Originally posted by luftfluss One also pays for sharpness, and the HD 20-40 doesn't appear to offer enough of that for a $900 lens, according to most reports I've read.
A good copy is very sharp on center wide open and very sharp on border too at f/5.6. This lens is a landscape, trips and hiking lens where the idea is to have a very small lens that provide very high quality, sharpness, nice colors in a very small high quality and WR package. There simply no competitive offering.
If you prefer, it replace your DA21 + DA40 for arround the same price and with the ability to zoom. It is sure through that one should not use it for portraiture, but one would add the DA70, problem fixed.