Choosing an Eyepiece

Fig. 12: To use Flip Barlow, rotate the flip control to the “down” position.

8.Plug in the handbox: Make sure that the computer control panel power switch is in the OFF position. Remove AutoStar from the packing materials and plug it into the HBX port.

Flip the Power Switch on the computer control panel to the ON position. The copyright message lights on AutoStar’s LCD display. See Fig. 11b.

9.Accept the Sun Warning: Press the key prompted by AutoStar to accept the Sun warning.

A telescope’s eyepiece magnifies the image formed by the telescope’s main optics. Each eye- piece has a focal length, expressed in millimeters, or “mm.” The smaller the focal length, the higher the magnification. For example, an eyepiece with a focal length of 9mm has a higher magnification than an eyepiece with a focal length of 25mm.

Your telescope comes supplied with two standard eyepieces.

Low power eyepieces offer a wide field of view, bright, high-contrast images, and excellent eye relief during long observing sessions. To find an object with a telescope, always start with a low power eyepiece. When the object is located and centered in the eyepiece, you may wish to switch to a higher power eyepiece to enlarge the image as much as practical for prevailing see- ing conditions.

Note: Seeing conditions vary widely from night-to-night and site-to-site. Turbulence in the air, even on an apparently clear night, can distort images. If an image appears fuzzy and ill-defined, back off to a lower power eyepiece for a more well- resolved image (Fig. 14a and 14b, page 17).

The power, or magnification of a telescope is determined by the focal length of the telescope and the focal length of the eyepiece being used. To calculate eyepiece power, divide the tele- scope's focal length by the eyepiece's focal length. E.g., Assume you are using a 25mm eye- piece. The focal length of the ETX-80AT is 400mm (see SPECIFICATIONS, page 35).

Telescope Focal Length ÷ Eyepiece Focal Length = Magnification

400mm ÷ 25mm = 16

The eyepiece power, or magnification is therefore 14x. However, your telescope also contains

a built-in 2 times Barlow. This means you also have to multiply magnification figure by two.

16 x 2 = 32

So your telescope has a 32 times magnification.

Manual Operation of the Telescope without AutoStar

If you wish to observe a distant land object, such as a mountain top or a bird, you can observe by merely pointing the telescope and looking through the eyepiece. Assemble the telescope, loosen the horizontal and vertical locks (13 and 14, Fig. 1), and turn the telescope towards the object you wish to observe. Sight along the top of the tube until you find the object. When the object appears in the eyepiece, focus the image using the by turning the focus knob (15, Fig. 1). Rotate the knob clockwise to focus on distant objects and counterclockwise to focus on nearby objects.

You can also observe stars and objects in the night sky using this method, but note that objects begin to slowly drift across the eyepiece field. This motion is caused by the rotation of the Earth.

As you become familiar with AutoStar operation, you can counteract the drift using the automatic tracking feature in the Setup menu (see TO TRACK AN OBJECT AUTOMATICAL- LY, page 16), or by using AutoStar's GO TO capabilities (see GO TO SATURN, page 18).

Sight along the top of the telescope’s tube to line up objects for viewing in the eyepiece. See Fig. 13.

Fig. 13: Sight along the top of the optical tube.

ETX-80AT-TC specifications

The Meade ETX-80AT-TC is a sophisticated yet user-friendly telescope that caters to both novice astronomers and seasoned stargazers. This compact telescope is particularly praised for its portability, making it an ideal choice for those who wish to explore the night sky without the burden of heavy equipment.

One of the standout features of the ETX-80AT-TC is its 80mm aperture, which delivers impressive light-gathering capabilities. This allows users to observe a wide range of celestial objects, from the craters on the Moon to distant galaxies. The telescope’s Achromatic refractor design minimizes chromatic aberration, ensuring sharp and clear images across the field of view.

The Meade ETX-80AT-TC is equipped with the AutoStar computer control system, which enhances the observational experience significantly. This technology allows users to locate and track thousands of celestial objects with ease. With a simple push of a button, the telescope can automatically find and track planets, stars, and deep-sky objects, making it perfect for those who are new to astronomy and may find manual navigation challenging.

Additionally, the telescope features a built-in Solar System tour that animates a journey through the solar system, providing educational insights about the celestial bodies in our neighborhood. It is operated via a user-friendly handheld controller with a numeric keypad and an LCD display, making navigation intuitive even for beginners.

The ETX-80AT-TC also includes a durable and lightweight design, with an integrated tabletop tripod for stable viewing. It can be easily set up and taken down, allowing for spontaneous stargazing adventures. The telescope is compatible with various Meade accessories, including additional eyepieces and filters, which further enhance the observing experience.

In terms of mechanics, the ETX-80AT-TC boasts smooth, slow-motion manual controls for fine adjustments and a flip mirror for easy switching between visual and photographic modes. Whether capturing breathtaking astrophotos or enjoying the stars visually, this telescope delivers versatility and quality.

Overall, the Meade ETX-80AT-TC stands out with its thoughtful combination of features, technology, and portability, making it an excellent choice for anyone looking to explore the wonders of the night sky. Whether you are a budding astronomer or a more experienced enthusiast, this telescope provides ample opportunities for wonder and discovery under the stars.