Hauptstrahl(the ray from any oblique object point passing through the centres of the iris and pupils of a lens, the ray midway between the extreme upper and lower rim rays, or the ray through the centre of the aperture)
Hauptstrahl(the ray from any oblique object point passing through the centres of the iris and pupils of a lens, the ray midway between the extreme upper and lower rim rays, or the ray through the centre of the aperture)
Hauptstrahl(the ray from any oblique object point passing through the centres of the iris and pupils of a lens, the ray midway between the extreme upper and lower rim rays, or the ray through the centre of the aperture)
Durchrechnung(this means determining the paths of various rays as they pass through the elements of an optical system, with the aim of bringing all the rays from an object point as close as possible to a point intersection in the image plane)