Therefore, if you use the 20mm eyepiece your magnification is 700/20 = 35x. The same formula can be applied to any of your eyepieces.

Celestron offers numerous optional eyepieces to expand your range of magnification. Eyepieces come in barrel diameters of .96" and 1¼". In general, 1¼" eyepieces are of a higher optical quality and give you sharper images, along with a wider field of view and better eye relief.

Magnification through the telescope has its limits. These limits are determined by the laws of optics and the nature of the human eye. The maximum usable power (with sharp images) is equal to 60 times the aperture of the telescope (in inches). So, with a 60mm telescope it has a maximum useful power of 144x (2.4" x 60) and with the 70mm the maximum is 165x (2.7559 x 60). Most of your viewing will be done in the range of 30x to 120x. Higher powers are used mainly for lunar and sometimes planetary observing where you can greatly enlarge the image. The images at extremely high powers like 675x magnify the image bur remember that the contrast will be very low and the image somewhat blurred due to the super power. For the brightest images with the most contrast, use the lower powers with a smaller image scale.

TELESCOPE OPERATION — ASTRONOMICAL OBSERVING

Now that your telescope is set up, you’re ready to use it for observing.

Observing the Moon

In the night sky, the moon is a prime target for your first look because it is extremely bright and easy to find. Although the beauty of the full moon may make it seem a perfect viewing object, in fact, the light reflected from its fully illuminated face can be overpowering. In addition, little or no contrast can be seen during this phase.

One of the best times to observe the moon is during its partial phases, such as a crescent or quarter moon. At these times, long shadows reveal a great amount of detail on the lunar surface. At low power, with the standard eyepiece, you’ll be able to see the whole lunar disk at one time. Change to higher power (magnification) to focus in on a smaller area.

Keep in mind that the rotation of the earth will cause the moon to drift out of your field of view. You’ll have to manually adjust the telescope to keep the moon centered. This effect is more noticeable at higher power. Consult a current astronomy magazine or your local newspaper to find out the current phase of the moon.

Lunar Observing Hint

To increase contrast and bring out visible detail on the lunar surface, try using different eyepiece filters (available through your local Celestron dealer). A yellow filter works well for improving contrast.

Observing the Planets

Other easy targets include the five “naked eye” planets of our solar system, so called because they can be spotted in the night sky by the unaided eye. You can see Venus go through its lunar-like phases. Mars can reveal a host of surface detail and one, if not both, of its polar caps. You’ll be able to see the cloud belts of Jupiter, perhaps even the great Red Spot. In addition, you’ll be able to see the moons of Jupiter as they orbit the giant planet. Saturn, with its beautiful rings, is easily visible at moderate power, as is Mercury. All you need to know is where to look. Most astronomy publications indicate where the planets are in the sky each month.

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Celestron 21052, 21071 manual Telescope Operation Astronomical Observing, Observing the Moon, Lunar Observing Hint
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21052, 21071 specifications

The Celestron 21052 and 21071 are standout models in the brand's renowned refractor telescope range, ideal for both novice astronomers and seasoned stargazers. The 70 AZ and 60 AZ options provide exceptional portability while still delivering impressive optical performance.

The Celestron 21052, featuring a 70mm aperture, is designed to capture bright and clear images of celestial objects. Its refractor design utilizes high-quality glass optics that reduce chromatic aberration, ensuring that colors are rendered accurately and clearly. With a focal length of 700mm, it offers a suitable balance of magnification and field of view, making it perfect for observing planets, star clusters, and even some of the brighter deep-sky objects.

The portable design of the 70 AZ model makes it easy to transport to various viewing locations. It comes with a sturdy, adjustable tripod that provides excellent stability during observations. Additionally, a smooth altazimuth mount allows for easyTracking of celestial objects as they move across the night sky. The telescope also includes a finder scope, which aids in locating objects quickly, enhancing the overall viewing experience.

The Celestron 21071, featuring a slightly smaller 60mm aperture, is a fantastic choice for beginners looking to get into astronomy without a hefty investment. Despite its compact size, the 60 AZ still offers great optical quality, making it possible to view the Moon's craters, Jupiter’s moons, and more with remarkable clarity. The 60 AZ is designed for quick setup and portability, making it ideal for impromptu stargazing sessions.

Both models come with a variety of accessories that enhance usability, including multiple eyepieces for different magnification levels and a star map to help users locate celestial objects. The telescopes are also compatible with a smartphone adapter, allowing users to capture images of their observations and share them with friends or social media.

Ultimately, the Celestron 21052 and 21071 refractor telescopes exemplify quality design and ease of use, making them excellent choices for anyone interested in exploring the night sky. With their user-friendly features and excellent optics, these telescopes provide a window to the wonders of the universe, encouraging a lifelong passion for astronomy.
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