I currently have two wide angle zooms for my α100: a Sigma 24-70, f2.8 EX DG and a Tokina AT-X PRO 20-35 f2.8, both of which provide fine images. Can anyone suggest a wider angle zoom of similar quality? I've looked at Tokina, Sigma and Sony for options and current offerings seem to be all slower and/or unavailable in the Sony (aka Minolta) mount. Any suggestions would be welcome...