On Wednesday, David Washington, a senior program manager on Microsoft's User Experience team, detailed on the blog how Windows 8 will accommodate not only devices of various screen sizes and resolutions, but also screen densities.
Here are the three ways to measure a screen, and how Microsoft is addressing them in Windows 8.
Washington talked the least about screen size--the diagonal, corner-to-coner measurement of the display area of the screen. The screen sizes available in devices varies immensely, from 1 inch in small handheld devices to well over 600 inches in a stadium display. Microsoft is focusing on screens for three primary uses: "Slates" that tend to be 10.1 to 17 inches, "Workhorse PCs" typically from 12 to 15.6 inches, and "Family Hubs" that are either large monitors or, more commonly, high definition televisions 23 inches and larger. Windows 8, especially on the Metro interface, is designed to look and function well in all three scenarios.
Microsoft put a large amount of thought into screen resolution, which varies as much as screen size does. One of the most important considerations was in defining a minimum resolution of 1024 x 768 pixels required for the display of Metro apps. Washington pointed out that this would support 98.8 percent of Windows 7 installations, and that the minimum would make apps richer as well as prevent developers from having to test apps at resolutions below that. Similarly, to use the Snap feature, which allows multiple apps to share the screen, a minimum resolution of 1366 x 768 is required, which allows a 1024 pixel-wide app, as well as a 320 pixel-wide sidebar.
Relating to maximum resolution, Washington said, "You can run Metro style apps on a screen as big as 30 inches with a resolution of 2560 x 1600." Though it's unclear if this means Metro will not run on a higher resolution, it's more likely that this is an example of a large resolution that Metro supports.
Screen density as a measurement hasn't been used much until recently. Screen or pixel density refers to the number of pixels in a physical area, also known as dots per inch (DPI). Apple made the concept popular when it first introduced the Retina display in its iPhone 4, and about the 9.7-inch, 2048 x 1536 resolution, 264 DPI version in the new iPad. Since the new iPad has twice as many pixels in each dimension, screen elements in iOS are scaled up 200 percent so they don't look tiny, and remain touch friendly.
Windows 8 will support a much wider range of devices than iOS, so Microsoft is targeting three scaling factors that apps will automatically adjust to so they are appropriately sized on any screen: