The new Windows tablets, led by Microsoft's Surface, provide a third major family of tablets for consumers and the computing world. The significance and stakes are enormous because tablets are among the most important developments in computing and consumer products in the last 20 years. Like Google's Android tablets, the Windows tablets will be made by many different manufacturers. And just like Google's Nexus, which provides reference designs for the Android product line, Microsoft is producing its own Surface tablets for the Windows product line.
With large numbers of tablets and smartphones running virtually identical software, the display becomes the single most important way for manufacturers to differentiate their products — that's been true for Android and the same will apply for Windows devices. A top-notch display makes everything that runs on a tablet or smartphone look great or as good as possible — including all of the Apps, web content, photos, and videos — looking a lot better than on devices with inferior displays. The inferior displays will be either cheap low-end displays, or expensive displays manufactured with bad parameter choices, or high quality displays ruined through improper calibration at the factory. It will be interesting to see which manufacturers play for the top, and those that try to get away with playing the bottom.
So which one is Surface RT? And how much will it matter?
Dr Raymond Soneira of DisplayMate Technologies has made it his mission to suss out the best smartphone, tablet, HDTV and multimedia displays from the worst with his Display Technology Shoot-Out series. Here, Microsoft's Surface RT dukes it out with the competition.
The Microsoft Surface and all Windows tablets are coming in two versions: the just launched Windows RT with a 1366x768 display that we test here, and the Windows Pro tablets with a 1920x1080 display that will launch in early 2013. In this Display Shoot-Out we'll tell you all about the Microsoft Surface display with extensive Lab measurements, viewing tests and objective in-depth analysis. For other aspects including its OS, apps, and overall operation and functionality you will need to refer to reviews that cover these issues in detail but generally provide little information about the display.
To examine the performance of the Microsoft Surface RT, we ran our in-depth series of Mobile Display Technology Shoot-Out tests and compared it to Apple iPad 3 and the Samsung Galaxy Tab 10.1. The Galaxy Tab 10.1 was chosen for this Shoot-Out because it has the best display performance for the standard resolution 10-inch Android tablets in our Display Shoot-Out series. The Apple iPad 2 is also included in the comparisons.
We take display quality very seriously and provide in-depth objective analysis side-by-side comparisons based on detailed laboratory measurements and extensive viewing tests with both test patterns and test images. For additional background and information see the iPad Display Technology Shoot-Out article that compares the iPad 2 and the new iPad 3, the 10-inch tablet Display Technology Shoot-Out that compares five "popular" full-size tablets, and the 7-inch tablet Display Technology Shoot-Out that compares the Amazon Kindle Fire HD and the Google Nexus 7.
In this Results section we provide highlights of the comprehensive lab measurements and extensive side-by-side visual comparisons using test photos, test images and test patterns that are presented in later sections. The Comparison Table in the following section summarises the Lab measurements in the following categories: Screen Reflections, Brightness and Contrast, Colours and Intensities, Viewing Angles, Display Backlight Power Consumption, Running Time on Battery. You can also skip the highlights and go directly to the conclusions.
Sharpness and Resolution
The Surface RT screen resolution of 1366x768 pixels is comparable to most existing tablets, but many of the latest tablets have been launching at 1920x1080 or above, which provides double the total number of pixels, and 50 per cent greater pixels per inch or more. Specs aside, what is the actual visual significance of the lower pixel count? Most consumers are unlikely to notice much of a visual difference in photos and videos because they are inherently fuzzy — it's really only critical for providing visually sharp text.
The Surface RT uses sub-pixel rendering (called ClearType in Microsoft's implementation) that in our tests significantly improves the visual sharpness of text over standard Pixel Rendering that is used in most mobile displays. In our comparison tests, text on the Surface RT was significantly sharper than on the iPad 2 and all 1280x800 10-inch Android tablets, but it wasn't as sharp as the iPad 3.
The screens on almost all tablets and smartphones are mirrors good enough to use for personal grooming. Even in moderate ambient lighting the image contrast and colours can noticeably degrade from ambient light reflected by the screen, washing out the images and colours and producing distracting mirror reflections superimposed on the screen. So low reflectance is extremely important in determining real-world picture quality. The lower the better…
Our lab measurements found the Surface RT to have the lowest screen reflectance of any tablet in our Display Shoot-Out article series. The Surface RT also has the highest contrast rating for high ambient light for tablets, which quantitatively measures screen visibility under bright ambient lighting — the higher the better… This article has screenshots that show how screen images degrade in high ambient lighting.
Colour Gamut and Colour Accuracy
While the display pixels per inch and pixel resolution seem to get most of the attention, it is the display's colour gamut together with the factory display calibration (below) that play the most important role in determining the wow factor and true picture quality and colour accuracy of a display. The colour gamut is the range of colours that a display can produce. If you want to see accurate colours in photos, videos and all standard consumer content the display needs to closely match the standard colour gamut that was used to produce the content, which is called sRGB / Rec.709. Most of the existing LCD tablets and smartphones have smaller colour gamuts around 60 per cent of the standard gamut, which produces somewhat subdued colours. The main reason for providing a smaller colour gamut is to improve screen brightness, power efficiency and battery running time, which is important for many users.
The Surface RT has a smaller 57 per cent colour gamut, which is disappointing in an otherwise excellent set of display performance specifications. While that‘s comparable to most existing LCDs in tablets and smartphones, many mobile displays are now coming with larger colour gamuts from 80 to 100 per cent, which significantly improves colour saturation, accuracy and vividness.
Factory Display Calibration
The raw LCD panel hardware first needs to be adjusted and calibrated at the factory with specialised firmware and software data that are downloaded into the device in order for the display to produce a usable image — let alone an accurate and beautiful one. This is actually a science but most manufacturers seem to treat it as if it were a modern art form, so few tablets, smartphones, and even HDTVs produce accurate high-quality images.
Microsoft has paid careful attention to factory display calibration unlike most other manufacturers — including most of the Android and Nexus devices that we have tested. The Surface RT has an accurate white point and an accurate intensity scale, which are both very important for accurate image reproduction. Apple has been a leader in accurate display calibration, but all of the iPads and iPhones that we have tested have white points that are slightly too blue, which can impart a cold or bluish caste to some images — such as in shifting the complexions of faces slightly.
Using our extensive library of challenging test and calibration photos, we compared the Surface RT to a calibrated professional studio monitor and to the new iPad 3, which has a virtually perfect factory calibration and colour gamut.
Images on the Surface RT were accurate with good contrast, but with somewhat subdued colours like most existing tablets and smartphones due to its smaller colour gamut. As a result, the Surface RT display was unable to produce very saturated colours, like fire engine red, which was not as vibrant and appeared with a noticeable shift towards orange. Very saturated purples are also especially difficult to reproduce on LCD displays with a reduced colour gamut. For example, the Surface RT appeared almost identical to the iPad 2 in this screenshot comparing the iPad 2 to the new iPad 3.
Conclusions for the Microsoft Surface RT Display
The display on the Microsoft Surface RT outperforms all of the standard resolution full-size 10-inch tablets that we have tested in our Display Shoot-Out series. The lab tests and measurements documented in the Shoot-Out Comparison Table below indicate that Microsoft has paid a lot of attention to display performance for the Surface RT. In particular, on-screen text is significantly sharper, it has a better factory display calibration, and also significantly lower screen reflectance than the iPad 2 and all full size 1280x800 Android tablets. But it is not as sharp as the iPad 3 or 4, nor does it have their large full colour gamut. We'll have to wait for the high resolution Windows Pro tablets that will be launching in early 2013 for direct comparisons with the high-resolution iPads and Android tablets. This is a great start for Windows tablets and brings much-needed competition to the tablet marketplace. In addition, many other manufacturers will be launching their own branded Windows RT and Pro tablets — we'll include the best of them in future Mobile Display Shoot-Outs.
Before we discuss the comparisons with the Apple iPads and Android tablets we'll first discuss the principal issues for the Surface RT display. The test and measurement details are provided in the Comparison Table below.
The 1366x768 Surface RT screen resolution has been the source for lots of discussions. While it's comparable to most existing tablets, many of the latest tablets have been launching at 1920x1080 or above, which provide double the total number of pixels, and 50 per cent greater pixels per inch or more. Specs aside, what is the actual visual significance of the lower pixel count? While most consumers are unlikely to notice much of a visual difference in photos and videos because they are inherently fuzzy, where the higher pixel counts can make a big difference is with small text and fine graphics.
Enhanced Screen Sharpness
While screen resolution gets lots of attention from both consumers and marketers — it's really only critical for providing visually sharp text — but that applies for most applications running on a tablet. As we have pointed out, a number of times, the best way to increase text visual sharpness on any display is by using sub-pixel rendering (performed in software). Surface RT and all Windows displays use sub-pixel rendering (called ClearType in Microsoft's implementation) that in our tests significantly improved the visual sharpness of text over standard pixel rendering that is used in most mobile displays — see the comparisons below. Finally, if the lower screen resolution spec is an issue, simply wait for the Surface Pro and Window Pro tablets with 1920x1080 resolution that will launch in early 2013. With their ClearType sub-pixel rendering they should provide visual text sharpness that is comparable to the highest-resolution tablet displays being introduced.
Low Screen Reflectance
Low Screen Reflectance is very important because tablets are almost never viewed in the dark, so screen reflections often significantly degrade image quality, colour accuracy and screen readability — washing out the images and colours and producing distracting mirror reflections superimposed on the screen. As a result, low screen reflectance is extremely important for real-world visual display performance and image quality. It also allows the display to run with lower screen brightness settings, which extends the battery running time. Our lab measurements found the Surface RT to have the lowest screen reflectance of any tablet in our Display Shoot-Out article series. For comparison, the iPad 3 reflects 33 per cent more ambient light than the Surface RT and the Galaxy Tab 10.1 reflects 41 per cent more. Mirror reflections are 52 per cent and 62 per cent brighter than the Surface RT. The Surface RT also has the highest contrast rating for high ambient light for tablets, which quantitatively measures screen visibility under bright ambient lighting — the higher the better… This article has screenshots that show how screen images degrade in high ambient lighting.
Smaller Colour Gamut
The Surface RT has a smaller 57 per cent colour gamut, which is disappointing in an otherwise excellent set of display performance specifications. While that‘s comparable to most existing LCDs in tablets and smartphones, many mobile displays are now coming with larger colour gamuts from 80 to 100 per cent of the sRGB / Rec.709 Standard, which significantly improves colour saturation, accuracy and vividness. The subdued colours were quite apparent in our photo comparison tests. The main reason for providing a smaller colour gamut is to improve screen brightness, power efficiency and battery running time. In that regard, the Surface RT has the second longest battery running time at maximum brightness for any tablet that we have tested — for many users that will be considered a good strategic tradeoff.
Comparisons with the Android Tablets
The Surface RT out performs the displays on all of the full-size 10-inch 1280x800 Android tablets that we have tested. However, the 7 inch Amazon Kindle Fire HD and Google Nexus 7 have a larger 86 per cent colour gamut and much higher pixels per inch screens. In terms of visual sharpness, the Surface RT with ClearType sub-pixel rendering improves text sharpness significantly so that it is significantly sharper than the Galaxy Tab 10.1 and other 10-inch 1280x800 tablets, but not quite as sharp as the 7-inch Kindle Fire HD and Nexus 7 in our visual comparison tests. The Kindle Fire HD has a very good factory calibration like the Surface RT (but the Nexus 7 does not). We'll compare the 1920x1200 Android tablets with the 1920x1080 Surface Pro in a future Display Shoot-Out. For details see the 10-inch tablet Display Technology Shoot-Out and the 7-inch Tablet Display Technology Shoot-Out.
Comparisons with the Apple iPads
The Surface RT out performs the display on the iPad 2 across the board except for the colour Gamut. The Surface RT is comparable or better than the iPad 3 in all test categories except two: screen resolution and colour gamut. The iPad 3 has a much higher resolution of 2048x1536 and a much larger 99 per cent colour gamut. In terms of visual sharpness, the Surface RT with ClearType sub-pixel rendering improves text sharpness significantly so that it is significantly sharper than the iPad 2, but not as sharp as the iPad 3. In terms of the colour gamut, the new iPad 3 has significantly better colour saturation and colour accuracy. While the Surface RT colour gamut is similar to the iPad 2, the iPad 2 has somewhat better colour saturation because of its steeper intensity scale and gamma (as explained in Figure 3 below). For details see the new iPad 3 and iPad 2 Display Technology Shoot-Out.
The Next Generation of Tablet Displays
See our new iPad Shoot-Out Conclusion for a discussion of the many improvements that are needed for the next generation of tablet displays.
Display Shoot-Out Comparison Table
Here we compare the display on the Microsoft Surface RT to the Apple iPad 3 and the Samsung Galaxy Tab 10.1 based on objective measurement data and criteria. We also include some comparisons with the Apple iPad 2. The Samsung Galaxy Tab 10.1 was chosen because it has the best display performance for the standard resolution 10-inch Android tablets in our Display Shoot-Out series. Note that the tablets were all purchased independently by DisplayMate Technologies through standard retail channels.
For additional background and information see the iPad Display Technology Shoot-Out article that compares the iPad 2 and the new iPad 3, the 10-nch Tablet Display Technology Shoot-Out that compares five "popular" full-size Tablets, and the 7-inch Tablet Display Technology Shoot-Out that compares the Amazon Kindle Fire HD and the Google Nexus 7.
Dr Raymond Soneira is President of DisplayMate Technologies Corporation of Amherst, New Hampshire, which produces video 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 PhD in Theoretical Physics from Princeton University, spent five years as a Long-Term Member of the world famous Institute for Advanced Study in Princeton, another fiveyears as a Principal Investigator in the Computer Systems Research Laboratory at AT&T Bell Laboratories, and has also designed, tested and installed colour 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 [email protected].
DisplayMate Technologies specialises in advanced mathematical display technology optimisations and precision analytical scientific display diagnostics and calibrations to deliver outstanding image and picture quality and accuracy — while increasing the effective visual contrast ratio of the display and producing a higher calibrated brightness than is achievable with traditional calibration methods. This also decreases display power requirements and increases the battery run time in mobile displays. This article is a lite version of our intensive scientific analysis of smartphone and mobile displays — before the benefits of our advanced mathematical DisplayMate Display Optimisation Technology, which can correct or improve many of the deficiencies — including higher calibrated brightness, power efficiency, effective screen contrast, picture quality and colour and greyscale accuracy under both bright and dim ambient light, and much more. Our advanced scientific optimizations can make lower cost panels look as good or better than more expensive higher performance displays. For more information on our technology see the summary description of our Adaptive Variable Metric Display Optimiser AVDO. If you are a display or product manufacturer and want our expertise and technology to turn your display into a spectacular one to surpass your competition, contact DisplayMate Technologies to learn more.
This article has been republished with permission from DisplayMate.com, where it can be read in its entirety.