I have found some full resolution JPGs of the 28-45, but not RAW yet, and they looks incredibly crisp, inclusive at the corners, and on the 25 the corners do not look as crisp as on the zoom, I'm going to repeat some shots with the 25 on a tripod this time just to be sure the lack of crispness I see are not product of a shaky camera.
---------- Post added 11-09-14 at 09:30 PM ----------
Originally posted by Thomasbrowphoto Im also interested to see the 28-45 in a wide open situation like astro. I have the DA 25mm and is pretty good for astro, However I always seem to get slight start trails what ever the exposure duration from 10sec to 30sec. I have a very solid tripod so that illiminates camera movement. So far I'm very impressed with my 25mm and that extra few mm is important for me to have.
If you want to eliminate trailing, get something like a Merlin arm, so the camera follow the stars, although then you will have blur on anything on Earth :-).