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Index F-number

The f-number of an optical system (such as a camera lens) is the ratio of the system's focal length to the diameter of the entrance pupil. [1]

78 relations: Absolute value, Acutance, Addison-Wesley, American National Standards Institute, Angle of view, Aperture, APEX system, Atropine, Ƒ, Bokeh, Camera lens, Carl Zeiss, Charge-coupled device, Circle of confusion, Cycloplegia, Depth of field, Diaphragm (optics), Diffraction, Dimensionless quantity, Entrance pupil, Ernst Abbe, Exponentiation, Exposure (photography), Exposure value, Eyepiece, Film format, Film speed, Focal length, Focal Press, Geometric progression, Glaucoma, Group f/64, Human eye, Illuminance, Integer, John Henry Dallmeyer, Kodak, Large Synoptic Survey Telescope, Lens (optics), Lens speed, Light meter, Luminance, Macro photography, Magnification, Minolta, Moritz von Rohr, Nature photography, Numerical aperture, Objective (optics), Optical aberration, ..., Optical lens design, Optical telescope, Optics, Phenylephrine, Photographic lens design, Photography, Photojournalism, Pinhole camera, Poison, Portrait photography, Preferred number, Pupil magnification, Ratio, Reciprocity (photography), Rodenstock Imagon, Royal Photographic Society, Shutter speed, Siegfried Czapski, Smooth Trans Focus, Sony, Southern Astrophysical Research Telescope, Square root of 2, Sunny 16 rule, Tessar, Thomas Rudolphus Dallmeyer, Transmittance, Tropicamide, Vignetting. Expand index (28 more) »

Absolute value

In mathematics, the absolute value or modulus of a real number is the non-negative value of without regard to its sign.

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In photography, the term "acutance" describes a subjective perception of sharpness that is related to the edge contrast of an image.

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Addison-Wesley is a publisher of textbooks and computer literature.

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American National Standards Institute

The American National Standards Institute (ANSI) is a private non-profit organization that oversees the development of voluntary consensus standards for products, services, processes, systems, and personnel in the United States.

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Angle of view

In photography, angle of view (AOV) describes the angular extent of a given scene that is imaged by a camera.

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In optics, an aperture is a hole or an opening through which light travels.

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APEX system

APEX stands for Additive system of Photographic EXposure, which was proposed in the 1960 ASA standard for monochrome film speed, ASA PH2.5-1960, as a means of simplifying exposure computation.

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Atropine is a medication to treat certain types of nerve agent and pesticide poisonings as well as some types of slow heart rate and to decrease saliva production during surgery.

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The letter F with hook (majuscule Ƒ, minuscule: ƒ) is a letter of the Latin script, based on the italic form of f; or on its regular form with a descender hook added.

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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.

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Camera lens

A camera lens (also known as photographic lens or photographic objective) is an optical lens or assembly of lenses used in conjunction with a camera body and mechanism to make images of objects either on photographic film or on other media capable of storing an image chemically or electronically.

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Carl Zeiss

Carl Zeiss (11 September 1816 – 3 December 1888) was a German scientific instrument maker, optician and businessman who founded the workshop of Carl Zeiss in 1846 which is still in business today as Carl Zeiss AG.

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Charge-coupled device

A charge-coupled device (CCD) is a device for the movement of electrical charge, usually from within the device to an area where the charge can be manipulated, for example conversion into a digital value.

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Circle of confusion

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.

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Cycloplegia is paralysis of the ciliary muscle of the eye, resulting in a loss of accommodation.

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Depth of field

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.

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Diaphragm (optics)

In optics, a diaphragm is a thin opaque structure with an opening (aperture) at its center.

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--> Diffraction refers to various phenomena that occur when a wave encounters an obstacle or a slit.

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Dimensionless quantity

In dimensional analysis, a dimensionless quantity is a quantity to which no physical dimension is assigned.

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Entrance pupil

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

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Ernst Abbe

Ernst Karl Abbe HonFRMS (23 January 1840 – 14 January 1905) was a German physicist, optical scientist, entrepreneur, and social reformer.

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Exponentiation is a mathematical operation, written as, involving two numbers, the base and the exponent.

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Exposure (photography)

In photography, exposure is the amount of light per unit area (the image plane illuminance times the exposure time) reaching a photographic film or electronic image sensor, as determined by shutter speed, lens aperture and scene luminance.

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Exposure value

In photography, exposure value (EV) is a number that represents a combination of a camera's shutter speed and f-number, such that all combinations that yield the same exposure have the same EV (for any fixed scene luminance).

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An eyepiece, or ocular lens, is a type of lens that is attached to a variety of optical devices such as telescopes and microscopes.

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Film format

A film format is a technical definition of a set of standard characteristics regarding image capture on photographic film, for either stills or filmmaking.

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Film speed

Film speed is the measure of a photographic film's sensitivity to light, determined by sensitometry and measured on various numerical scales, the most recent being the ISO system.

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Focal length

The focal length of an optical system is a measure of how strongly the system converges or diverges light.

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Focal Press

Focal Press is a publisher of media technology books and it is an imprint of Taylor & Francis.

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Geometric progression

In mathematics, a geometric progression, also known as a geometric sequence, is a sequence of numbers where each term after the first is found by multiplying the previous one by a fixed, non-zero number called the common ratio.

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Glaucoma is a group of eye diseases which result in damage to the optic nerve and vision loss.

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Group f/64

Group f/64 was a group founded by seven 20th-century San Francisco photographers who shared a common photographic style characterized by sharp-focused on and carefully framed images seen through a particularly Western (U.S.) viewpoint.

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Human eye

The human eye is an organ which reacts to light and pressure.

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In photometry, illuminance is the total luminous flux incident on a surface, per unit area.

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An integer (from the Latin ''integer'' meaning "whole")Integer 's first literal meaning in Latin is "untouched", from in ("not") plus tangere ("to touch").

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John Henry Dallmeyer

John Henry Dallmeyer (6 September 183030 December 1883), Anglo-German optician, was born at Loxten, Westphalia, the son of a landowner.

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The Eastman Kodak Company (referred to simply as Kodak) is an American technology company that produces imaging products with its historic basis on photography.

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Large Synoptic Survey Telescope

The Large Synoptic Survey Telescope (LSST) is a wide-field survey reflecting telescope with an 8.4-meter primary mirror, currently under construction, that will photograph the entire available sky every few nights.

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Lens (optics)

A lens is a transmissive optical device that focuses or disperses a light beam by means of refraction.

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Lens speed

Lens speed refers to the maximum aperture diameter, or minimum f-number, of a photographic lens.

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Light meter

A light meter is a device used to measure the amount of light.

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Luminance is a photometric measure of the luminous intensity per unit area of light travelling in a given direction.

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Macro photography

Macro photography (or photomacrography or macrography, and sometimes macrophotography), is extreme close-up photography, usually of very small subjects and living organisms like insects, in which the size of the subject in the photograph is greater than life size (though macrophotography technically refers to the art of making very large photographs).

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Magnification is the process of enlarging the appearance, not physical size, of something.

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was a Japanese manufacturer of cameras, camera accessories, photocopiers, fax machines, and laser printers.

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Moritz von Rohr

Moritz von Rohr (4 April 1868 – 20 June 1940) was an optical scientist at Carl Zeiss in Jena, Germany.

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Nature photography

Nature photography is a wide range of photography taken outdoors and devoted to displaying natural elements such as landscapes, wildlife, plants, and close-ups of natural scenes and textures.

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Numerical aperture

In optics, the numerical aperture (NA) of an optical system is a dimensionless number that characterizes the range of angles over which the system can accept or emit light.

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Objective (optics)

In optical engineering, the objective is the optical element that gathers light from the object being observed and focuses the light rays to produce a real image.

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Optical aberration

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.

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Optical lens design

Optical lens design is the process of designing a lens to meet a set of performance requirements and constraints, including cost and manufacturing limitations.

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Optical telescope

An optical telescope is a telescope that gathers and focuses light, mainly from the visible part of the electromagnetic spectrum, to create a magnified image for direct view, or to make a photograph, or to collect data through electronic image sensors.

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Optics is the branch of physics which involves the behaviour and properties of light, including its interactions with matter and the construction of instruments that use or detect it.

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Phenylephrine is a selective α1-adrenergic receptor agonist of the phenethylamine class used primarily as a decongestant, as an agent to dilate the pupil, to increase blood pressure, and to relieve hemorrhoids.

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Photographic lens design

The design of photographic lenses for use in still or cine cameras is intended to produce a lens that yields the most acceptable rendition of the subject being photographed within a range of constraints that include cost, weight and materials.

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Photography is the science, art, application and practice of creating durable images by recording light or other electromagnetic radiation, either electronically by means of an image sensor, or chemically by means of a light-sensitive material such as photographic film.

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Photojournalism is a particular form of journalism (the collecting, editing, and presenting of news material for publication or broadcast) that employs images in order to tell a news story.

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Pinhole camera

A pinhole camera is a simple camera without a lens but with a tiny aperture, a pinhole – effectively a light-proof box with a small hole in one side.

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In biology, poisons are substances that cause disturbances in organisms, usually by chemical reaction or other activity on the molecular scale, when an organism absorbs a sufficient quantity.

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Portrait photography

Portrait photography or portraiture in photography is a photograph of a person or group of people that captures the personality of the subject by using effective lighting, backdrops, and poses.

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Preferred number

In industrial design, preferred numbers (also called preferred values or preferred series) are standard guidelines for choosing exact product dimensions within a given set of constraints.

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Pupil magnification

The pupil magnification of an optical system is the ratio of the diameter of the exit pupil to the diameter of the entrance pupil.

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In mathematics, a ratio is a relationship between two numbers indicating how many times the first number contains the second.

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Reciprocity (photography)

In photography reciprocity is the inverse relationship between the intensity and duration of light that determines the reaction of light-sensitive material.

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Rodenstock Imagon

The Rodenstock Imagon is an achromat doublet photographic lens design uncorrected for spherical aberration used together with diffusion discs ("sink strainers") called sieve aperture (in German).

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Royal Photographic Society

The Royal Photographic Society of Great Britain, commonly known as the Royal Photographic Society (RPS), is one of the world's oldest photographic societies.

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Shutter speed

In photography, shutter speed or exposure time is the length of time when the film or digital sensor inside the camera is exposed to light, also when a camera's shutter is open when taking a photograph.

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Siegfried Czapski

Siegfried Czapski (born 28 May 1861 on the Obra estate near Koschmin in the province of Poznań; died 29 June 1907 in Weimar) was a German physicist and optician.

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Smooth Trans Focus

The Smooth Trans Focus (STF) technology in photographic lenses uses an apodization filter to realize notably smooth bokeh with rounded out-of-focus highlights in both the foreground and background.

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is a Japanese multinational conglomerate corporation headquartered in Kōnan, Minato, Tokyo.

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Southern Astrophysical Research Telescope

The Southern Astrophysical Research (SOAR) telescope is a modern aperture optical and near-infrared telescope located on Cerro Pachón, Chile at elevation.

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Square root of 2

The square root of 2, or the (1/2)th power of 2, written in mathematics as or, is the positive algebraic number that, when multiplied by itself, gives the number 2.

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Sunny 16 rule

In photography, the sunny 16 rule (also known as the sunny rule) is a method of estimating correct daylight exposures without a light meter.

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The Tessar is a famous photographic lens design conceived by the German physicist Paul Rudolph in 1902 while he worked at the Zeiss optical company and patented by Zeiss in Germany; the lens type is usually known as the Zeiss Tessar.

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Thomas Rudolphus Dallmeyer

Thomas Rudolphus Dallmeyer (16 May 1859 – 25 December 1906),"Obituary; Thomas Rudolphus Dallmeyer" (1907) The Photographic Journal, Vol.

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Transmittance of the surface of a material is its effectiveness in transmitting radiant energy.

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Tropicamide, sold under the brand name Mydriacyl among others, is a medication used to dilate the pupil and help with examination of the eye.

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In photography and optics, vignetting (vignette) is a reduction of an image's brightness or saturation toward the periphery compared to the image center.

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[1] https://en.wikipedia.org/wiki/F-number

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