San Marco Square

The tourists arrive at 10 o?clock, by which time the pigeons have already assembled for their late breakfast, and the artists have gone home. However, the main problem in architectural photography is to get the verticals parallel in the image (OK, most of the buildings in Venice are a bit skew, so you might put it down to the grappa instead).

If you are shooting on silver you can cure the problem with a view camera or a slide camera, but with a camera with a fixed lens, you would have to do the correction in the dark room.

With a digital camera you either need to keep the camera dead level, and crop afterwards, or use image processing software afterwards. In the image you have posted, Photoshop is no good. You will get a much better result with Pano Tools PtGui, which was done in my attachment. Unfortunately, you have a huge amount of barrel distortion on you lens, which not even PtGui can correct. The only way you can probably do it is to correct the camera with DxO software, then use PtGui. See:

http://www.dxo.com/en/corporate/home/default.php

You now have a good excuse to go back to Venice (well, I tell that to my wife).