question.What is the difference between a fixed 10.5mm nikkor fisheye and a 10mm focal length on a 10-20mm sigma?what is the difference between a fisheye and a regular zoom lens at the same focal length?
The fisheye has an optical nerve attached to it.A zoom lens goes on a camera.
.5mm
1. Half a millimeter2. In a rectilinear wideangle lens like the 10-20, the optics are corrected so that straight lines look straight in the picture. In a fisheye, it's not--a straight line looks all curved.