Originally posted by Snakeisthestuff I tested both lenses extensively in the store myself.
I found that even though te sharpness is comparable the 28-105 has a lot more distortion at 55mm and more ugly "bokeh balls".
On the other hand you need to learn how to handle the 55 since it can produce funky bokeh i.e. F1.4.
Also the AWR of the 55 is of course superior (after having fungus in my 18-55 WR, I think that might matter).
I use Lightroom and its lens profiles, so distortion (etc) tends not to be a problem.
I've just tried switching
off the lens profile correction for the DA* 55mm at
f/1.4, and that turned it from a lens with dreadful image quality (on the K-1) to a lens with dreadful image quality and bad distortion and bad vignetting (
without the hood)!
I've had the DA* 55mm since January 2012, and it has never been a lens that I could take seriously at f/1.4, even on K-5-series and K-3-series APS-C cameras. (Perhaps mine is a bad one, but I've seen criticism about it wide open elsewhere).
I recently did a walk around a stately home with the DA* 55mm on my K-1 at
f/2.8, and was disappointed with left and right edge sharpness for photos of the building itself and its grounds, and the corners were a bit worse.
I haven't compared the bokeh. And I'm not very worried about the difference between WR and AW, because one difference is that in bad weather I try not to change lenses, and so I prefer zooms to primes.