DOF for landscapes

The 14-24 Nikon is the one I decided on, because the close-in lower left and right foreground, which populates 90% of my superwide pics is much sharper in the corners at f8 than any other lens I could find, while maintaining good focus at the far points.  Nikon obviously designed it that way and it works beautifully.  You simply focus on the corner or a bit further out with live view. If the corners are at infinity focus, such as from the edge of a cliff or on the umpteenth floor of a building, then the Samyang and the Zeiss 15 maintain their corner sharpness much better.  You pays your money and you takes your whacks!

This website explains it much better than I can:

http://3dkraft.de/index.php?option=com_content&view=article&id=127:uwa-comparison&catid=40:camerasandlenses&Itemid=2

As to longer FLs, the 50mm Nikons do a really good job at f8, pretty much corner to corner, as does the 35D.  What can I say, I'm happy as hell :^)