Abstract: A monocular inspection system (10) having a substantial eye relief (62), a large exit pupil, and a line of sight viewing of an object under observation (14). The inspection system (10) includes an objective lens assembly (20) which forms an image of the object (14) and which has an axis coincident with an optical path (66). A prism (16) redirects the optical path (66) to coincide with a viewing axis (64) such that the image is formed in a focal plane intersected by the viewing axis (64). A monocle assembly (40) having an axis coincident with the viewing axis (64) forms an exit pupil for the image.

Abstract: Optical systems with very long eye relief and large working distances (10) and (110) with four lenses (12), (14), (16), (18) and (20) and three lenses (112), (114) and (116), respectively, have lens surfaces shaped to focus upon an object such that a high resolution image is formed at infinity substantially over the entire field of view. High resolution and low distortion are substantially maintained independent of the user's eye location.

Abstract: A stereomicroscopic inspection system having low eyestrain features is disclosed. The system (10) includes an objective lens assembly (12) for forming an image of a viewed object (22). A prism mechanism (14) is positioned adjacent to the objective lens assembly (12) for orienting the image along a heads-up axis. A telephoto objective assembly (16) is positioned adjacent to the prism mechanism (16) for focusing the image transmitted through the prism mechanism (14). A reticle (18) is positioned adjacent to the telephoto objective assembly, and the image is focused (16) onto the reticle (18). An assembly (20) is positioned adjacent to the reticle (18) for enabling heads-up viewing of the object by the viewer, (22) said system projecting a virtual image at a predetermined distance from the viewer. This distance may be substantially equal to the eye's natural focusing distance to minimize eyestrain.

Abstract: A six element optical magnifying system (10) is disclosed. The primary lens (12), secondary lens (14), tertiary lens (16), quaternary lens (18), quinary lens (20), and sextiary lens (22) form an optical system (10), having surfaces shaped to focus upon an object such that a high resolution image is formed at infinity at 10.times. magnification substantially over the entire field of view.

Abstract: A four element optical magnifying system (10) is disclosed. The primary lens (12), secondary lens (14), tertiary lens (16), and quaternary lens (18) form an optical system (10) have surfaces shaped to focus upon an object such that a high resolution image is formed at infinity at 4.times. magnification substantially over the entire field of view.

Abstract: An apparatus (10) for measuring the magnification power of a magnifying aid (14) is disclosed. The apparatus (10) includes an optical system (12) having an objective lens (34) focused at infinity on a reticle. The reticle (20) is positioned in the line of sight of the optical system (12). The reticle (20) is precalibrated such that the magnification power of a magnifying aid (14) may be determined. Also, disclosed is a method of calibrating the optical system (12) and a method of measuring the magnification power of a magnifying aid (14).