Field Testing the Zeiss Touit 12mm f/2.8 Lens

Introduction
When the Dutch representative of the Zeiss lenses asked me whether I am interested in testing the Zeiss Touit 12mm lens, I immediately agreed. Zeiss is a legendary name in lens design and I was interested to see the first models of the new line of autofocus lenses for the Fujifilm X series and Sony Alpha NEX mirrorless system cameras.
Most of the reviews that I have seen so far focused on the general characteristics of the lens, such as build quality, resolution, distortion, etc. These characteristics are of course very important to consider before one decides to buy a lens. However, what I was missing in the reports was the discussions on specific use-cases of ultra wide angle lenses, and how this Zeiss lens performs for these use-cases (for example, architecture, nighttime cityscape and landscape photography).
Hence, the goal of this article is to give some impressions about the performance and handling of this lens from the point of view of these uses-cases. I will, o...