All smartphone and tablet browsers allow users to use the pinch-zoom gesture to zoom in on web pages. This allows web pages designed for PCs to be fully usable on small-screen devices since this gesture is extremely intuitive and fluid. Due to the ubiquity and simplicity of this gesture, it is almost as second-nature as scrolling.
However, websites differ in their usability with pinch-zoom. News sites which list articles in blocks (i.e. The New York Times) are very suited to pinch-zoom. You can zoom in to magnify the area that I put in a red box. When zoomed in the number of letters per row is about 30, which means that the letters will be quite big and easily legible, even on a smartphone screen.
On the other hand, web sites that simply use a list for headlines are not suited to pinch-zoom. (i.e. MacSurfer’s Headline News). Zooming in on the headlines would result in the red box. However even with zooming, the number of letters per row is more than 80. The fonts are too small to read easily on a smartphone, although tablets will be OK.
For pinch-zoom to work well on smartphones, less than 50 letters per line is optimal.
In Apple’s mail app on the iPhone, a font size that give 40 letters per line is used for simple text messages. In Mobile Safari, the default font size is set to 16px which allows for about 50 letters per line when the
viewport tag is set to
device-width. The minimum font-size that one can read comfortably differs between individuals, we can safely assume that a size that gives 40-50 letters per line on an iPhone will be comfortably legible for most users.
Therefore for pinch-zoom to work well on smartphones, the number of letters per line in the zoomed box should be less than 50. If we cannot satisfy this, then pinch-zoom will not provide a good enough experience.
The MBSJ2012 website did not use a multicolumn layout, nor did it use a newspaper-like layout. Hence, there were very few pages where pinch-zoom would make sense.
However, it might be interesting to investigate designs with multiple columns or a newspaper-like layout. This could be especially helpful when we want to highlight exhibition activities. These might need pinch-zoom.