Matrox Iris GT MIL, Инструкция по установке и техническое руководство, Страница: 104 / 256

104 Appendix C: Selecting a lens
Introduction
This appendix includes information on lens selection, an important consideration
when building your application.
The primary consideration during lens selection is that the focal length of the
selected lens meets your application’s requirements.
The focal length is the distance between the principal plane and the point where
parallel light rays, bent at the principal plane, intersect the optical axis.
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Note that each lens is designed for a specific focal length; a zoom lens is designed
for variable focal lengths.
Focal length
Focal point
Image plane
Principal plane (H2)
Parallel light rays
Parallel light rays
Optical axis