An optical axis is an imaginary line that passes through the geometrical center of an optical system such as a camera lens, microscope or telescopic sight...

An off-axis optical system is an optical system in which the optical axis of the aperture is not coincident with the mechanical center of the aperture...

consist of three pairs of points located on the optical axis of a rotationally symmetric, focal, optical system. These are the focal points, the principal...

Optical axis gratings (OAGs) are gratings of optical axis of a birefringent material. In OAGs, the birefringence of the material is constant, while the...

wavelength in an optical system. The second form of astigmatism occurs when the optical system is not symmetric about the optical axis. This may be by...

contains both the object point and the optical axis (meridional or tangential plane). Such rays do not cross the optical axis anywhere and are not parallel to...

electronic image stabilization can also compensate for rotation about the optical axis (roll). It is mainly used in high-end image-stabilized binoculars, still...

down along the bore axis. The distance between the bore axis and the sight axis (the optical axis of a sighting device), also known as the sight height...

any optical system, rays proceeding from an axis point O under an angle u1 will unite in the axis point O′1; and those under an angle u2 in the axis point...

light propagates in such materials (along a direction different from the optical axis), it splits into two different rays, known as ordinary and extraordinary...

Unlike a spherical mirror, a bundle of parallel rays parallel to the optical axis will be perfectly focused to a point (the mirror is free of spherical...

mirror to redirect the light through the lenses with a 90° angle to the optical axis, as in a periscope. The Kenworthy/Netman Snorkel Camera System, introduced...

(directions normal to the wavefronts) are at small angles θ relative to the optical axis of the system, such that the approximation sin θ ≈ θ remains valid. A...

(i.e., no spherical aberration) only at a lateral distance from the optical axis that equals the radius of the spherical surface divided by the index...

stop), that will be about parallel to the optical axis on the other side of the lens, to pass the optical system for any object point in the field of...

the rotation of the orientation of the plane of polarization about the optical axis of linearly polarized light as it travels through certain materials....

material), u {\textstyle u} is the on-axis (on the optical axis) object distance from the line perpendicular to the axis toward the refraction point on the...

magnification implies an inverted image. The image magnification along the optical axis direction M L {\displaystyle M_{L}} , called longitudinal magnification...

to all the optical elements in an instrument being on their designed optical axis. It also refers to the process of adjusting an optical instrument so...

optical system (such as a lens). A paraxial ray is a ray that makes a small angle (θ) to the optical axis of the system, and lies close to the axis throughout...

vertex (where the optical axis meets the mirror) will form an angle with the optical axis. The reflected ray has the same angle to the axis, but on the opposite...

In optics, a thin lens is a lens with a thickness (distance along the optical axis between the two surfaces of the lens) that is negligible compared to...

by forcing all frequencies to propagate at a 90° with respect to the optical axis of the crystal. These methods are called temperature tuning and quasi-phase-matching...

Rays that move closer to the optical axis as they propagate are said to be converging, while rays that move away from the axis are diverging. These imaginary...

the optical axis. Spherical lenses are adequate correction when a person has no astigmatism. To correct for astigmatism, the "cylinder" and "axis" components...

Yolo telescopes and optical monochromators. In these devices, the source and detectors of the light are not located on the optical axis of the mirror, so...

In an optical system, the entrance pupil is the optical image of the physical aperture stop, as 'seen' through the optical elements in front of the stop...

breakthroughs. In an optical vortex, light is twisted like a corkscrew around its axis of travel. Because of the twisting, the light waves at the axis itself cancel...

named for Joseph Petzval, describes the optical aberration in which a flat object normal to the optical axis (or a non-flat object past the hyperfocal...

cylinders whose sides are thin walls. Each cylinder lines up parallel to the optical axis into which electrons enter. There are small gaps put between the cylinders...