Focus

FOCUS is a software product of Information Builders Inc. Originally developed for data handling and analysis on the IBM mainframe, as newer systems were developed and smaller computers became more powerful, ...

Focus On:
Cassiopeia A
Through a series of observations in 2004, the Chandra X-ray Observatory accumulated a million seconds of observations on Cassiopeia A, a remnant of a supernova explosion.

Newtonian Focus
Related Category: Astronomy: General
see telescope.
More on Newtonian Focus
Telescope - traditionally, a system of lenses, mirrors, or both, used to gather light from a distant object and form an image of it.

Horoscopes Versus Telescopes: A Focus on Astrology

A Note from the Editor: ...

Focusing
In order for light rays to be brought to a focus they must be refracted. The amount of refraction required depends on the distance of the object which is being viewed. A distant object will require less bending of light than a nearer one.

focus One of two special points within an ellipse, whose separation from each other indicate the eccentricity. In a bound orbit, objects move in ellipses about one focus.

Focuser was changed to a small 1.25 inch PVC tube fitting mounted in a block of maple and the spider was replaced with a single bend hacksaw blade (see an article written by Gary Seronik in April 2002 issue of Sky and Telescope): ...

focuser
the device on a telescope that holds an eyepiece and moves to allow an observer to bring light to a sharp focus
fork mount ...

Focus Camera
Refer to Adorama. Same comments apply.
Pauli's Wholesale Optical
A lot of bad reports, order at your own risk! ...

Focuser The part of the telescope which varies the optical distance between the objective lens or primary mirror and the eyepiece.

Focus
The points around which an ellipse is drawn
Forward Scattering ...

Focus - Focus is when the focal plane of an optical system is coincident with the focal plane of an eyepiece or digital camera.

Focus - One of two points from which an ellipse is generated. For all points on the ellipse, the sum of the distances to the two foci is the same
Force - A push or a pull ...

The focus on the "Other"
It is often argued that Anthropology originated and developed as the study of the "Other", both in terms of time (past societies) and space (non-European/non-Western societies).

prime focus: The point at which the objective mirror forms an image in a reflecting telescope.
primeval atmosphere: Earth's first air, composed of gases from the solar nebula.

Prime Focus
The focal point of the large primary reflecting mirror in astronomical telescopes when the light source is extremely distant.

Prime focus
In a prime focus design in large observatory telescopes, the observer sits inside the telescope, at the focal point of the reflected light. In the past this would be the astronomer himself, but nowadays CCD cameras are used.

A deep-focus earthquake is an earthquake that occurs at depths between 300 and 700 km beneath the Earth's surface.

Focussing X-rays is not easy. There is no known material which will refract X-rays by any significant amount, so it is impossible to create a conventional lens. However, alternatives to the refracting lens do exist.

FOCUSER
The focuser is a knob on a telescope that brings the image into focus. It works by moving the eyepiece in and out a slight amount.

focus - Point where the rays of light converged by a mirror or lens meet.
Fraunhofer line - An absorption line in the spectrum of the sun or a star.
Fraunhofer spectrum - The array of absorption lines in the spectrum of the sun or of a star.

By focusing on the Orion Nebula (M42) almost continuously for 13 days, a team of scientists used Chandra to obtain the deepest X-ray observation ever taken of this or any star cluster.

The focusing of light from a distant object by an intervening massive object to change the apparent brightness or produce multiple images of the distant object.
Site Map
Glossary ...

"By focusing on the glow of the ring's cool dust, Spitzer made it easy to find," says Verbiscer.

Prime focus, barlow or variable projection.
Prime focus can work with most scopes
A barlow or Variable projection may NOT work depending on the scope's focuser travel.
Control image brightness and contrast by: ...

Prime Focus
The location where light reflected from the primary mirror of a reflecting telescope comes into focus.

prime focus - (n.)
The location at which the main lens or mirror of a telescope focuses an image without being reflected or refocused by another mirror or other optical element.

(a) A focus used primarily for spectroscopy. In this arrangement light from the primary mirror is reflected along the polar axis to focus at a fixed place separate from the moving parts of the telescope, ...

Do not focus on the symptoms. There are usually two sides at work in those who suffer from test anxiety. One part thinks you will fail and that you are not worthy. The other part of you blames yourself for being so test anxious. It is a vicious cycle.

Let me focus on three items:
---what are Kepler's laws, what do they mean, and why are they important.
The laws were formulated between 1609 to 16l9, and are (as usually stated): ...

Hunter focused primarily on the solar cycle and the Milankovitch cycles. Milankovitch cycles are a set of patterns in Earth's movement that affect the climate.

While the focus is on star birth, Orion, filled with massive stars, must also be a place for stellar death, and not quiet death either.

Today, the focus is on designing and building spacecrafts that can enter any atmosphere in our solar system and return without suffering significant damage.

The series focused on several races that were first featured on TNG, such as the Bajorans, the Cardassians, the Trill and the Ferengi. Later, the Klingons and the Romulans (both created in TOS) became pivotal species in the series.

ULYSSES PRIME FOCUS HGA
Dish-shaped HGAs are the spacecraft antennas principally used for long-range communications with Earth.

Finally let's focus on the center of our Galaxy and the mystery there. As mentioned repeatedly, the galactic nucleus is not visible in optical light. It can be studied, however, in light from other parts of the electromagnetic spectrum.

perifocus (NASA SP-7, 1965) The point on an orbit nearest the dynamical center ( focus). The pericenter is at one end of the major axis of the orbital ellipse.

Some of the largest reflectors in the world use a geometry called the primary focus. The astronomer actually sits in a chair (actually a cage) INSIDE the telescope. S/he sits near the focal point of the primary mirror.

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153. Focus
The points around which an ellipse is drawn.

Because the eye focuses laser light as it does other light, the chief danger in working with lasers is eye damage. Therefore, laser light should not be viewed either directly or reflected.

Philosophical focus
Historian Jacques Barzun termed science "a faith as fanatical as any in history" and warned against the use of scientific thought to suppress considerations of meaning as integral to human existence.

Rack-and-pinion focuser A device that is used to move the drawtube of a telescope so that the eyepiece is correctly focussed.

parabola An open curve all points of which are equidistant from a fixed point, called the focus , and a straight line. See conic section. The limiting case occurs when the point is on the line, in which case the parabola becomes a straight line.

The planets orbit the Sun in elliptical orbits, with the Sun as one common focus.
The line between a planet and the Sun (the radius vector) sweeps out equal areas in equal periods of time (sometimes called the Law of Equal Areas).

The eyepiece is the part of the telescope that focuses the image to your eye. Eyepieces can also be used to magnify the image up to several hundred times.

Throughout his career Darwin wrote two kinds of books--those with a broad canvas, such as the evolution quartet, and those with a narrow focus, such as the treatise on barnacles. His interests shifted over the years from geology to zoology to botany.

This relatively recent focus on atmospheric turbulence is exemplified by the contrasting discussions found in Norton's Star Atlas, then and now.

During the Lunar Orbiter missions, the high resolution cameras had been focused on promising sites strung out along a 10-degree-wide band straddling the lunar equator.

focus), Franz von Paula Triesnecker made a series of measurements at the observatory of Vienna which has been reduced by Dr Wilhelm Schur of Strasburg (Nova Acta der Ksl. Leop.-Carol. Deutschen Akademie der Natursforscher, 1882, xlv. No. 3).

Nasmyth focus
National Astronomy and Ionosphere Center
National Optical Astronomy Observatories (NOAO)
National Radio Astronomy Observatory (NRAO)
National Solar Observatory (NSO)
near-Earth asteroid
near-Earth object (NEO)
nearest stars ...

It accounts for the focusing action of lenses. In dialling, use is made of ~ in dials which use a clear liquid in a solid cup to compress the hour lines, or which use a cylindrical lens to focus sunlight onto a curved dial plate.

Planets move in ellipses with the Sun at one focus. (See Figure 9) There are several aspects that can be explained by using an ellipse and not a circle to explain the planetary motions.

The global warming debate has focused on CO2 as a greenhouse gas. There is no serious debate over whether carbon dioxide is a greenhouse gas.

The sun occupies one of the two focus points of the ellipse. Because this focus point is not at the center of the orbit, ...

With a moving mirror-focuser telescope (such as a Schmidt-Cassegrain) the actual focal length of the scope is rather difficult to determine because it changes slightly as the main mirror moves during focusing and also because the use of a diagonal ...

Even if no trans-Plutonian planet ever was found, the interest was focused to the outer parts of the solar system. The erratic asteroid Hidalgo, moving in an orbit between Jupiter and Saturn, has already been mentioned.

A telescope is an optical instrument that gathers and focuses light into a camera, CCD, spectrograph, or an astronomer's eye. Two major types of telescopes dominate astronomy: reflectors and refractors.

When you look at the filament, its image is focused onto your retina in your eye and that image contains the full painful brightness of the filament.

" The focus was on the interplay between solar convection and the magnetic field in and near the photosphere.

Attention has recently focussed on the aftermath of a violent starburst, when some stars become extreme WR objects with effective temperatures near 105 K (sound familiar?).

See also: Time, Light, Second, Earth, Field