The NPL Centrax - A New Lens For Photogrammetry

A monocentric axicon camera has been designed for use in high precision photogrammetry with steel ball or point source targets. An example has been constructed and assembled successfully in a prototype camera body. The axicon patterns which it records remain sharp and symmetrical for all object distances from 300 mm to infinity, over an angular field 40o in diameter. Theoretically the distortion of this camera should be zero, and first measurements indicate that it does not exceed 100 nm across 50 mm plate-width.