The current maximum zoom level (I think it's "5" from the url) seems too low for some of the pictures. For example, this shot [1] from the picture "Nick Field" is zoomed to the maximum level but looks like it could zoom quite a bit more while still having a useful level of resolution and quality.
It's capped at 5 I think. Zoom level five corresponds to a width of 8,192 pixels. Zoom level 6 would be 16,384 pixels. And the Nick Field picture is only 10,768 pixels wide.
[1] http://hugepic.io/35f881f45#5.00/80.636/-135.923