Celestron PowerSeeker 70AZ Telescope PowerSeeker 40AZ Manual (English, French, - Page 9
Installing the Eyepiece on the Newtonian, Installing & Using the Barlow Lens, Installing & - images
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Installing the Eyepiece on the Newtonian The eyepiece (or ocular) is an optical element that magnifies the image focused by the telescope. Without the eyepiece it would be impossible to use the telescope visually. Eyepieces are commonly referred to by focal length and barrel diameter. The longer focal length (i.e., the larger the number) the lower the eyepiece magnification (i.e., power). Generally, you will use low-tomoderate power when viewing. For more information on how to determine power, see the section on "Calculating Magnification". The eyepiece fits directly into the focuser of the Newtonian. To attach the eyepieces: 1. Make sure the thumbscrews are not protruding into the focuser tube. Then, insert the chrome barrel of the eyepiece into the focus tube (remove the plug up cap of the focuser first) and tighten the thumbscrews - see Figure 2-15. 2. The 20mm eyepiece is called an erecting eyepiece since it corrects the image so it is right side up and corrected left to right. This makes the telescope useful for terrestrial viewing. 3. The eyepieces can be changed by reversing the procedure as described above. Figure 2-15 Installing & Using the Barlow Lens Your telescope also comes with a 3x Barlow Lens (2x with the 40AZ) which triples the magnifying power of each eyepiece (doubled for 2x 40AZ). However, the greatly magnified images should only be used under ideal conditions - see the Calculating Magnification section of this manual. Barlow Lens Figure 2-16 To use the Barlow lens with refractors, remove the diagonal and insert the Barlow directly into the focuser tube. You then insert an eyepiece into the Barlow lens for viewing. You can also, insert the diagonal into the Barlow lens and then use an eyepiece in the diagonal but you may not be able to reach focus with all eyepieces. For Newtonian telescopes, insert the Barlowlens directly into the focuser. Then, insert an eyepiece into the Barlow lens. Note: Start by using a low power eyepiece as it will be easier to focus. Installing & Using the 1.5x Erecting Eyepiece - 40AZ & 50AZ The PowerSeeker 50AZ comes with a 1.5x erecting eyepieces, primarily for daytime terrestrial viewing. This eyepiece corrects the image you see in your telescope, so that it's both right side up and corrected from left to right. Install and use this eyepiece the same way you do with the Barlow Lens in the section above. You cannot use the Barlow lens when using this eyepiece. When using the erecting eyepiece, the power with various eyepieces is: 50AZ w/20mm = 45x w/12mm = 75x w/4mm = 225x 40AZ w/20mm = 38x w/8mm = 94x 9