I've been using a 17-85 IS for about a year now and have developed a slightly more discerning eye with regards to sharpness in my landscape photos. I can never seem to get the level of sharpness I desire from the 17-85. I'm looking to upgrade.
Can anyone offer suggestions for a nice walkaround zoom lens that takes (significantly) sharper landscape shots than the 17-85? I'd also like one that's AT LEAST on par, if not better than the 17-85 in all other respects. I've been looking specifically at the following, but other suggestions are more than welcome:
Canon EF 24-105mm f/4 L IS
Canon EF-S 17-55mm f/2.8 IS
Canon EF 17-40mm f/4L
Canon EF 24-70mm f/2.8L
Tamron AF 17-50mm F/2.8
Tamron AF 28-75mm f/2.8
Sigma 24-70mm f/2.8
At the moment, I'm leaning toward one of the one of the first three on the list. The 17-85 has been my walkaround for quite a while now and I need something that's as versatile, hence the necessity for the zoom. Any advice for me?
Thanks in advance!
PS: A majority of my landscapes end up being stitched panoramas, if that affects your advice at all.