Originally posted by Des What he says about the 21 is broadly applicable to the 20-40.
If that is true, if the DA 20-40 performs pretty much like the DA 21 (particularly at apertures generally used in landscape photography), then I'd expect it to be slightly better than the DA 16-85. I'm not talking here about "sharpness," which is probably a wash (or perhaps better toward the edges and corners with the DA 16-85). What the limiteds give you is slightly richer color, a bit more contrast and clarity, and perhaps slightly more realistic rendering of detail (i.e., the "smooth but precise" rendering). But the DA 16-85, especially in the 20 to 40 range, really is quite good in those respects as well, so these differences are subtle, and won't necessarily be obvious. I bought both the DA 21 and DA 35 Ltds after I had the DA 16-85, and I did so to get little extra image quality, which is all they provide. They are also a little easier to work with because of their smaller size, but the downside is you lose focal range variety. The DA 20-40 gives you more versatility, but not as much, obviously, as the DA 16-85. If you already have one of the wide angle zooms, along with the DA 55-300 PLM, you can get away with the DA 20-40 as your standard zoom for landscapes. If however you're looking for a one lens solution, the DA 16-85 is the obvious choice.
Here are a few images with the DA 16-85: