SOME TECHNICALITIES EXPLAINED
NEWTONIAN REFLECTING TELESCOPE
The basic design of a Newtonian telescope is shown in the figure. Light rays from a distant object (like a star) strike the main concave mirror as a parallel beam of rays and is reflected back as a convergent beam. This convergent beam, which would otherwise form an image of the object right in front of the mirror, is intercepted by a small flat mirror called the diagonal (or secondary) mirror placed on the axis of the main mirror at 45 degrees and is deflected at 90 degrees outside the tube where it forms the image of the object. This image is then magnified by an eyepiece.
RESOLVING POWER
It is the ability of a telescope to shown two closely situated objects separately as close double stars that are seen as single by the naked eye but split into two by the telescope. This ability or the resolving power increases as the diameter of the mirror increases provided always that the mirror has excellent optical quality as supplied by SHARP VISION telescopes. Thus, a large mirror telescope will have higher resolution and will show more details in an object at higher magnifications.
LIGHT GATHERING POWER
The brightness of an object as seen by a telescope depends on the size of the mirror used. Larger the mirror, more the light it will gather and brighter the image it will form. A bright image is needed to see details in faint deep sky objects like galaxies and nebulae. The images above represent only a comparative image brightness of different mirror size telescopes.
So, the basic rule in telescopes is bigger the better. Of course to see properly, the telescope should be supported by a sturdy stand to show a vibration free image.
MAGNIFICATION POWER
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The magnification power is defined as the focal length of the objective divided by the focal length of the eyepiece. Thus. a long focal length objective with a short focal length eyepiece will give a high magnification. For viewing planets, a minimum of 30x power is required to see their shapes but around 60x rto 70x will show them in good detail. Higher powers will show more and more details. The three photos above show how an object (top of a water tank) looks like with the naked eye, at 35x power and at 70x power with our STAR GAZER (90 mm mirror dia.) model telescope. Enlarge the first photo to see the red circle and arrow pointing at the top of water tank.