- From: Al Gilman <asgilman@iamdigex.net>
- Date: Thu, 11 Jul 2002 21:44:07 -0400
- To: "Ian B. Jacobs" <ij@w3.org>, w3c-wai-ua@w3.org
At 03:32 PM 2002-07-11, Ian B. Jacobs wrote: >------------------ >On checkpoint 4.1 >------------------ > >IJ: What about new wording? > > 1. Allow global configuration of the scale of visually rendered > text. Preserve text size differences when the user changes the > scale. > >IJ: Suggest: "Text rendered at different sizes should scale >proportionally." > >HB: What about rounding errors? > >Action IJ: > > 1. Change second sentence in bullet one to > "Text rendered at different sizes should scale proportionally." AG: I object to this change. I was quite careful in the earlier language _not_ to suggest proportional scaling. It is not a good idea. The order of the differences should be preserved; the smallest should wind up smallest etc. But the ratios of the sizes should be compressed in the enlargement. You have to pack the same number of different sizes into a smaller dynamic range, that is to say the ratio between the largest feasible font size to the smallest feasible font size. People with low vision have less available dynamic range with regard to font size than people with 20:20 vision. The nose reader at the limit of who can use the screen at all has a short distance from them to the screen and the amount of text that they can see is limited by their field of vision, not the size of the physical display. By the time one gets to the edges of the physical display screen, it is beyond where they can focus. So one is fighting the reduced dynamic range between where the details in the glyphs are too fine for them to resolve on the small font end and where the amount of text that fits in their field of vision is too few characters to support reading. This is the extreme case just before the screen gets useless, but this is where to think about. So one want to compress the range of type sizes, into something like new sizes of 18, 20, 22, 24, 28 from old sizes of 6, 8, 11, 14, 20. You don't want to force the top size to 60 just to make the stuff that was in size 6 (before enlargement) be size 18 to be legible. Please reconsider this change. Al
Received on Thursday, 11 July 2002 21:44:26 UTC