Various types of fisheye lenses are available.

Here a short overview:

Type | gnomonic | stereographic | F-Theta | equal area | orthographic |
---|---|---|---|---|---|

lens class | wide angle | Fisheye | Fisheye | Fisheye | Fisheye |

mapping function | |||||

normalized mapping function | |||||

meridional scaling | |||||

sagittal scaling | |||||

effective scaling | |||||

N from | 2 | 1 | 0 | -1 | |

Balance Deform. vs. Scaling | 0 | -2 | 2 | ||

Curvature | 0 | -1 | |||

Deformation | |||||

maintains | - | angles | angular distances | areas | planar illuminance |

AOV | <180° | <360° | >= 360° | 360° | 180° |

54° | 94° | 115° | 94° | 66° | |

75° | 131° | 159° | 131° | 90° | |

102° | 180° | 217° | 180° | 120° |

Source of the various angles and formulae: wikipedia

Here the angle is measured in Radians !

**
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**equal area**lenses are also called “

**equisolid angle”**or

**“flächentreu”**

**F-Theta**lenses are also called “

**equidistant**“, “

**linear scaled**“, “

**äquidistant**” or “

**angular**”

**sterographic**lenses are also called “

**conform**“or “

**winkeltreu**”

**orthographic**lenses are also called”

**hemispherical**“or “

**orthographisch**“

For details see:

equal area

F-Theta

gnomonic

orthographic

stereographic