constellation of Pegasus. The coordinates of the Right Ascension range from 0h 0mn 0s to 24h 0mn 0s (not inclusive). Therefore, there are 24 primary R.A. lines located at 15 degree intervals along the celestial equator. The objets that are further away, eastwards, from the primary Right Ascension grid line (0h 0mn 0s) carry rising R.A. coordinates.
Consequently, once it is possible to specify the position of all of these celestial objects using their Right Ascension and Declination coordinates the task of searching for objects (especially low brightness stars) using the astronomer's telescope may be simplified. The digital, R.A. (16) and Dec.
(13)setting circles for your telescope can be made up, in practice to read the object's coordinates, by positioning it close to the telescope's telescopic field of view (FOV). The advantage of using these setting circles is however only justified after first correctly aligning the telescope with the North Celestial Pole.
3. Getting Started
Before you can use the telescope effectively, there are still a few steps to be performed.
3.1. Selecting an Eyepiece
1.Always begin viewing with the lowest power eyepiece. (Note: a 20 mm focal length eyepiece is lower power than a 12.5 mm one.) A formula can be used to determine the power of each eyepiece: Telescope focal length divided by eyepiece focal length equals magnification. Ex. 900mm ÷ 20mm = 45X (magnification)
2.Included with this telescope is a 45° Erecting Diagonal Prism. The Erecting Diagonal Prism is used to erect the image you will see. Astronomical telescopes are designed in such a way that the image you see may be UPSIDE DOWN and REVERSED. This is acceptable for viewing celestial bodies.
3.2. Focusing Telescope
1.After selecting the desired eyepiece aim the main telescope tube at a
200yards away (e.g. A telephone pole or a building). Fully extend focusing tube by turning the focus knob.
2.While looking through selected eyepiece, slowly retract focusing tube by turning focusing knob until object comes into focus.
3.3. Aligning Finderscope:
The extended field of vision offered by the 5x24
mmfinderscope (8) makes it easier to aim at an object before viewing it through the main telescope tube with a higher magnification.
1). Remove the front lens cover (33) from the sunshade (29). Look through Main Telescope Tube and establish a
2). Looking through the finderscope, alternate tightening or loosing each finderscope Adjustment Screw (9) until the crosshairs of the finderscope are precisely centered on the same object already centered in Main Telescope Tube’s field of view.
3). Now, objects located with the finderscope first will be centered in FOV of the main telescope. They can be focused by turning the finderscope’s threaded eyepiece. The image in the finderscope will be reversed.
3.4. Balancing the Telescope
To insure smooth movement of the telescope on both axes of the equatorial mount, it is imperative that the optical tube be properly balanced. We will first balance the telescope with respect to the right ascension (R.A.) axis and then in the declination (Dec.) axis.
1.Keeping one hand on the telescope optical tube (11), loosen the R.A. lock knob (14). Make sure the Dec. lock knob (12) is locked. The telescope should now be able to rotate freely about the R.A. axis. Rotate it until the counterweight shaft (17) is parallel to the ground (i.e., horizontal).
2.Now loosen the counterweight lock knob (20) and slide the weight along the shaft until it exactly counterbalances the telescope. That’s the point at which the shaft remains horizontal even when you let go of the telescope with both hands.
3.Retighten the counterweight lock knob. The telescope is now balanced on the R.A. axis.
4.To balance the telescope on the Dec. axis, first tighten the R.A. lock knob (14), with the counterweight shaft (17) still in the horizontal position.
5.With one hand on the telescope optical tube (11),
Having trouble setting up or making it work? Email us at 900X70@ioptron.com We’ll be glad to help!
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