Instructions to Define the Nodal Point Roundshot Super 220 VR Software Release 4.0 and higher © by Seitz Phototechnik AG, Hauptstr. 14, 8512 Lustdorf, Switzerland, Phone: +41 52 376 3353, Fax: +41 52 376 3305,
[email protected], www.roundshot.ch Technical changes reserved, Released: 1.2005 Page 0 1. Introduction 1.1 What is a nodal point? The term „nodal point“ defines the optical centres of a lens where the incoming light is bundled in the optical axis. First nodal point (H’) Second nodal point (H) The first (front) nodal point is the The second (rear) nodal point is the position on the optical axis of a position on the optical axis of a lens lens where the entering ray where the departing ray crosses the crosses the optical axis. optical axis. Film plane Focal length Thedistance fromthesecond (in mm) nodal point to the focal point (film plane) is the focal length. 1.2 What is the significance of the nodal point for panoramic photography? For rotational panoramic photography of up to 360° the camera head with the lens rotates around a vertical axis. For optimum sharpness the nodal point needs to be exactly at the centre of this axis. If the nodal point is not situated exactly at the centre of the rotation axis, a so-called parallax effect occurs. When rotating the camera the distances between vertical lines change and sharpness as well as depth of field decreases. Good nodal point: Bad nodal point (parallax effect): © by Seitz Phototechnik AG, Hauptstr. 14, 8512 Lustdorf, Switzerland, Phone: +41 52 376 3353, Fax: +41 52 376 3305,
[email protected], www.roundshot.ch Technical changes reserved, Released: 1.2005 Page 1 2.