DA 16-45mm Edge Sharpness

Now I know I have asked about getting a replacement for this lens, but recently the monies reserved for a replacement went to to studio flash units that I needed more.
So, now I have a little time to consider a replacement for this lens.
Why? well today I took some shots for work with the aformentioned studio units etc, and everything seemed fine on the back of the camera. However upon putting them on the computer and zooming in the people at the edges are soft to say the least. I was shooting at F11 1/125sec at ISO 200 at the time, so High ISO has nothing to with it. At the centre? no problem at all. I think that partially the DA16-45 has reached its limit of resolution on the K-5, certainly at the edges.

So, two questions.

1. Has anyone else seeing issues with the 16-45 with softness at the edges, especially on the K-5
2. What you would you consider to be better for edge to edge sharpness on a wide-short tele zoom? Obviously the usual suspects will appear. The DA* 16-50, The Tamron 17-50 and the Sigma 17-50 EX.

Advices please

I've only used the DA* 16-50 out those and it may not have sharp corners at f2.8 but stopped down to f5.6-8 it is a lot better. Centre sharpness is very good all the time. Have to be careful with moire on the K10D.

I think the 16-45 is more evenly sharp across the frame though.

Edge sharpness varies with focal length and some zooms may be
better than others at certain FL's. Apart from below 20mm
the Mk II kit lens isn't too bad at the corners and f/8.

Without an example is isn't possible to make a judgement - we don't know for example how big in the frame the people at the edges are, or how much you have zoomed in.

Can you post the image?

See this link thread for some corner shots from the Mk II Kit Lens.

I think the OP is referring to using the 16-45 on a K5, not a K10.

Dave

I've said this before. I've always been disappointed with my 16-45, partly because I have a remarkably good 18-55. However, I too sometimes get strangely soft edges but its inconsistent but I'm sure its around f11 (without checking). I use a K20D.

Most of the time when shooting professionally I use M or AV but for casual personal work I use P(MTF) where the camera chooses the aperture where the lens is proven to work best and for this lens its F4.5 which seems to go against popular wisdom.