Why EDID is not trustworthy for DPI

Nicolas Mailhot nicolas.mailhot at laposte.net
Thu Oct 6 20:03:21 UTC 2011

Le jeudi 06 octobre 2011 à 15:39 -0400, Felix Miata a écrit :

> Instead, display fonts of different sizes and have user pick one. No need for 
> user to know or care about units or numbers or DPI,

That does not work because those units are used in different electronic
formats, for example office suites. You can invent all the new font
mesurements you want at the end of the day a lot of users will open
libreoffice or another app that requires them to know the size of a 12pt
font. All you get by using another unit elsewhere is a new translation
table and lots of confused users. (you can replace office suite with
blog + custom css that works well on your computer but is hideously
small/large when you check your site from you ma's computer)

After all the 'need to hide dpi and units' madness started many users
started to use custom font scales on their computer, and got really
annoyed when they realised later that:
1. changing their hardware changed the meaning of all the sizes they got
used to
2. they could not agree with their friends what sizes meant, and the
office documents they had to produce where missized

That's the same reason you need to colour correct your screen if you're
serious about photography. In theory your screen colour drift does not
mater because you can compensate for it camera-size. In practice the
compensation ends up as huge colour mistakes as soon as you try to use
the result on something else (another screen, printing the result, does
not matter if you don't stick to a common non local baseline things will

Nicolas Mailhot

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