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Re: [css3-values][css3-mediaqueries] resolution in dpi / dppx

From: Øyvind Stenhaug <oyvinds@opera.com>
Date: Tue, 29 Jan 2013 12:14:12 +0100
To: "Johannes Koch" <koch@w3development.de>, "www-style@w3.org" <www-style@w3.org>, François REMY <francois.remy.dev@outlook.com>
Cc: Fantasai <fantasai.lists@inkedblade.net>
Message-ID: <op.wrn6tyrcbunlto@oyvinds-desktop>
On Mon, 28 Jan 2013 20:00:43 +0100, François REMY  
<francois.remy.dev@outlook.com> wrote:

>> For instance, if we say the viewing distance is about half an arms  
>> length
>> then the size of a reference pixel would be about 1/128 physical inches.
>> Given 312 device pixels per physical inch, this gives 312/128 = 2.4375
>> device pixels per reference pixel.

Sorry, as I was waiting for the bus home yesterday it occurred to me that  
I had written something wrong... I should probably be more careful with  
arithmetic so late in the afternoon :) Not sure where the 1/128 came from,  
it should of course be 1/192 (half of 1/96). Though 312/192 = 1.625 still  
rounds to 2, and with Kenneth's percentages it would as well (60% would  
give 1.95 and 70% would give 2.275).

> Thanks for the clarification. Is there an online calculator that gives  
> the optimal size of a pixel (or the DPI) given the viewing distance? 		

Not that I know, but it's basically just a linear relationship with a 1/96  
inch pixel size at 28 inches viewing distance, as indicated by other posts.

Øyvind Stenhaug
Opera Software ASA
Received on Tuesday, 29 January 2013 11:14:46 UTC

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