Secondary mirror cage
Also in March, I got Baltic Birch plywood through a local cabinet maker. Router was used to cut rings which were then assembled with sections of 1.25 inch tubing and focuser board to form the structure shown below.
secondary mirror
a relatively small mirror used in a telescope to redirect the light gathered by the primary mirror
seeing ...
Secondary Mirror
The second reflecting surface encountered by the light in a telescope. The secondary is usually suspended in the beam and therefore obstructs part of the primary.
Secular ...
Secondary Mirror
In a reflecting telescope, the mirror that reflects the image to a point for easy observation
Seeing ...
Secondary Mirror
A small flat or curved mirror that intercepts light coming from the primary mirror of a reflecting telescope and directs it into an eyepiece. In Newtonian reflectors, the secondary mirror is often referred to as the diagonal.
Secondary mirror
A small mirror in a reflecting telescope that redirects light from the larger primary mirror toward the light-sensitive scientific instruments.
Secondary mirror - In reflecting telescopes, the smaller mirror that reflects light from the primary mirror to the eyepiece.
View the secondary mirror holder from the corrector plate end of the Schmidt-Cassegrain Telescope. The collimation screw nearest the ground is labeled "A". Screws "B" and "C" are as shown in the center of the diagram above.
Doesn't the secondary mirror block the view?
Not really, although it's easy to think it might. Plenty of the image comes into the tube around the secondary mirror.
Light is collected by the primary mirror and directed to a smaller secondary mirror that channels it through a hole in the center of the primary mirror and onto the CCD.
The Cassegrain (sometimes called the "Classic Cassegrain") has a parabolic primary mirror, and a hyperbolic secondary mirror that reflects the light back down through a hole in the primary. Folding the optics makes this a compact design.
The simplest of these, constituting the Newtonian reflector, is the placement of a flat secondary mirror in the path of the converging light just before the prime focus.
Often a secondary mirror is used to redirect the light into a more convenient viewing spot. The secondary mirror and its supports can produce diffraction effects: bright objects have spikes (the ``christmas star effect'').
Because the mirror focuses the light back along its central axis, the secondary mirror must be on that axis, causing it to block the central portion of the light path.
Used for Lunar and planetary work should have focal ratios from f/6 to f/12 with small diameter secondary mirrors.
3-m (12-inch), secondary mirror, which in turn sends the light through a hole in the doughnut-shaped main mirror and into the aft bay of the spacecraft. There, any of five major scientific instruments wait to analyze the incoming radiation.
The primary mirror then reflects the light back toward the corrector plate which has a small convex secondary mirror coated onto the centre of the corrector plate.
It is then reflected to a small secondary mirror attached to the front corrector plate. From there it is then reflected through a small hole in the back of the primary mirror.
devised in the 18th century, the objective prism spectrograph is the simplest design possible; a prism large enough to cover the aperture of the telescope is placed in front of the objective lens (or the aperture in front of the secondary mirror, ...
A reflector uses a large primary mirror and a smaller secondary mirror to bounce the incoming light through to a lens. It has the advantage of being relatively cheap to produce (and therefore buy).
This is too fast for altering a primary mirror so adaptive optic systems are designed to act via the secondary mirror and additional optical elements placed in the light path.
It is a reflecting telescope with a concave parabolic primary mirror and a convex hyperbolic secondary mirror.
It was made from inch-thick deal staves, hooped with iron clamp rings and strengthened by iron diaphragms; at the top was the secondary mirror, which was so heavy it had to be counterpoised.
Central Obstruction
This is the secondary mirror in a reflecting telescope. It blocks some of the light reaching the primary mirror, but not usually enough to degrade the final image.
Secondary Abbreviation for secondary mirror. Small mirror that directs the light from the primary mirror to the eyepiece.
Semi-major Axis Half the distance across an ellipse measured along a line through its foci.
The Gregorian design consists of a concave secondary mirror, located outside the prime focus and angled to reflect the light back through a hole in the primary mirror (as is also done in a ).
As the diagram illustrates light travels down the tube where it is reflected (hence the name reflector) up to a secondary mirror near the top of the tube which directs the light into the eyepiece. This exact system is known as a Newtonian Reflector.
Refers to a design of reflecting telescopes in which the light collected and focussed by the large concave primary mirror is refocussed by a smaller convex secondary mirror on the same axis as the primary.
coude focus - An optical arrangement in a reflecting telescope whereby light is reflected by two or more secondary mirrors down the polar axis of the telescope to a focus at a place separate from the moving parts of the telescope.
In order to achieve this focus, a reflecting telescope must have a secondary mirror and a hole cut in the center of the primary mirror.
A type of reflecting telescope where the beam reflected by the primary mirror is reflected by a flat secondary mirror so that the focus falls to the side of the telescope tube.
New General Catalogue (NGC) - (n.) ...
First astronomers had to calibrate the new gyroscopes, allow the WF/PC's new electronic detectors to cool to operating temperatures and align the Hubble's secondary mirror to make sure light properly entered the improved WF/PC.
As a rule of thumb, remember that an even number of reflections will give you an inverted (upside-down) image, such as a Newtonian telescope, since primary and secondary mirrors amount to two reflections.
The secondary mirror is adjusted up to 500 times per second by computer to compensate for the rapid distortions caused by the Earth's turbulent atmosphere.
In this disk is cut a circular opening of much smaller diameter; in reflectors, the openings must be cut to one side so that they are clear of the secondary mirror support.
Active control of the shape of the primary and secondary mirrors corrects for errors in tracking, compensates for buffetting of the telescopes by the wind and provides some compensation for the blurring effects of the Earth's atmosphere.
 See also: Second, Telescope, Light, Primary, Focus
  
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