optics

Top: The formation of a virtual image using a diverging lens. Bottom: The formation of a virtual image using a convex mirror. In both diagrams, f is the focal point, O is the object and I is the image, shown in grey ...

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Top: The formation of a real image using a convex lens. Bottom: The formation of a real image using a concave mirror. In both diagrams, f is the focal point, O is the object, and I is the image.

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In an imperfect lens L, all the rays do not pass through a focal point. The smallest circle that they pass through C is called the circle of least confusion.

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This is a major advantage for solar telescopes, where a field stop (Gregorian stop) can reduce the amount of heat reaching the secondary mirror and subsequent optical components.

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In the Gregorian design, the primary mirror creates a real image before the secondary mirror. This allows for a field stop to be placed at this location, so that the light from outside the field of view does not reach the secondary mirror.

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The classic Cassegrain telescope has a parabolic primary mirror and a hyperbolic secondary mirror

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TRAIL: Webel SysML Parsing Analysis example: Optical telescopes from Wikipedia: Structure and port-based light flow model

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SysML Block Definition Diagram (BDD)

The Newtonian telescope has flat secondary mirror and a paraboloid or spherical primary mirror

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TRAIL: Webel SysML Parsing Analysis example: Optical telescopes from Wikipedia: Structure and port-based light flow model

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SysML Block Definition Diagram (BDD)

In optics, 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 ("clear aperture"). It is also known as the focal ratio, f-ratio, or f-stop

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The Gregorian telescope employs a concave secondary mirror that reflects the image back through a hole in the primary mirror.

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TRAIL: Webel SysML Parsing Analysis example: Optical telescopes from Wikipedia: Structure and port-based light flow model

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SysML Block Definition Diagram (BDD)

A curved primary mirror is the reflector telescope's basic optical element

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TRAIL: Webel SysML Parsing Analysis example: Optical telescopes from Wikipedia: Structure and port-based light flow model

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SysML Block Definition Diagram (BDD)

KeplerianRefractor: simple image flow model: context IBD with itemProperty

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Tutorial

TRAIL: Webel SysML Parsing Analysis example: Optical telescopes from Wikipedia: Structure and port-based light flow model

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SysML Internal Block Diagram (IBD)

KeplerianRefractor: simple image flow model: staging BDD

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Tutorial

TRAIL: Webel SysML Parsing Analysis example: Optical telescopes from Wikipedia: Structure and port-based light flow model

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SysML Block Definition Diagram (BDD)

SimpleOpticalTelescope light flow model: staging BDD and context IBD

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TRAIL: Webel SysML Parsing Analysis example: Optical telescopes from Wikipedia: Structure and port-based light flow model

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Slide kind

SysML Block Definition Diagram (BDD)

SysML Internal Block Diagram (IBD)

IBD of a SimpleOpticalTelescope in context with some relationships

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Tutorial

TRAIL: Webel SysML Parsing Analysis example: Optical telescopes from Wikipedia: Structure and port-based light flow model

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SysML Internal Block Diagram (IBD)

The basic scheme of an optical telescope: Keplerian refractor

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TRAIL: Webel SysML Parsing Analysis example: Optical telescopes from Wikipedia: Structure and port-based light flow model

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SysML Block Definition Diagram (BDD)

rays that enter the system parallel to the optical axis are focused such that they pass through the rear focal point

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A principal focus or focal point is a special focus: For a lens, or a spherical or parabolic mirror, it is a point onto which collimated light parallel to the axis is focused.

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If the medium surrounding the optical system has a refractive index of 1 (e.g., air or vacuum), then the distance from the principal planes to their corresponding focal points is just the focal length of the system.

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The front and rear (or back) focal planes are defined as the planes, perpendicular to the optic axis, which pass through the front and rear focal points.

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An object infinitely far from the optical system forms an image at the rear focal plane.

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An object infinitely far from the optical system forms an image at the rear focal plane

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Tutorial

TRAIL: Webel SysML Parsing Analysis example: Optical telescopes from Wikipedia: Structure and port-based light flow model

Section

Slide kind

SysML Block Definition Diagram (BDD)

Although the focus is conceptually a point, physically the focus has a spatial extent, called the blur circle. This non-ideal focusing may be caused by aberrations of the imaging optics.

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In geometrical optics, a focus, also called an image point, is the point where light rays originating from a point on the object converge.

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A real image occurs where rays converge, whereas a virtual image occurs where rays only appear to diverge.

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In ray diagrams ... real rays of light are always represented by full, solid lines; perceived or extrapolated rays of light are represented by dashed lines.

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A real image ... is an image which is located in the plane of convergence for the light rays that originate from a given object.

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A converging lens (one that is thicker in the middle than at the edges) or a concave mirror is also capable of producing a virtual image if the object is within the focal length. Such an image will be magnified.

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A diverging lens (one that is thicker at the edges than the middle) or a convex mirror forms a virtual image. Such an image is reduced in size when compared to the original object.

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Because the rays never really converge, a virtual image cannot be projected onto a screen. In contrast, a real image can be projected on the screen as it is formed by rays that converge on a real location.

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In diagrams of optical systems, virtual rays are conventionally represented by dotted lines.

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a virtual image is found by tracing real rays that emerge from an optical device (lens, mirror, or some combination) backward to perceived or apparent origins of ray divergences.

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A real image is the collection of focus points actually made by converging rays, while a virtual image is the collection of focus points made by extensions of diverging rays.

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In optics, an image is defined as the collection of focus points of light rays coming from an object.

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Optics: real images vs virtual images and focus points

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Tutorial

TRAIL: Webel SysML Parsing Analysis example: Optical telescopes from Wikipedia: Structure and port-based light flow model

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Slide kind

SysML Block Definition Diagram (BDD)

Objectives can be a single lens or mirror, or combinations of several optical elements.

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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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For example, in a telescope, the aperture stop is typically the edges of the objective lens or mirror (or of the mount that holds it). One then speaks of a telescope as having, for example, a 100-centimeter aperture.

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In some contexts, especially in photography and astronomy, aperture refers to the diameter of the aperture stop rather than the physical stop or the opening itself.

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Optical radiation is part of the electromagnetic spectrum. It is subdivided into ultraviolet radiation (UV), the spectrum of light visible for man (VIS) and infrared radiation (IR). It ranges between wavelengths of 100 nm to 1 mm [DISPUTED]

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Australian Astronomical Optics (AAO) Macquarie University

The Drancel light synthesis system

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This zone is dedicated to applications of the Drancel system to direct light synthesis (as opposed to computer-generated digital visuals).

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