They are great lenses, Jon. If you keep the horizon in the middle of the shot you can use it as a UWA ( well, sort off)
Samyang 7.5mm fisheye by damianmkv, on Flickr
11477336673_dc664e1bdb_c by Dave in Wales, on Flickr
11477216464_de6b6c81bb_c by Dave in Wales, on Flickr
Hall D:F LR6 by Dave in Wales, on Flickr