The Reasons Why Fisheye Lenses Are Used

Action cameras are being used in high-altitude balloons, rocket launches, and the ISS because they have some advantages compared to other cameras. And most action cameras are equipped with a fisheye lens.

Flat-Earthers allege that there is an evil intention behind every use of fisheye lenses, especially in space and high-altitude usages. They are wrong. The use of fisheye lenses is not unreasonable. And if a rectilinear result is desired, it is trivial to convert any fisheye footage to a rectilinear one.

An action camera like a GoPro® has various advantages:

  • Wide field-of-view. A rectilinear SLR camera with a wide-angle lens does not have as much field-of-view.
  • Fixed focus and wide depth-of-field. Very close objects, far away objects and everything in between are in focus. No focusing is needed.
  • Small and lightweight. A GoPro weighs a mere 117g (4oz). Far smaller and lighter than any SLR cameras.
  • Cheap and disposable. Many vendors are producing action cameras. It is cheap and easy to replace one with another.
  • Weatherproof, waterproof and durable.
  • Plenty of standardized mounting options that work across products from the different vendors.
  • Wireless control. Videos can be transmitted over the wireless connection.

If a rectilinear video output is desired, then it is trivial to convert the fisheye video output from any action camera to a rectilinear one.

The allegations from flat-Earthers are unfounded. The use of fisheye lenses are not unreasonable, and there is no evil intention behind such use of a fisheye lens.