Tuesday, July 15, 2003
Show Me The Pixels! The Importance of PPI
Posted by Jason Dunn in "THOUGHT" @ 11:00 AM
I was thinking about the issue of enhancing the Pocket PCs resolution again, especially in light of the recent announcement yesterday of small PDA screens reaching 800 x 600 resolution soon. I can't find a reference to this on Google, but I remember reading that the clarity of printed text on a page is equal to around 300 ppi. That sounds about right to me - 300 dpi laser printed text looks much better than 150 dpi, but about the same as 600 dpi text, so I think that's the human sensory threshold. So let's break this down...
• The Pocket PC at 320 x 240, with a 3.5" screen has a 110 ppi.
• The Pocket PC at 320 x 240, with a 4" screen (Genio) has a 100 ppi. That 10 ppi makes a difference if you can believe it - I even noticed it when I looked at the screen. Text looked a little bit "blockier". People also comment regularly that the text on the iPAQ 1910 looks a little sharper and crisper than the text on the iPAQ 5450.
• The newest Sony Clie at 320 x 480 with a 3.5" screen (I scoured Google and couldn't find the exact screen size, but it's got to be close to that) has double the number of pixels a Pocket PC, so the ppi value is around 164 or so. Looking at text on the Clie is nicer than looking at text on a Pocket PC.
If we were to get the Pocket PC to 640 x 480 resolution on a 3.5" screen, we'd hit 229 ppi. :-) 300 ppi is the holy grail of LCD display crispness, and I think smaller devices will reach it before desktop monitors do. Although the screen resolution of Pocket PCs is certainly "good enough" for most things, I was really blown away by the crispness of the text on the Clie devices. Same thing with the Zire 71 - the text was very sharp and easy to read.
The problem is that we can't just up the resolution - if we double the resolution on the Pocket PC, everything will get twice as small. That might be useful for some people, but it's not a good solution overall. What we really need is a resolution-independent operating system. One that has a relative size setting for a variety of resolutions, with font and icon settings that will grow proportionately. It's just like having a higher resolution on your desktop screen - the more pixels are using to draw each item, the crisper and cleaner it will look. But the more pixels is used to draw something, the smaller it gets - I know, it makes no sense. :|
This issue affects every desktop computer too - Windows desperately needs the same functionality. 1600 x 1200 resolution on a 15" screen requires excellent eyesight to use, because there's no easy way to say "make everything on the screen bigger". You can adjust the DPI, but while it makes everything bigger, it also drops the quality of the displayed items.
This whole topic makes my head hurt (hopefully I got it all right), but the bottom line is that we need 640 x 480 on our Pocket PCs, and an operating system that will support it in a slick fashion. Microsoft, we're waiting. :way to go:
• The Pocket PC at 320 x 240, with a 3.5" screen has a 110 ppi.
• The Pocket PC at 320 x 240, with a 4" screen (Genio) has a 100 ppi. That 10 ppi makes a difference if you can believe it - I even noticed it when I looked at the screen. Text looked a little bit "blockier". People also comment regularly that the text on the iPAQ 1910 looks a little sharper and crisper than the text on the iPAQ 5450.
• The newest Sony Clie at 320 x 480 with a 3.5" screen (I scoured Google and couldn't find the exact screen size, but it's got to be close to that) has double the number of pixels a Pocket PC, so the ppi value is around 164 or so. Looking at text on the Clie is nicer than looking at text on a Pocket PC.
If we were to get the Pocket PC to 640 x 480 resolution on a 3.5" screen, we'd hit 229 ppi. :-) 300 ppi is the holy grail of LCD display crispness, and I think smaller devices will reach it before desktop monitors do. Although the screen resolution of Pocket PCs is certainly "good enough" for most things, I was really blown away by the crispness of the text on the Clie devices. Same thing with the Zire 71 - the text was very sharp and easy to read.
The problem is that we can't just up the resolution - if we double the resolution on the Pocket PC, everything will get twice as small. That might be useful for some people, but it's not a good solution overall. What we really need is a resolution-independent operating system. One that has a relative size setting for a variety of resolutions, with font and icon settings that will grow proportionately. It's just like having a higher resolution on your desktop screen - the more pixels are using to draw each item, the crisper and cleaner it will look. But the more pixels is used to draw something, the smaller it gets - I know, it makes no sense. :|
This issue affects every desktop computer too - Windows desperately needs the same functionality. 1600 x 1200 resolution on a 15" screen requires excellent eyesight to use, because there's no easy way to say "make everything on the screen bigger". You can adjust the DPI, but while it makes everything bigger, it also drops the quality of the displayed items.
This whole topic makes my head hurt (hopefully I got it all right), but the bottom line is that we need 640 x 480 on our Pocket PCs, and an operating system that will support it in a slick fashion. Microsoft, we're waiting. :way to go:
