image content because they are emissive displays so their power varies with the Average Picture Level (average Brightness) of the image content over the entire screen. For OLEDs, Black pixels and sub-pixels don’t use any power so screens with Black backgrounds are very power efficient for OLEDs. For LCDs the display power is fixed and independent of image content.   For OLEDs the Display Power depends on the Picture Content. An entirely Black OLED Screen uses 0 watts of Display Power.   Currently, OLED displays are more power efficient than LCDs for Average Pictures Levels of 70 percent or less, and LCDs are more power efficient for Average Picture Levels above 70 percent. Since both technologies are continuing to improve their power efficiencies, the crossover will continue to change with time.   Categories OnePlus 8T AMOLED Wide Mode 120 Hz Refresh Rate Comments Average Display Power Maximum Brightness at 50% Average Picture Level 50% Average Picture Level   1.70 watts with 554 cd/m2 16.0 inch2 Screen Area This measures the Average Display Power for a wide range of image content.   Maximum Display Power Full White Screen                       at Maximum Brightness Maximum Power Full Screen White   3.00 watts with 498 cd/m2 16.0 inch2 Screen Area This measures the Maximum 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, Tablet, Monitor and TV 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, display performance improvement and optimization, 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, TVs, 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:  OnePlus 8 Display Technology Shoot-Out

Article Links:  OnePlus 8 Pro Display Technology Shoot-Out

 

Article Links:  Display Color Gamuts Shoot-Out NTSC to Rec.2020

Article Links:  Absolute Color Accuracy Display Technology Shoot-Out

Article Links:  Watching Displays at Night

 

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

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

 

 

Copyright © 1990-2020 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