f-number

A photographic lens (or more correctly, objective) is an optical lens 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. While in principle a simple convex lens will suffice, in practice a compound lens made up of a number of optical lens elements is required to correct the many optical aberrations that arise. There is no difference in principle between a lens used for a camera, a telescope, a microscope, or other apparatus, ...

Including:

• Photographic lens - Special purpose photographic lenses

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In most areas of optics, and especially in microscopy, the numerical aperture of an optical system such as an objective lens is defined by where n is the index of refraction of the medium in which the lens is working (1.0 for air, 1.33 for pure water, and up to 1.56 for oils), and θ is the half-angle of the maximum cone of light that can enter or exit the lens. In general, this is the angle of the real marginal ray in the system. The angular aperture of the lens is twice this value. The NA is generally measured with respect to a particular object ...

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Numerical aperture, Numerical aperture - General optics, Numerical aperture - Laser physics, Numerical aperture - Fiber optics, Numerical aperture - Sources

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Photography is the process of making pictures by means of the action of light. It involves recording light patterns, as reflected from objects, onto a sensitive medium through a timed exposure. The process is done through mechanical, chemical or digital devices commonly known as cameras. The word comes from the Greek words φως phos ("light"), and γραφις graphis ("stylus", "paintbrush") or γραφη graphê, together meaning "drawing with light" or "representation by means of lines" or "drawing."Including:

• Photography - Photographic image forming devices
• Photography - Uses of photography
• Photography - History of photography
• Photography - Invention
• Photography - Social history
• Photography - Economic history
• Photography - Color photography
• Photography - Digital photography
• Photography - Digital versus Film
• Photography - Commercial photography
• Photography - Terminology
• Photography - Photography as an art form
• Photography - Aesthetic realism and photography
• Photography - Reference
• Photography - Additional reading
• Photography - Basic topics in photography
• Photography - Photographers
• Photography - Photographs
• Photography - Historical
• Photography - Techniques
• Photography - Photographic products
• Photography - Other

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An eye is an organ that detects light. Different kinds of light-sensitive organs are found in a variety of creatures. The simplest eyes do nothing but detect whether the surroundings are light or dark. More complex eyes are used to provide the sense of vision. Many complex organisms including some mammals, birds, reptiles and fish have two eyes which may be placed on the same plane to be interpreted as a single three-dimensional "image" (binocular vision), as in humans; or on different planes producing two separate "images" (monocular ...

Including:

• Eye - Varieties of eyes
• Eye - Evolution of eyes
• Eye - Anatomy
• Eye - Cytology
• Eye - Acuity
• Eye - Dynamic range
• Eye - Adnexa and related parts
• Eye - The orbit
• Eye - Eyebrows
• Eye - Eyelids
• Eye - Eyelashes
• Eye - Eye movement
• Eye - Rapid eye movement
• Eye - Saccades
• Eye - Microsaccades
• Eye - Vestibulo-ocular reflex
• Eye - Smooth pursuit movement
• Eye - Optokinetic reflex
• Eye - Vergence movement
• Eye - Accommodation
• Eye - Diseases disorders and age-related changes

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Multimode optical fiber will only propagate light that enters the fiber within a certain cone, known as the acceptance cone of the fiber. The half-angle of this cone is called the acceptance angle, θmax. For step-index multimode fiber, the acceptance angle is determined only by the indexes of refraction: , where nf is the refractive index of the fiber core, and nc is the refractive index of the cladding. This has the same form as the numerical aperture in other optical systems, so it has become common to define the ...

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Numerical aperture, Numerical aperture - General optics, Numerical aperture - Laser physics, Numerical aperture - Fiber optics, Numerical aperture - Sources

Read more here: » Numerical aperture: Encyclopedia II - Numerical aperture - Fiber optics

A Zone plate is a device used to focus light. Unlike lenses however, zone plates use diffraction instead of refraction. Created by Augustin-Jean Fresnel, they are sometimes called Fresnel zone plates in his honor. The zone plate's focusing ability is an extension of the Arago spot phenomenon caused by diffraction from an opaque disc. A zone plate consists of a set of radially symmetric rings, known as Fresnel zones, which alternate between opaque and transparent. Light hitting the zone plate will diffract around the opaq ...

Including:

• Zone plate - Design and manufacture
• Zone plate - Applications
• Zone plate - Physics
• Zone plate - Photography

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Due to the wave nature of light, light passing through apertures is diffracted, and the diffraction increases with decreasing aperture size. The resulting diffraction pattern of a uniformly illuminated circular aperture has a bright region in the centre, known as the Airy disc or Airy pattern, which is surrounded by concentric rings. The diameter of this disc is related to the wavelength of the illuminating light and the size (f-number) of the circular aperture. The angle from the center at which ...

Including:

• Airy disc - Mathematical Details

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In laser physics, the numerical aperture is defined slightly differently. Laser beams spread out as they propagate, but slowly. Far away from the narrowest part of the beam, the spread is roughly linear with distance—the laser beam forms a cone of light in the "far field". The same relation gives the NA, , but θ is defined differently. Laser beams typically do not have sharp edges like the cone of light that passes through the aperture of a lens does. Instead, the irradiance falls off gradually away from ...

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Numerical aperture, Numerical aperture - General optics, Numerical aperture - Laser physics, Numerical aperture - Fiber optics, Numerical aperture - Sources

Read more here: » Numerical aperture: Encyclopedia II - Numerical aperture - Laser physics

Photography - Invention. Main articles: History of the camera, and [[]], and [[]], and [[]]See also:

Photography, Photography - Photographic image-forming devices, Photography - Uses of photography, Photography - History of photography, Photography - Invention, Photography - Social history, Photography - Economic history, Photography - Color photography, Photography - Digital photography, Photography - Digital versus film, Photography - Commercial photography, Photography - Terminology, Photography - Photography as an art form, Photography - Aesthetic realism and photography, Photography - Reference, Photography - Additional reading, Photography - Basic topics in photography, Photography - Photographers, Photography - Photographs, Photography - Historical, Photography - Techniques, Photography - Photographic products, Photography - Other

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How a complex structure like the projecting eye could have evolved is often said to be a difficult question for the theory of evolution. Darwin famously treated the subject of eye evolution in his Origin of Species: To suppose that the eye, with all its inimitable contrivances for adjusting the focus to different distances, for admitting different amounts of light, and for the correction of spherical and chromatic aberration, could have been formed by natural selection, seems, I freely confess, absurd in the highest possible ...

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Eye, Eye - Varieties of eyes, Eye - Evolution of eyes, Eye - Anatomy, Eye - Cytology, Eye - Acuity, Eye - Dynamic range, Eye - Adnexa and related parts, Eye - The orbit, Eye - Eyebrows, Eye - Eyelids, Eye - Eyelashes, Eye - Eye movement, Eye - Rapid eye movement, Eye - Saccades, Eye - Microsaccades, Eye - Vestibulo-ocular reflex, Eye - Smooth pursuit movement, Eye - Optokinetic reflex, Eye - Vergence movement, Eye - Accommodation, Eye - Diseases disorders and age-related changes

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Process and apochromat lenses are normally of small aperture, and are used for extremely accurate photographs of static objects. Enlarger lenses are made to be used with photographic enlargers (specialised projectors), rather than cameras. Lenses for aerial photography Fisheye lenses: extreme wide-angle lenses with an angle of view of 180 degrees, with very noticeable distortion. Stereoscopic lenses, to produce pairs of photographs which give a 3-dimensional effect when viewed with an appropriate viewe ...

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Photographic lens, Photographic lens - Special purpose photographic lenses

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To get constructive interference at the focus, the zones should switch from opaque to transparent at radii where where n is an integer, λ is the wavelength of the light the zone plate is meant to focus and f is the distance from the center of the zone plate to the focus. Note that this formula is an approximation only valid when the zone plate is small compared to t ...

See also:

Zone plate, Zone plate - Design and manufacture, Zone plate - Applications, Zone plate - Physics, Zone plate - Photography

Read more here: » Zone plate: Encyclopedia II - Zone plate - Design and manufacture

The intensity of the Fraunhofer diffraction pattern of a circular aperture is given by: where J1 is a Bessel function of the first kind, a is the radius of the disc, and . The first zero of J1(x) is where x = 3.83, so the first zero of the ...

See also:

Airy disc, Airy disc - Mathematical Details

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Nikon is listed in the Tokyo Stock Exchange under number 7731. (as of September 2004) The Master Trust Bank of Japan, Ltd. (8.5%) Meiji Yasuda Life Insurance Company (5.6%) The Bank of Tokyo-Mitsubishi, Ltd. (3.3%) Japan Trustee Services Bank, Ltd.(2.9%) Tokio Marine & Nichido Fire Insurance Co., Ltd. (2.7%) State Street Bank and Trust Company (2.7 %) The Mitsubishi Trust and Banking Corporation (2.5%) Nippon Life Insurance Company (2.4%) The Joyo Bank, Ltd. (1.8%) < ...

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Nikon Corporation, Nikon Corporation - Shareholders, Nikon Corporation - Holdings, Nikon Corporation - Partial list of Nikon products, Nikon Corporation - Cameras, Nikon Corporation - Lenses, Nikon Corporation - Flash Guns

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Nikon is listed in the Tokyo Stock Exchange under number 7731. (As of September 2004) The Master Trust Bank of Japan, Ltd. (8.5%) Meiji Yasuda Life Insurance Company (5.6%) The Bank of Tokyo-Mitsubishi, Ltd. (3.3%) Japan Trustee Services Bank, Ltd.(2.9%) Tokio Marine & Nichido Fire Insurance Co., Ltd. (2.7%) State Street Bank and Trust Company (2.7 %) The Mitsubishi Trust and Banking Corporation (2.5%) Nippon Life Insurance Company (2.4%) The Joyo Bank, Ltd. (1.8%) < ...

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Nikon Corporation, Nikon Corporation - Shareholders, Nikon Corporation - Holdings, Nikon Corporation - Partial list of Nikon products, Nikon Corporation - Cameras, Nikon Corporation - Lenses, Nikon Corporation - Flash guns

Read more here: » Nikon Corporation: Encyclopedia II - Nikon Corporation - Shareholders

To get constructive interference at the focus, the zones should switch from opaque to transparent at radii where where n is an integer, λ is the wavelength of the light the zone plate is meant to focus and f is the distance from the center of the zone plate to the focus. For plates with many zones, you can calculate the distance to the focus if you only know the radius of the outermost zone, r N, and its width, ...

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Zone plate, Zone plate - Design and manufacture, Zone plate - Applications, Zone plate - Physics, Zone plate - Photography

Read more here: » Zone plate: Encyclopedia II - Zone plate - Design and manufacture

In cinematography, shutter speed is a function of the frame rate and shutter angle. Most motion picture film cameras use a rotating shutter with a shutter angle of 170 to 180 °, which leaves the film exposed for about 1/48 or 1/50 second at a standard 24 frame/s. Where E = Exposure, F = Frames per second, and S = Shutter opening: See also: exposure, shutter, f-number, exposure value ...

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Shutter speed, Shutter speed - Cinematographic Shutter Formulae, Shutter speed - Additional Photos

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Most commonly a camera or camera obscura is the image forming device and photographic film or a digital storage card is the recording medium, although other methods are available. For instance, the photocopy or xerography machine forms permanent images but uses the transfer of static electrical charges rather than photographic film, hence the term electrophotography. The rayographs published by Man Ray in 1922 are images produced by the shadows of objects cast on the photographic paper, without the use of a camera. And one can place objects dire ...

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Photography, Photography - Photographic image forming devices, Photography - Uses of photography, Photography - History of photography, Photography - Invention, Photography - Social history, Photography - Economic history, Photography - Color photography, Photography - Digital photography, Photography - Digital versus Film, Photography - Commercial photography, Photography - Terminology, Photography - Photography as an art form, Photography - Aesthetic realism and photography, Photography - Reference, Photography - Additional reading, Photography - Basic topics in photography, Photography - Photographers, Photography - Photographs, Photography - Historical, Photography - Techniques, Photography - Photographic products, Photography - Other

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There are many diseases and disorders that may affect the eyes. As the eye ages certain changes occur that can be attributed to solely the aging process. Most of these anatomic and physiologic processes follow a gradual decline. With aging, the quality of vision worsens due to reasons independent of aging eye diseases. While there are many changes of significance in the nondiseased eye, the most functionally important changes seem to be a reduction in pupil size and the loss of accommodation or focusing capability (presbyopia). The ar ...

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Eye, Eye - Varieties of eyes, Eye - Evolution of eyes, Eye - Anatomy, Eye - Cytology, Eye - Acuity, Eye - Dynamic range, Eye - Adnexa and related parts, Eye - The orbit, Eye - Eyebrows, Eye - Eyelids, Eye - Eyelashes, Eye - Eye movement, Eye - Rapid eye movement, Eye - Saccades, Eye - Microsaccades, Eye - Vestibulo-ocular reflex, Eye - Smooth pursuit movement, Eye - Optokinetic reflex, Eye - Vergence movement, Eye - Accommodation, Eye - Diseases, disorders, and age-related changes

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Eye - The orbit. In many species, the eyes are inset in the portion of the skull known as the orbits or eyesockets. This placement of the eyes helps to protect them from injury. Eye - Eyebrows. In humans, the eyebrows redirect flowing substances (usually rainwater) away from the eye. Water in the eye can alter the refractive properties of the eye and blur vision. It can also wash away the tear fluid - along with it the protective lipid layer - and can alter corneal physiology, ...

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Eye, Eye - Varieties of eyes, Eye - Evolution of eyes, Eye - Anatomy, Eye - Cytology, Eye - Acuity, Eye - Dynamic range, Eye - Adnexa and related parts, Eye - The orbit, Eye - Eyebrows, Eye - Eyelids, Eye - Eyelashes, Eye - Eye movement, Eye - Rapid eye movement, Eye - Saccades, Eye - Microsaccades, Eye - Vestibulo-ocular reflex, Eye - Smooth pursuit movement, Eye - Optokinetic reflex, Eye - Vergence movement, Eye - Accommodation, Eye - Diseases disorders and age-related changes

Read more here: » Eye: Encyclopedia II - Eye - Adnexa and related parts