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Apple Watch Sapphire vs Glass Display Shoot-Out

 

Dr. Raymond M. Soneira

President, DisplayMate Technologies Corporation

 

Copyright © 1990-2015 by DisplayMate Technologies Corporation. All Rights Reserved.

This article, or any part thereof, may not be copied, reproduced, mirrored, distributed or incorporated

into any other work without the prior written permission of DisplayMate Technologies Corporation

 

 

The Apple Watches in Ambient Light

 

Introduction

The world’s best [and most expensive] watches all have a sapphire crystal because sapphire is incredibly hard, making them extremely scratch resistant and almost scratch proof under normal use. But sapphire is fairly expensive, so most watches instead have a glass crystal, which isn’t as hard or scratch resistant as sapphire, but still holds up pretty well.

 

But is there a visual difference between a watch that uses sapphire versus glass? If you were to hold up two identical watches side-by-side, the one with a glass crystal would be about 20 percent brighter than the one with sapphire (due to fundamental principles of optics that reduce its light transmission), so it appears somewhat darker and duller, particularly because the light has to pass through the crystal twice. There are some new upcoming advanced technologies that can make significant improvements on this issue that we’ll mention below.

 

The above discussion is for traditional watches, which work by reflecting ambient light off the watch face that lies below the crystal. On the other hand, the visual consequences from using sapphire and glass are considerably greater when they are used on displays, including smartphones and smart watches, because minimizing screen reflections is especially important for displays, and sapphire has almost double (191%) the Reflectance of glass, which we consider next…

 

Sapphire and Glass for Displays

Virtually all displays work by emitting image light rather than by reflecting ambient light like traditional watches. As a result, any ambient light that is reflected by the cover (glass or sapphire or anything else) washes out the display’s own image light, degrading picture quality, reducing its contrast and color saturation, and making it harder to see the intended image. If you are watching a display in total darkness then the screen Reflectance doesn’t matter, but it has a surprisingly large effect on every display, even in subdued indoor ambient lighting, and it makes an enormous difference outdoors.

 

We’ll show below how large and how important the Reflectance effect is by comparing the display on an Apple Watch that has a Sapphire Crystal to an identical display on an Apple Watch Sport that has Ion-X Glass. The Apple Watch models are perfect for this comparison because they are identical except for their sapphire and glass covers. But they look and perform identically only in the dark…

 

Lowering Screen Reflectance

The standard way that has generally been used to improve display performance in ambient light is to fight fire-with-fire and just continue increasing the display’s Maximum Brightness. But there is a practical limit to that, plus a brighter display needs more power and a bigger battery. With some new advanced technologies that will be introduced soon, the Reflectance of both Sapphire and Glass will be reduced significantly.

 

We’ll show that the best (and smartest) way to improve display performance, image contrast, color saturation, screen visibility and readability in ambient light is to lower the Screen Reflectance. Our test results and conclusions apply to all displays that are used in ambient lighting, including smartphones, smart watches, tablets, laptops, PC and video monitors, even TVs (if you watch during the day or with room lights on at night), and especially for displays that are mostly used in outdoor environments like digital signage and automobile displays.

 

Testing the Apple Watches

In this article we test and compare the display performance of an Apple Watch with a Sapphire Crystal to an Apple Watch Sport with Ion-X Glass. Although their internal OLED displays are identical, they have significant differences in optical performance due to the sapphire and glass covers. We’ll focus primarily on how differently they perform in ambient light with both Lab measurements and a side-by-side screen shot photo for a pure visual demonstration. We’ll cover all of the above issues and much more, with in-depth comprehensive display tests, measurements and analysis that you will find nowhere else.

 

The Display Shoot-Out

For in-depth testing and analysis of the OLED display on Apple Watch see our earlier Apple Watch OLED Display Technology Shoot-Out article. Also see our 2014 Smart Watch Display Shoot-Out article where we tested and compared the OLED display on the Samsung Gear 2 and the LCD display on the Sony SmartWatch 2. For this Display Shoot-Out article we are testing and comparing the Apple Watch with a Sapphire Crystal to an Apple Watch Sport with Ion-X Glass. To examine the display performance for the Apple Watches we ran our in-depth series of Mobile Display Technology Shoot-Out Lab tests and measurements in order to determine how the displays performed. 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. All the article results are from our DisplayMate High Ambient Light Display Test Lab, which can test displays at up to 80,000 lux with our proprietary instrumentation and test patterns.

 

 

Results Highlights

In this Results section we provide Highlights of the comprehensive DisplayMate Lab tests and measurements and extensive visual comparisons using test photos, test images, and test patterns that are covered in the advanced sections. The Display Shoot-Out Comparison Table summarizes the Apple Watch and Apple Watch Sport Lab measurements in the following categories: Screen ReflectionsBrightness and Contrast with Ambient LightColor Gamut with Ambient LightViewing Angle Variations. You can also skip these Highlights and go directly to the Apple Watch Sapphire vs Glass Conclusions.

 

Overview of the Apple Watch Displays

The Apple Watch comes in 3 models and two sizes – we tested the larger 42 mm Apple Watch model, which has a Sapphire crystal, and the 42mm Apple Watch Sport model, which has Ion-X Glass. Both models have an identical OLED display. See the Display Comparison Table for their detailed specs, and our earlier Apple Watch OLED Display Technology Shoot-Out article for an in-depth analysis of the OLED display.

 

Apple Watch Calibration

One very important and significant result from testing the two watch displays in the dark at 0 lux is that their photometry and colorimetry calibration measurements were both very good to excellent, and almost identical to one another, indicating a careful and accurate systematic factory calibration – Apple typically has each display individually calibrated. See the Brightness and Contrast and Color Gamut sections and Figure 1 for measurements and details.

 

Screen Reflectance

In the dark both Apple Watch displays appear and perform identically, but in ambient light they appear and perform differently due to the difference in the Reflectance of Sapphire and Glass.

 

For the Apple Watch Sport with Ion-X Glass we measured the Screen Reflectance to be 4.7 percent, while for the Apple Watch with Sapphire we measured 8.2 percent Screen Reflectance, which is 74 percent higher than with Glass. Both values are about 0.6 percent higher than just pure sapphire and glass alone, indicating that Apple has done an excellent job in optically bonding both the glass and sapphire to the OLED display without an air gap. See the Reflections section for measurements and details.

 

Performance in Ambient Light

The 74 percent higher Reflectance of the Apple Watch with Sapphire means that its screen will reflect almost twice as much surrounding ambient light as the Apple Watch Sport with Glass. And it takes surprisingly little ambient light for that to make a significant visible difference…

 

Contrast Decrease in Ambient Light

While the display Contrast Ratios are infinite at 0 lux absolute darkness, they decrease rapidly with ambient light. At just 500 lux, which is mid-range indoor ambient lighting, the display Contrast Ratios have fallen to just 29 with Glass and 17 with Sapphire. That is affected by the watch’s Light Sensor, which automatically dims the displays according to the current ambient light level. If we fool the Light Sensor and force the watches up to their Maximum Brightness of about 480 nits, the Contrast Ratios increase but are still only 64 with Glass and 38 with Sapphire at 500 lux. That’s indoors…

 

At an ambient light level of 2,000 lux, which corresponds to moderate outdoor lighting in the shade or an overcast sky, the display Contrast Ratios are just 12 with Glass and 7 with Sapphire. When we fool the Light Sensor up to Maximum Brightness, the Contrast Ratios increase but are still only 17 with Glass and 10 with Sapphire at 2,000 lux. However, Full Daylight that is not in direct sunlight ranges from 10,000 to 25,000 lux – for 10,000 lux the Contrast Ratios are 3 and 2 respectively. See the Brightness and Contrast with Ambient Light section for measurements and details.

 

Color Gamut Decrease in Ambient Light

While their Color Gamuts are both close to 100% of the sRGB/Rec.709 Standard Gamut at 0 lux absolute darkness as shown in Figure 1, the display Color Gamuts decrease with ambient light and are 82% with Glass and 69% with Sapphire at 500 lux, which is mid-range indoor ambient lighting. When we fool the Light Sensor up to Maximum Brightness the Color Gamuts are 93% and 85% respectively, as shown in Figure 2. That’s indoors…

 

At an ambient light level of 2,000 lux, which corresponds to moderate outdoor lighting in the shade or an overcast sky, the Color Gamuts are just 58% with Glass and 39% with Sapphire. When we fool the Light Sensor up to Maximum Brightness, the Color Gamuts are still only 68% with Glass and 54% with Sapphire at 2,000 lux. However, Full Daylight that is not in direct sunlight ranges from 10,000 to 25,000 lux, and the Gamuts will continue to decrease significantly with increasing ambient light. See the Color Gamut with Ambient Light section and Figure 2 for measurements and details.

 

Watch Viewing Angle Performance

For both the Sapphire and Glass displays we measured similar small to medium shifts in Brightness and Color with Viewing Angles up through 30 degrees. At much larger Viewing Angles sapphire shows larger shifts than glass. See the Viewing Angle Variations section for details.

 

Analyzing the Photo Below of the Watches in Ambient Light

The Lab tests quantitatively evaluate display performance with measurements of a large number of display parameters using specialized instruments and test patterns. Even if you like comparing Contrast Ratios, Color Gamuts, and other parameters, it’s also nice to see a screen shot of the displays under test to visually compare the results and differences.

 

The Photo below is a side-by-side screen shot of the Apple Watch Sport with Ion-X Glass on the left, and the Apple Watch with Sapphire on the right. They were taken together simultaneously inside an Integrating Hemisphere that provides a very uniform light distribution coming from all directions. The watches are sitting on a dark black background.

 

Photo Caption with Explanations

There are a number of important but subtle details that we will explain first. The Apple Watch on the right has a mirror stainless steel finish, so the lower portion of the case appears dark in the photo because it is providing a mirror reflection of the black background. The Apple Watch Sport on the left has anodized aluminum with a matte finish that diffusely reflects light from all directions and therefore has a more uniform appearance. So if you don’t look closely it looks as if the Apple Watch on the right is smaller, but it’s just an optical illusion from the differing brightness reflections from the cases. Also note that the mirror finish of the watch on the right is reflecting the Digital Crown and Side Button of the watch on the left.

 

In the dark both watches appear identical. The OLED displays have a perfect all black background, with white text and graphics, and a vibrant saturated red second hand.

 

The screen shot Photo below was taken at an ambient light level of 2,000 lux, which corresponds to moderate outdoor lighting in the shade or an overcast sky. Indoor residential lighting typically ranges from 100 to 500 lux, while office, commercial, and task lighting typically ranges 500 to 1,500 lux. Full Daylight that is not in direct sunlight ranges from 10,000 to 25,000 lux, while direct sunlight is 120,000 lux. To see how other displays perform in up to 40,000 lux see this article on Displays in High Ambient Light.

 

In the Photo below the ambient light penetrates and reflects from different layers in the display so some of its internal structures are visible. The OLED display itself is the inner rectangle in both watches. The background is much brighter on the right Sapphire display due to its 74% higher Reflectance compared to the Glass display on the left. The reflected ambient light reduces the image contrast of the white text and graphics, and also the color saturation and vibrancy of the red second hand. The large differences between displays are very obvious and striking.

 

Finally, on a technical note, the slight green tint visible in the photo for the Apple Watch with Sapphire on the right is due to a variation in its Reflectance Spectrum for ambient light, which is stronger in the green portion of the spectrum and weaker in the red and blue portions of the spectrum compared to the Apple Watch Sport with Glass display on the left. It is unlikely to be noticeable except possibly in high ambient light that is itself neutral in color. This effect does not occur with pure sapphire, so it is most likely due to something in the optical bonding and lamination of the sapphire to the OLED display.

 

Photo of the Apple Watches in 2,000 lux Uniform Ambient Light

Apple Watch Sport with Glass

Apple Watch with Sapphire

Apple Watch Sport with Glass

Apple Watch with Sapphire

Refer to the Photo Caption above for details

Click to Enlarge the Photo with Caption

 

 

 

Apple Watch Sapphire vs Glass Display Conclusions

The primary goal of this Display Technology Shoot-Out article series has always been to publicize and promote display excellence so that consumers, journalists and even manufacturers are aware of and appreciate the very best in displays and display technology. We point out which manufactures and display technologies are leading and advancing the state-of-the-art for displays by performing comprehensive and objective scientific Lab tests and measurements together with in-depth analysis. We point out who is leading, who is behind, who is improving, and sometimes (unfortunately) who is back pedaling… all based solely on the extensive objective careful Lab measurements that we also publish, so that everyone can judge the data for themselves as well… See the Display Shoot-Out Comparison Table for all of the Lab measurements and testing details, and the Results Highlights section above for a more general overview with explanations.

 

Apple Watch OLED Display

The Apple Watches have an excellent state-of-the-art OLED display that we analyzed in detail in our earlier Apple Watch OLED Display Technology Shoot-Out article. Refer to that article for an in-depth analysis of their OLED display.

 

Apple Watch and Apple Watch Sport Displays

For this article we have compared and analyzed the displays on the Apple Watch with a Sapphire Crystal and the Apple Watch Sport with Ion-X Glass. Both watches have the same OLED display, only the cover sapphire and glass are different, resulting in a large difference in their Screen Reflectance and performance in ambient light. One very important and significant result from testing the two watch displays in the dark at 0 lux is that their photometry and colorimetry calibration measurements were both very good to excellent, and almost identical to one another, indicating a careful and accurate systematic factory calibration – Apple typically has each display individually calibrated. See the Brightness and Contrast and Color Gamut sections and Figure 1 for measurements and details.

 

Different Screen Reflectance

In the dark both Apple Watch displays appear and perform identically, but in ambient light they appear and perform differently due to the difference in the Reflectance of Sapphire and Glass.

 

For the Apple Watch Sport with Ion-X Glass we measured the Screen Reflectance to be 4.7 percent, while for the Apple Watch with Sapphire we measured 8.2 percent Screen Reflectance, which is 74 percent higher than Glass. Both values are about 0.6 percent higher than just pure sapphire and glass alone, indicating that Apple has done an excellent job in optically bonding both the glass and sapphire to the OLED display without an air gap. See the Reflections section for measurements and details.

 

Both sapphire and glass each have many distinctive and important properties besides the Reflectance, and what is particularly interesting and relevant is that by using some new advanced technologies, the Reflectance of not only Sapphire but also Glass will be reduced significantly in the very near future for some displays, with major implications and improvements for both the visual and optical display performance, which we will discuss below.

 

Different Performance in Ambient Light

The 74 percent higher Reflectance of the Apple Watch with Sapphire means that its screen will reflect almost twice as much surrounding ambient light as the Apple Watch Sport with Glass. And it takes surprisingly little ambient light for that to make a visible difference…

 

Contrast Ratio:

While their Contrast Ratios are infinite at 0 lux absolute darkness, they decrease rapidly with ambient light. At just 500 lux, which is mid-range indoor ambient lighting, the display Contrast Ratios have fallen to just 64 with Glass and 38 with Sapphire (with the displays set to their Maximum Brightness of about 480 nits by fooling the Ambient Light Sensor, otherwise it is less than half the values). That’s indoors…

 

At an ambient light level of 2,000 lux, which corresponds to moderate outdoor lighting in the shade or an overcast sky, the display Contrast Ratios are just 17 with Glass and 10 with Sapphire (again with the displays set to their Maximum Brightness by fooling the Ambient Light Sensor, otherwise it is about 70% of the values). However, Full Daylight that is not in direct sunlight ranges from 10,000 to 25,000 lux – for 10,000 lux the Contrast Ratios are 3 and 2 respectively. See the Brightness and Contrast with Ambient Light section for measurements and details.

 

Color Gamut and Color Saturation:

While their Color Gamuts are both close to 100% of the sRGB/Rec.709 Standard Gamut at 0 lux absolute darkness as shown in Figure 1, they also decrease with ambient light. At just 500 lux, the Color Gamut is 93% with Glass and 85% with Sapphire (with the displays set to their Maximum Brightness of about 480 nits by fooling the Ambient Light Sensor, otherwise it is about 15% less), as shown in Figure 2. That’s indoors…

 

At an ambient light level of 2,000 lux, which corresponds to moderate outdoor lighting in the shade or an overcast sky, the Color Gamuts are just 68% with Glass and 54% with Sapphire (again with the displays set to their Maximum Brightness by fooling the Ambient Light Sensor, otherwise it is about 80% of the values). See the Color Gamut with Ambient Light section and Figure 2 for measurements and details.

 

Photo of the Displays in Ambient Light:

The Lab measurements like the Contrast Ratios and Color Gamuts above quantitatively evaluate display performance, but it’s also nice to see a screen shot of the displays under test to visually compare the results and differences. The Photo Above or this Photo Link is a side-by-side screen shot of the Apple Watch Sport with Ion-X Glass on the left, and the Apple Watch with Sapphire on the right. They were taken together simultaneously inside an Integrating Hemisphere that provides a very uniform light distribution coming from all directions at an ambient light level of 2,000 lux, which corresponds to moderate outdoor lighting in the shade or an overcast sky. See the Caption or the Photo Link for a detailed explanation of the photo.

 

Lowering the Reflectance of Sapphire and Glass

The standard way that has generally been used to improve display performance in ambient light is to fight fire-with-fire and just continue increasing the display’s Maximum Brightness. But there is a practical limit to that, plus a brighter display needs more power and a bigger battery. Clearly the best (and smartest) way to improve display performance, image contrast, color saturation, screen visibility and readability in ambient light is to lower the Screen Reflectance. In fact, it is the only way to turn the marginal Yellow Contrast and Gamut measurement results in the Display Shoot-Out Comparison Table into Green Very Good to Excellent performance levels. Plus, if you do that, the same display can be used at a lower Brightness setting, which will decrease the display power and increase the running time on battery.

 

In order to increase the use of sapphire for displays, the sapphire industry will need to modify the optical properties of sapphire without significantly affecting its scratch resistance and other mechanical properties. It can’t be done using traditional Anti-Reflection optical coatings which scratch easily.

 

With some new advanced technologies that will be introduced soon, the Reflectance of not only Sapphire but also Glass will be reduced significantly for some displays, and they will be available in the very near future, with major implications and improvements for both visual and optical display performance.

 

We will provide more information on Low Reflectance Sapphire and Glass in our upcoming 2015 Innovative Displays and Display Technologies article. Here is a link to the 2014 Edition. Follow DisplayMate on Twitter to learn about these developments and our upcoming display technology coverage.

 

The Next Steps in Display Performance Improvements in Ambient Light

Lowering the Screen Reflectance is just the first step in the upcoming major improvements of display performance in ambient light. The next steps will include using very wide Color Gamuts together with Dynamic Color Management and a Dynamic Intensity Scale that are both automatically adjusted real-time based on the measured current Ambient Light level in order to have them compensate for the reflected light glare and image wash out from ambient light as discussed above and in our 2014 Innovative Displays and Display Technology article.

 

All of these results and conclusions apply to all displays that are used in ambient light, including smartphones, smart watches, tablets, laptops, PC and video monitors, even TVs (if you watch during the day or with room lights on at night), and especially for displays that are mostly used in outdoor environments like digital signage and automobile displays.

 

The displays, technologies, and manufacturers that succeed in implementing these new high ambient light display performance strategies will take the lead in the next generations of displays… Follow DisplayMate on Twitter to learn about these developments and our upcoming display technology coverage.

 

 

The Apple Watches in Ambient Light

 

 

Display Shoot-Out Comparison Table

Below we examine in-depth the relative display performance of the Apple Watch that has a Sapphire Crystal with

the display on the Apple Watch Sport that has an Ion-X Cover Glass, using objective Lab measurement data and criteria.

 

The displays on both Apple Watches have the same OLED display with identical specifications except for the outer display cover, which is either Sapphire or Ion-X Glass and results in significant differences in optical performance that are analyzed below. For an in-depth analysis of the OLED display on Apple Watch display see our earlier Apple Watch OLED Display Technology Shoot-Out article.

 

For additional information on OLED display measurements see our Galaxy S6 Display Technology Shoot-Out article.

For comparisons with Samsung and Sony Smart Watches see our Smart Watch Display Technology Shoot-Out article.

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

 

Categories

Apple Watch 42 mm

with Sapphire Crystal

Apple Watch Sport 42 mm

with Ion-X Glass

Display Technology

Flexible OLED

RGB Stripe

Flexible OLED

RGB Stripe

Display Shape

4:5 = 0.80

Portrait Only

4:5 = 0.80

Portrait Only

Display Size

1.53 inches Diagonal

1.21 x 0.97 inches

with rounded corners

1.53 inches Diagonal

1.21 x 0.97 inches

with rounded corners

Display Area

1.2 square inches

1.2 square inches

Relative Display Area

100 percent

100 percent

Display Resolution

390 x 312 pixels

390 x 312 pixels

Total Number of Pixels

122K pixels

122K pixels

Pixels Per Inch

322 ppi

322 ppi

20/20 Vision Distance

where Pixels are Not Resolved

10.7 inches

10.7 inches

Appears Perfectly Sharp

at Typical Viewing Distances

Yes

Apple Retina Display

Yes

Apple Retina Display

Text and Graphics

Very Sharp

Very Sharp

Display Color Depth

Full 24-bit color

Full 24-bit color

 
Screen Reflections

The Screen Reflects Ambient Light, which washes out the Image Contrast and Colors.

The Average Reflectance is measured with an Integrating Hemisphere and Spectroradiometer.

The Mirror Reflections are measured with a highly collimated beam of light and Spectroradiometer.

The Reflectance of Sapphire is much higher than Glass.

Average Screen Reflection

Light from All Directions

 

with Sapphire

8.2 percent

Good

with Glass

4.7 percent

Excellent

Relative Brightness of the
Reflected Ambient Light

174 percent

Reflections Much Stronger

100 percent

Mirror Reflections

Percentage of Light Reflected

with Sapphire

9.2 percent

Good

with Glass

5.7 percent

Very Good

Contrast Rating for

High Ambient Light

The Higher the Better

with Sapphire

Up to 59   Good

Automatic Light Sensor

with Glass

Up to 101   Very Good

Automatic Light Sensor

 

Apple Watch with Sapphire

Apple Watch Sport with Glass

 

Brightness and Contrast with Ambient Light

At 0 degrees Viewing Angle.

But the typical Viewing Angle for a Watch is actually 30 degrees or more. See below.

Maximum Brightness

Measured in the dark at 0 lux

Up to 482 cd/m2

Automatic Light Sensor

  Up to 473 cd/m2

Automatic Light Sensor

Black Brightness at 0 lux

at Maximum Brightness

0 cd/m2 at 0 lox

Increases with Ambient Light

0 cd/m2 at 0 lux

Increases with Ambient Light

Contrast Ratio

Measured in the dark at 0 lux

Infinite at 0 lux

Decreases with Ambient Light

 Infinite at 0 lux

Decreases with Ambient Light

 

Auto Brightness Level

Measured in Ambient Light

Maximum Brightness Setting

 

with Automatic Light Sensor

  203 cd/m2  at     500 lux

  290 cd/m2  at  2,000 lux

  482 cd/m2  at    High lux

with Automatic Light Sensor

  217 cd/m2  at     500 lux

  323 cd/m2  at  2,000 lux

  473 cd/m2  at    High lux

Contrast Ratio

Measured in Ambient Light

Maximum Brightness Setting

 

 

 

with Automatic Light Sensor

17  at     500 lux

  7  at  2,000 lux

 

with Maximum Brightness

 38  at     500 lux

 10  at  2,000 lux

with Automatic Light Sensor

 29  at     500 lux

 12  at  2,000 lux

 

with Maximum Brightness

  64  at     500 lux

  17  at  2,000 lux

Relative Contrast Ratio

59 percent

Contrast Significantly Lower

100 percent

 

Apple Watch with Sapphire

Apple Watch Sport with Glass

 

Color Gamut with Ambient Light

The Image Colors depend on the Ambient Light and Viewing Angle.

Color of White

Color Temperature in degrees

Measured in the dark at 0 lux

7,145 K

Slightly Too Blue

Lower OLED Power Efficiency

7,085 K

Slightly Too Blue

Lower OLED Power Efficiency

Color Gamut

Measured in the dark at 0 lux

 

See Figure 1

 

104 percent at 0 lux

sRGB / Rec.709

Decreases with Ambient Light

 

See Figure 1

107 percent at 0 lux

sRGB / Rec.709

Decreases with Ambient Light

 

See Figure 1

Color Gamut

Measured in Ambient Light

 

See Figure 2

 

 

 

 

 

with Automatic Light Sensor

69 percent at     500 lux

39 percent at  2,000 lux

 

with Maximum Brightness

85 percent at     500 lux

54 percent at  2,000 lux

 

See Figure 2

with Automatic Light Sensor

82 percent at     500 lux

58 percent at  2,000 lux

 

with Maximum Brightness

93 percent at     500 lux

68 percent at  2,000 lux

 

See Figure 2

Relative Color Gamut

Gamut Significantly Smaller

Gamut Significantly Better

 

Apple Watch with Sapphire

Apple Watch Sport with Glass

 

Viewing Angle Variations

The typical Viewing Angle for a Watch is actually about 30 degrees or more from exactly face on.

See this Figure for an explanation and visual definition of JNCD.

Brightness Decrease

at a 30 degree Viewing Angle

 

with Sapphire

32  percent

Medium Decrease

with Glass

32  percent

Medium Decrease

Black Level Change

at a 30 degree Viewing Angle

0 percent

No Change for OLED

0 percent

No Change for OLED

White Point Color Shift

at a 30 degree Viewing Angle

 

Small Color Shift

Δ(u’v’) = 0.0102

2.5 JNCD with Sapphire

Small Color Shift

Δ(u’v’) = 0.0099

2.5 JNCD with Glass

Color Shifts

Primary Colors and Mixtures

at a 30 degree Viewing Angle

Medium Color Shift

Largest Shift Δ(u’v’) = 0.0375

9.4 JNCD with Sapphire

Medium Color Shift

Largest Shift Δ(u’v’) = 0.0397

9.9 JNCD with Glass

Categories

Apple Watch 42 mm

with Sapphire Crystal

 Apple Watch Sport 42 mm

with Ion-X Glass

 

 

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 displays can be significantly improved using DisplayMate’s proprietary very advanced scientific analysis and mathematical display modeling and optimization of the display hardware, factory calibration, and driver parameters. We help manufacturers with expert display procurement, prototype development, testing displays to meet contract specifications, and production quality control so that they don’t make mistakes similar to those that are exposed in our public Display Technology Shoot-Out series for consumers. This article is a lite version of our advanced scientific analysis – before the benefits of our DisplayMate Display Optimization Technology, which can correct or improve all of these issues. If you are a display or product manufacturer and want to significantly improve display performance for a competitive advantage then Contact DisplayMate Technologies.

 

About DisplayMate Technologies

DisplayMate Technologies specializes in proprietary advanced scientific display calibration and mathematical display optimization to deliver unsurpassed objective performance, picture quality and accuracy for all types of displays including video and computer monitors, projectors, HDTVs, mobile displays such as smartphones, smart watches, 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 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:  Apple Watch OLED Display Technology Shoot-Out

Article Links:  Smart Watch Display Shoot-Out for Samsung Gear 2 OLED and Sony SmartWatch 2 LCD

Article Links:  Absolute Color Accuracy Display Technology Shoot-Out

 

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

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

Article Links:  Display Technology News and Commentary

 

 

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