Celestron C21061 manual Image Orientation, Focusing, Aligning the Finderscope

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Image Orientation

Image Orientation

The image orientation changes depending on how the eyepiece is inserted into the telescope. When using a star diagonal with refractors, the image is right-side-up, but reversed from left-to-right (i.e., mirror image). If inserting the eyepiece directly into the focuser of a refractor (i.e., without the diagonal), the image is upside-down and reversed from left-to-right (i.e., inverted). However, when using the AstroMaster refractor and the standard erect image diagonal, the images is correctly oriented in every aspect.

Newtonian reflectors produce a right-side-up image but the image will appear rotated based on the location of the eyepiece holder in relation to the ground. However, by using the erect image eyepiece supplied with the AstroMaster Newtonians, the image is correctly oriented.

Image orientation as seen with the unaided eye & using erecting devices on refractors & Newtonians

Reversed from left to right, as

viewed using a Star Diagonal on a

refractor

Figure 3-3

Inverted image, normal with Newtonians & as viewed with eyepiece directly in a refractor

Focusing

To focus your refractor or Newtonian telescope, simply turn the focus knob located directly below the eyepiece holder (see Figures 1-1 and 1-2). Turning the knob clockwise allows you to focus on an object that is farther than the one you are currently observing. Turning the knob counterclockwise from you allows you to focus on an object closer than the one you are currently observing.

Note: If you wear corrective lenses (specifically glasses), you may want to remove them when observing with an eyepiece attached to the telescope. However, when using a camera you should always wear corrective lenses to ensure the sharpest possible focus. If you have astigmatism, corrective lenses must be worn at all times.

Aligning the Finderscope

The Star Pointer is the quickest and easiest way to point your telescope exactly at a desired object in the sky. It's like having a laser pointer that you can shine directly onto the night sky. The Star Pointer is a zero magnification pointing tool that uses a coated glass window to superimpose the image of a small red dot onto the night sky. While keeping both eyes open when looking through the Star Pointer, simply move your telescope until the red dot, seen through the Star Pointer, merges with the object as seen with your unaided eye. The red dot is produced by a light-emitting diode (LED); it is not a laser beam and will not damage the glass window or your eye. The star pointer is powered by a long life 3-volt lithium battery (#CR1620) see Figure 3-4. Like all finderscopes, the Star Pointer must be properly aligned with the main telescope before it can be used. The alignment procedure is best done at night since the LED dot will be difficult to see during the day.

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Contents AstroMaster Series Telescopes Table of Contents Quick and easy no-toolset up 8 9 Figure 1-1AstroMaster 90AZ Refractor 8 9 Figure 1-2AstroMaster 114 AZ Newtonian Setting up the Tripod Moving the Telescope Manually Attaching the Telescope Tube to the Mountin step 2 above Installing the Diagonal & Eyepieces refractorInstalling the Eyepieces on the Newtonians telescope useful for terrestrial viewingPage Image Orientation FocusingAligning the Finderscope Switch Calculating MagnificationBattery Compartment Focal Length of Telescope mmDetermining Field of View General Observing HintsThe Celestial Coordinate System Motion of the Stars Observing the Sun Observing the MoonObserving the Planets Lunar Observing HintsObserving Deep Sky Objects Star Hopping4.Point about halfway between these two stars Sky Illumination Seeing ConditionsTransparency SeeingCCD Imaging for Deep Sky Objects Short Exposure Prime Focus PhotographyPiggyback Photography Terrestrial PhotographyCollimation of a Newtonian Care and Cleaning of the OpticsAigning the Secondary Mirror Aligning the Primary Mirror Night Time Star Collimatingto achieve the necessary mirror movement You will find that additional accessories for your AstroMaster telescope will enhance your viewing pleasure and expand the usefulness of your telescope. This is just a short listing of various accessories with a brief description. Visit the Celestron website or the Celestron Accessory Catalog for complete descriptions and all accessories available AstroMaster SpecificationsNote Specifications are subject to change 21061Celestron Copyright 2007 Celestron All rights reserved