Tablet and Smartphone Displays Under Bright Ambient Lighting Shoot-Out

Master Photo Grid for Viewing Screen Shots of all the Displays

Apple iPad 2 – Amazon Kindle Fire – Motorola Xoom – Samsung Galaxy Tab 10.1

Apple iPhone 4 – HTC Desire – Motorola Droid X – Nokia Lumia 900 – Samsung Galaxy S

Dr. Raymond M. Soneira

President, DisplayMate Technologies Corporation

Copyright © 1990-2012 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

The visual performance and viewability of Tablet and Smartphone displays in high Ambient Lighting is a specification that most consumers are not yet aware of or concerned about. Unfortunately, the same appears to be true for many of the manufacturers as well. While the displays all look about the same in the dark, as the Ambient Lighting levels increase, particularly outdoors, there are dramatic differences in screen viewability, which depend on a combination of each display’s inherent screen Brightness and screen Reflectance. It’s important because mobile devices are seldom used in the dark…

The Master Photo Grid below visually demonstrates the differences in Tablet and Smartphone display screen viewability over a very wide range of Ambient Lighting levels from Absolute Darkness up through very bright Sunlight. We photographed 4 Tablets and 5 Smartphones inside an Integrating Hemisphere using a powerful light source that uniformly illuminates the displays from all directions from 0 lux (Absolute Darkness) up through 40,000 lux (Indirect Sunlight), which is very bright. Direct Sunlight at noon is a blinding 100,000 lux.

The Master Photo Grid combines the Screen Shots from our Tablet Displays Under Bright Ambient Lighting Shoot-Out and Smartphone Displays Under Bright Ambient Lighting Shoot-Out articles in a compact format that makes visual comparisons and spotting trends very easy. A good way to see all of the Screen Shots at once without the need for horizontal scrolling is with a widescreen display that has at least 1920 pixels. Better yet, the iPad, iPhone, Windows Phones, and most Android Tablets and Smartphones will display all (or almost all) of the 72 Screen Shots on a single page in Portrait mode – you may need to pinch in the image to see a single screen view. In some cases you may need to double-tap the article text for optimum reading. This is the best way to see the large scale trends and differences in how the Tablet and Smartphone displays degrade as the Ambient Lighting levels increase.

Results Highlights

The Master Photo Grid below includes Screen Shots from many of the Tablets and Smartphones in our Mobile Display Technology Shoot-Out article series. For more information on how Ambient Lighting affects the displays read the Results Highlights for Tablets or the Results Highlights for Smartphones. The visual results from the Screen Shots agree very well with the Lab measured DisplayMate Contrast Rating for High Ambient Light for Tablets and the Contrast Rating for High Ambient Light for Smartphones. These Lab results are summarized in the Table below.

Trends to Notice: There are three major trends to follow in the Screen Shots as the Ambient Lighting levels increase:

1. The progressive increase in the brightness of what is supposed to be a black background.

2. The progressive loss of color saturation for the different intensity steps.

3. The progressive fading and disappearance of the dimmer intensity steps.

The Winner: The DisplayMate Contrast Rating for High Ambient Light for the displays ranges from a low of 15 (HTC Desire) to a high of 90 (Nokia Lumia 900). From both the Lab Measurements and the Screen Shot Viewing Tests (below) the top performing device for display viewability under Bright Ambient Lighting is the Nokia Lumia 900. This results from a combination of its high screen Brightness and low screen Reflectance, which Nokia calls ClearBlack technology. The Samsung Galaxy S and Apple iPhone 4 are tied for second place. The best Tablets all performed a notch below the Smartphones – the Samsung Galaxy Tab 10.1 was the leader, with the iPad 2 in second place. The new iPad (not included below) performs better than the iPad 2 and just behind the Galaxy Tab 10.1. The other Smartphones and Tablets performed well below these top models – ALL manufacturers need to pay much more attention to their display performance in high Ambient Lighting because that is frequently how they are used. The highly touted and advertised display Contrast Ratio applies only to Absolute Darkness, which makes it pretty much irrelevant for mobile devices. Note that we plan on including the Lumia 900 in one of our upcoming Smartphone Shoot-Outs.

Overview and Legend

The Master Photo Grid has 4 Tablets and 5 Smartphones arranged vertically – with the best performing units listed top to bottom by category.

There are Screen Shots for 8 Ambient Light Levels from 0 lux (Absolute Darkness) to 40,000 lux (Indirect Outdoor Sunlight) arranged horizontally.

The visual Screen Shots agree well with the Lab Measurements.

The Lab Measurements for each Tablet and Smartphone are listed on the left for each device:

CR HAL is the DisplayMate Contrast Rating for High Ambient Light – which is based on the measured Screen Brightness and Screen Reflectance.

Below CR HAL is the Peak White display Brightness (Luminance) in cd/m2. Both can vary if the display has Dynamic Brightness or Dynamic Contrast.

The values listed are for the test image shown below. The next R = entry provides the measured Screen Reflectance in percent.

For background, in-depth explanations and analysis be sure to read the complete original articles: