2 A B C D E F G H I K L M N O P R S T U V W
S- Sa Sc Se Sh Si Sn St

stereographic

stereographic lenses are a class of fisheye lenses

sterographic lenses are also called “ conform“or “ winkeltreu“
stereographic lenses use image mapping functions of type
r = 2 f tan \frac{\theta}{2}

maintains angles

[table caption=”stereographic angles” width=”500″ colwidth=”50|50|50|50″ colalign=”center|center|center|center”]
weak,medium,strong,max
94,131,180,<360
[/table]

Example of a Stereographic image :
stereographic

see Fisheye Types