Why rotate around the nodal point?

To avoid parallax error. Only then do foreground and background not shift against each other, and the panorama can be assembled cleanly.

Panorama Stitching

Category: Processing

A form of stitching joining offset frames into a wide panorama. The normal case is a wide section — full 360-degree surround views are a special case, not the rule.

Panorama stitching applies stitching to an extended angle of view. Several horizontally or vertically offset frames are joined into an image with a wide field of view.

The normal case is a wide, partial panorama — a full 360-degree surround view is a special case, not the rule. To keep straight lines straight and avoid ghosting, the camera is ideally rotated around the nodal point of the lens; depending on the angle of view, cylindrical or spherical projections are used.

When many rows are combined, a panorama simultaneously becomes a high-resolution gigapixel image.