Meade NG70-SM Instruction Manual - Page 13

Know your observing site: If possible, know the location where you will be observing. Pay attention to holes in the ground and other obstacles. Is it a location where wild animals, such as skunks, snakes, etc., may appear? Are there viewing obstructions such as tall trees, street lights, headlights and so forth? The best locations are dark locations, the darker the better. Deep space objects are easiest to see under dark skies. But it is still possible to observe even in a city. SPECIFICATIONS Optical tube focal length 700mm Objective lens diameter 70mm (2.8") Focal ratio f/10 Mounting type Altazimuth What do the specifications mean? Optical tube focal length is simply a measurement of the length of the optical tube. In other words, this is the distance light travels in the telescope before being brought to focus in you eyepiece. Your tube is 700mm long. the ratio, the faster exposure time is needed when a camera is hooked up to the telescope. Your telescope has 11 slower focal ratio at f/10. Sometimes, astronomers use focal reducers to make slow exposure telescopes have faster focal ratios. Altaz mounting simply means your telescope moves up and down (altitude or "alt"), and side to side, (azimuth or "az"). Other mounting configurations are available for other telescopes, such as equatorial mounting. Surf the Web and visit your local library: The internet contains a huge amount of astronomical information, both for children and adults. Check out astronomy books from your library. Look for star charts-these are available on a monthly basis in Astronomy and Sky and Telescope magazines. HAVE A GOOD TIME, ASTRONOMY IS FUN! Objective lens diameter is how big the lens is on your scope. Telescopes are always described by how large their objective lens is. Your telescope is 70mm or 2.8 inches. Other telescopes are 90mm, 8 inches, 16 inches, or even 3 feet in diameter. The Hubble Telescope's objective lens has a diameter of 2.4 meters (that's 7.8 feet across!). The focal ratio helps determine how fast the photographic speed of a telescope is. The lower the focal ratio number, the faster the exposure. f/5 is faster than f/10. The faster ASTRONOMY RESOURCES • The Meade 4M Community 27 Hubble, Irvine, CA 92618 • Astronomical League Executive Secretary 5675 Real del Norte, Las Cruces, NM 88012 • The Astronomical Society of the Pacific 390 Ashton Avenue, San Francisco, CA 94112 • The Planetary Society 65 North Catalina Avenue, Pasadena, CA 91106 • International Dark-Sky Association, Inc. 3225 N. First Avenue, Tucson, AZ 85719-2103 Looking at or near the Sun will cause irreversible damage to your eye. Do not point this telescope at or near the Sun. Do not look through the telescope as it is moving.