Nick Fitzsimons wrote Fri, 6 Jan 2006 10:29:22 -0000 (GMT):
> On 05.01.2006 23:54, Duckworth, Nigel wrote:
> > Since MSIE/PC is working internally in points,
> > it's default font size is always 12pt.
> Actually, all modern browsers (Firefox, IE, Opera, Safari, Konqueror)
> start with a "factory setting" font-size of 16px,
They do not!
The major browser makers decided long ago that matching IE was in their
best interest. That means nearly all start at or close to 16px, but how
they get that way, how close the match, and how easy it is for users to
adjust away from it varies.
At least as far back as IE4, IE has been and remains 12pt by default. No
matter what OS customizations are made, it remains 12pt. Doze provides
"display properties" -> "settings" -> "advanced" -> "display" -> "DPI
setting" so that if a user's screen resolution makes screen items too
small to view comfortably, he can increase the DPI to compensate. Among
the selections are:
"Normal size (96 DPI)" (which was labeled "small" prior to XP)
"Large size (120 DPI)"
"Custom setting"
Choosing custom, the list selections are:
"75%" (72 DPI)
"100%" (96 DPI)
"125%" (120 DPI)
"150%" (144 DPI)
"200%" (192 DPI)
plus an option to drag a scale with the mouse pointer to achieve other
settings.
Unlike Linux, doze does not very well support the selections actually
made, actually using closest step match when the scale is used, and
worse in doze versions prior to XP.
Choosing the 5 main options, the corresponding px values of the 12pt
default are:
72 - 12px
96 - 16px
120 - 20px
144 - 24px
192 - 32px
As shipped, doze always has used 96 DPI, thus making 12pt=16px. This is
the initial reason why web designers began the mantra that "the defaults
are too big". This was in fact almost universally true back when the
default resolution was 640x480, few used the 800x600 option, and almost
nobody used the maxiumum of 1024x768.
Later, when the default resolution was changed to 800x600, more people
were using 1024x768 than the 800x600 default, and many others were using
resolutions as high as 3000px wide, the mantra failed to change. At
1024x768, 16px is only 5/8 the height of 16px on a 640x480 display. A
17" display is only 23% taller than a 14" display, so the larger recent
average display size doesn't come close to making up the difference. In
the other direction, in spite of larger displays, with resolutions like
1792x1344 and more, 16px can be physically smaller than 9px or 10px is
on common resolutions.
Now makers of high resolution laptops are shipping with the DPI at 120
instead of 96, making their IE default 20px. Shipments of new laptops
now outnumber shipments of new desktops, and it is mostly because of
this that we can no longer honestly say that "all modern browsers ...
start with a "factory setting" font-size of 16px".
As you can see, doze recognizes that not all users are alike, and
enables users who need bigger fonts to have them. The reasons vary.
Sometimes it's visual acuity, sometimes high resolution, sometimes no
particular reason, sometimes a combination, but the fact is everyone
isn't the same, and treating people who don't find defaults acceptable
by arbitrarily setting web page text size to some non-default value
amounts to discrimination against them.
Most browsers other than IE, whether for doze or Linux or Mac or other,
traditionally have done like the word processing programs and other
software and the print media and set sizes in pt. For all DPI values in
excess of 72 (which is the case for most systems running), pt is a more
granular adjustment than px. IOW, by using px instead of pt for choosing
a default, a user has a greater selection of choices, particularly when
DPI gets really high. So, more than 4 years ago the Mozilla project
switched to using px instead of pt for choosing the default, using the
doze 12pt value of 16px as its default.
Linux systems are largely used by those astute enough to do extensive
customizing, including setting an accurate DPI. Since pt sizes depend on
DPI, fonts on Linux are likely to be initially smaller than on default
Mac or doze, unless the browser defaults are also changed, in which case
they could be just about anything.
So, assuming system default DPI and no system font size or browser font
size customization by the user have occurred, the following are the
values for the most widely known current and recent browser versions:
IE most 12pt (16px)
IE high resolution laptops 12pt (20px)
Opera most 12pt (16px)
Opera high resolution laptops 12pt (20px)
Konqueror 11pt (~15px @ 96 DPI)
Tier 1 Gecko (Firefox, Mozilla, Netscape 6+, SeaMonkey) 16px
Other Gecko (a few, there are others):
Camino might be 14px
Epiphany 11pt/~14px
K-Meleon 16px
Safari (I think same as tier 1 gecko at 16px, possibly 12pt/16px)
Assuming anything about how many users change their defaults misses the
point. The ones who change it invariably are the ones who want or need
it changed, and are those most hurt when the defaults are not respected.
Plus, we have no idea how many of those who don't change it find it
perfectly adequate as they got it, rather than those who have no idea it
is adjustable AND would change it if they knew.
Using 16px default as a starting point is the best point to test from,
but it is only one of many data points needed to ensure that it remains
reasonably accessible regardless what default the user is using, or what
zoom level, or what his minimum font size. If you can zoom down 3 steps
and up 300% without text overlapping or hiding, then you're going to
have a page accessible to virtually everyone with functional eyes.
Don't forget too, that simply zooming or upping the default won't
necessarily be a fair test. The idea here is to keep the relationship
between font size and viewport width within a reasonably narrow range.
Someone running a seriously high default size is probably running a high
resolution, not 800x600. Without running at high resolution, you won't
be able to keep the same perspectives as at 16px in a maximized 800x600
browser, or 1024x768 at less than full screen, because the narrower
width will constrain disproportionately. IOW, you're basically shooting
for having the sizing work out to relatively equal line lengths for your
paragraphs even though text size varies, because window sizes tend to be
bigger when text sizes are bigger. Using Opera's full page zoom can give
you the general idea even if you aren't running high resolution, as it
will just create a horizontal scroll, but it isn't a fair test, zooming
images as well.
--
"Blessed is the nation whose God is the Lord." Psalm 33:12 NIV
Team OS/2 ** Reg. Linux User #211409
Felix Miata *** http://mrmazda.no-ip.com/auth/
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