XPan is the only 35 mm format flat plane pano camera. Swing lens cameras all suffer from heavy distortions, e.g straight lines bulge heavily towards the photographer and sometimes they do not look good. Using 6x7, 6x8 and 6x9 and trimmed to pano would mean: firstly 120 films are required, secondly, it loses the perspective from a photographer's viewpoint at the time of shooting.