Originally posted by kh1234567890 Corner-to-corner span is about the same, if you look at the shots carefully, but because of the different mapping the Samyang effectively captures a wider angle at the frame width and height.
Yes, the mapping of the Pentax distorts the edges of the frame more, so it pushes details out. This is why I picked the Samyang after reading about the stereographic projection in reviews. The Pentax one seems to be of equisolid type. With the Samyang, if you have a person at the edge of the frame, they still look human, but with the Pentax (as well as with most other fisheye designs), the distortion goes wild at the edges.