4 comments on this post.

1. Annonymous Coward says:

   March 5, 2009 at 4:26 pm

   1400×1050 res 14″ screen on my t42 is the only thing keeping me from upgrading to newer hardware, all these 13″ 1280×800 displays that seem to have become standard just have way too little real-estate and are not sharp enough. One would think manufacturers would give sharper displays as tech progressed, i think the colors, contrast and response time on todays displays are good enough. Lets please focus on getting some more sharpness at the consumer level (ie. not the insanely priced pro stuff),

   and less glossy screens on laptops would be appreciated too, goddamn shiny screens are impossible to use outdoors, and need to be cleaned twice as often.

   some things just seem to be getting worse, damn ignorant consumerism driven society where every one needs to have the latest piece of shit. Seriously people! Raise your demands, and dont buy the stuff that doesn’t meet them, only way to get the companies to deliver truly better products, instead of selling you marketing hype with bloated operating systems to give the illusion of better performance while surfing the web and word-processing!

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2. Drummer says:

   March 4, 2009 at 12:50 am

   When did Thousands of Pixels Per Square Inch [TPPSI] become a factor of any importance? I can understand linear resolution (DPI), which the author seems to completely ignore.
   DPI measurements and their applied use help us make sure that the WYSIWYG word processors, drawing programs, etc. accurately represent the final printed page(s). TPPSI is not a measurement used in graphical environments.

   He also seems to assume that the pixels are square. This is not necessarily the case. For computers though, it usually is. IF that is the case, then the Dots Per Inch [DPI] can be derived from his figures by taking the square-root of the given numbers. For example, 17.8 TPPSI translates to roughly 133 DPI, or nearly the equivalent of old dot-matrix printers in high-quality mode.

   To calculate the DPI, take the square root of the sum of the squares of the number of pixels (horizontally and vertically) and divide that by the number of inches diagonally. In the 1024×600 8.9″ display that becomes:

   (1024×1024) = 1048578
   (600×600) = 360000
   (1048578+360000) = 1408576
   sqrt (1408576) = 1186.8344
   (1186.8344 / 8.9) = 133.35 DPI

   But no matter how big the screen, 1024 pixels across is STILL 1024 pixels across. (This fact seems to be lost on most men with “big screen” TVs, where the resolution is defined by the medium – the pixels just get bigger, not clearer.)

   With that said, I’d take a 15″ screen with a 1024 pixel width (85 DPI) over a 8.9″ screen with a 1024 pixel width (133 DPI) for nearly everything I do. The latter may be “sharper” but reading a page without magnifying glasses is a LOT less stress.

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3. Polymath says:

   March 3, 2009 at 8:39 pm

   The correlation between size and TPPSI is -0.40. That’s a fairly large correlation that says that as the size goes down, the pixel density goes up… which is what you would expect when you have wildly varying screen sizes and modestly varying display resolutions.

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4. Durentis says:

   March 3, 2009 at 7:55 pm

   “The number of pixels is irrelevant on its own;”

   Nonsense. The pixel count gives you the aspect ratio (4:3, 16:9, 16:10, and so on with little variation). The diagonal length fits the aspect ratio. How many laptop/netbook screens don’t follow this standard?

   http://en.wikipedia.org/wiki/File:Vector_Video_Standards2.svg

   “you need to know what the pixel density”

   No, I don’t. I need to know the number of pixels the screen can support. Will my document width fit on the screen? Can I fit two side by side? The answer lies in pixel count. Given a window that shows certain information, pixel density affects the size of that window in inches (are my eyes good enough to see a tiny window?) whereas pixel count affects the size of the window in pixels (number of pixels required to show all the information regardless of density).

   “The screen size is important, but not the diagonal size.”

   1 != (2-1). Gotcha. (No.) I don’t think you’re saying what you think you’re saying because that’s a simple contradiction.

   “Theoretically, an 8.9? screen could range from practically zero square inches to over 35 square inches.”

   Practically, screens follow standard aspect ratios such that an 8.9″ screen will fit one of the aspect ratios.

   “Luckily, it is possible to use the given information to get a rough (but decent) estimate of the number of pixels per square inch.”

   Good thing. It’s important to make sure that your 1920×1080 15″ screen has a higher pixel density than your 1920×1080 20″ screen. Wouldn’t want to get ripped off, after all. But isn’t that fact trivial?

   “Check out the comparison below: [...]
   Interpret this as you will, it is very interesting to see that the pixel density usually has nothing to do with the size.”

   First, comparisons MUST minimize variables. You have 5 examples with 4 different resolutions on 4 screen sizes. Though you can still verify the trivial facts from them:
   - Screen size goes up with same resolution, TPPSI goes down
   - Screen size goes down with same resolution, TPPSI goes up
   - Resolution goes up on same screen size, TPPSI goes up
   - Resolution goes down on same screen size, TPPSI goes down

   That said, I do want high pixel densities. Not because the figure ‘pixel density’ is important to me, but because I want (W)UXGA+ resolutions on <=15″ screens and that implies that I want densely packed pixels. I want more real estate on smaller devices and have the eye sight to make use of it.

   ‘Pixel density’ is a manufacturer concern not a consumer concern.

   Seriously.. did someone mention ‘Pixel Density’ and it sounded cool?

   NB: Resolution above refers to a screen’s maximum/native resolution.

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