28 relations: Airy disk, Aperture, Autofocus, Bokeh, Cardinal point (optics), Cassegrain reflector, Circle of confusion, Collimated light, Curved mirror, Defocus aberration, Depth of field, Depth of focus, Diffraction, Ellipse, Far point, Fixed-focus lens, Focal length, Focus (geometry), Focus stacking, Geometrical optics, Hyperbola, Lens (optics), Manual focus, Mirror, Optical aberration, Parabola, Ray (optics), Sphere.
In optics, the Airy disk (or Airy disc) and Airy pattern are descriptions of the best focused spot of light that a perfect lens with a circular aperture can make, limited by the diffraction of light.
In optics, an aperture is a hole or an opening through which light travels.
An autofocus (or AF) optical system uses a sensor, a control system and a motor to focus on an automatically or manually selected point or area.
In photography, bokeh (— also sometimes pronounced as) is the aesthetic quality of the blur produced in the out-of-focus parts of an image produced by a lens.
In Gaussian optics, the cardinal points consist of three pairs of points located on the optical axis of a rotationally symmetric, focal, optical system.
The Cassegrain reflector is a combination of a primary concave mirror and a secondary convex mirror, often used in optical telescopes and radio antennas.
Christmas is an annual festival commemorating the birth of Jesus Christ,Martindale, Cyril Charles.
The Christmas season, also called the festive season, or the holiday season (mainly in the U.S. and Canada; often simply called the holidays),, is an annually recurring period recognized in many Western and Western-influenced countries that is generally considered to run from late November to early January.
Christmas Eve is the evening or entire day before Christmas Day, the festival commemorating the birth of Jesus.
Christmas traditions vary from country to country.
In optics, a circle of confusion is an optical spot caused by a cone of light rays from a lens not coming to a perfect focus when imaging a point source.
Collimated light is light whose rays are parallel, and therefore will spread minimally as it propagates.
A curved mirror is a mirror with a curved reflecting surface.
In optics, defocus is the aberration in which an image is simply out of focus.
In optics, particularly as it relates to film and photography, the optical phenomenon known as depth of field (DOF), is the distance about the Plane of Focus (POF) where objects appear acceptably sharp in an image.
Depth of focus is a lens optics concept that measures the tolerance of placement of the image plane (the film plane in a camera) in relation to the lens.
--> Diffraction refers to various phenomena that occur when a wave encounters an obstacle or a slit.
In mathematics, an ellipse is a curve in a plane surrounding two focal points such that the sum of the distances to the two focal points is constant for every point on the curve.
In visual perception, the far point is the point at which an object must be placed along the optical axis of the eye for its image to be focused on the retina when the eye is not accommodating.
A photographic lens for which the focus is not adjustable is called a fixed-focus lens or sometimes focus-free.
The focal length of an optical system is a measure of how strongly the system converges or diverges light.
In geometry, focuses or foci, singular focus, are special points with reference to which any of a variety of curves is constructed.
Focus stacking (also known as focal plane merging and z-stacking or focus blending) is a digital image processing technique which combines multiple images taken at different focus distances to give a resulting image with a greater depth of field (DOF) than any of the individual source images.
Geometrical optics, or ray optics, describes light propagation in terms of rays.
In mathematics, a hyperbola (plural hyperbolas or hyperbolae) is a type of smooth curve lying in a plane, defined by its geometric properties or by equations for which it is the solution set.
A lens is a transmissive optical device that focuses or disperses a light beam by means of refraction.
In the field of photography, a manual focus camera is one in which the user has to adjust the focus of the lens by hand.
A mirror is an object that reflects light in such a way that, for incident light in some range of wavelengths, the reflected light preserves many or most of the detailed physical characteristics of the original light, called specular reflection.
New Year is the time or day at which a new calendar year begins and the calendar's year count increments by one.
New Year's Day, also called simply New Year's or New Year, is observed on January 1, the first day of the year on the modern Gregorian calendar as well as the Julian calendar.
In the Gregorian calendar, New Year's Eve (also known as Old Year's Day or Saint Sylvester's Day in many countries), the last day of the year, is on 31 December which is the seventh day of Christmastide.
Aberration in optics refers to a defect in a lens such that light is not focused to a point, but is spread out over some region of space, and hence an image formed by a lens with aberration is blurred or distorted, with the nature of the distortion depending on the type of aberration.
In mathematics, a parabola is a plane curve which is mirror-symmetrical and is approximately U-shaped.
In optics a ray is an idealized model of light, obtained by choosing a line that is perpendicular to the wavefronts of the actual light, and that points in the direction of energy flow.
A sphere (from Greek σφαῖρα — sphaira, "globe, ball") is a perfectly round geometrical object in three-dimensional space that is the surface of a completely round ball (viz., analogous to the circular objects in two dimensions, where a "circle" circumscribes its "disk").
2018 has been designated as the third International Year of the Reef by the International Coral Reef Initiative.
2019 (MMXIX) will be a common year starting on Tuesday of the Gregorian calendar, the 2019th year of the Common Era (CE) and Anno Domini (AD) designations, the 19th year of the 3rd millennium, the 19th year of the 21st century, and the 10th and last year of the 2010s decade.