I finally got a wide angle lens that let me match the FOV (Field Of View) of the Kinect, a Canon EF-S 10-22mm f/3.5-4.5 USM, borowed from the Fine Arts College facilities where I work, in the Universitat Politécnica de Valencia.
I made a small application as a proof of concept towards an automated Kinect - DSLR calibration process, and also for a possible further automated recording-download system controlling remotelly the DSLR via USB.