I have created the Ultrawide Photography Group. If you are interested, please sign up.
Here is the basic idea: it is a group to show and discuss ultrawide photography. Lenses: 16mm or wider on crop sensors, 24mm or wider on full-size sensors and 35mm film cameras. Equivalent focal lengths for larger format gear.
No fisheye photographs or lenses, stitched images or software/in-camera panoramas please.