Meade Infinity 80mm User Manual - Page 15

times. The 9mm eyepiece magnifies objects 66.7 times. If you obtain other eyepieces, you can calculate how much magnification they have with your telescope. Just divide the focal length of the telescope by the focal length of the eyepiece. Focal Length of the Telescope ÷ Focal Length of the Eyepiece = Magnification Look at the specifications. For the Infinity 90, you will see that the focal length of this scope is 600mm. Let's say that you have obtained a 13mm eyepiece. You can tell that what the focal length of your eyepiece is as it is always printed on the side of an eyepiece. Divide: 600 ÷ 13, which equals 46.15. Round this off to the nearest whole number and the new 13mm eyepiece magnifies objects 46 times. A great accessory for your telescope is a Barlow lens If you use a Barlow lens with one of your eyepieces, it doubles the magnification of your eyepiece. Other types of Barlows can triple or further increase the power of an eyepiece. To find out how much the magnification is when you use a Barlow, multiply your eyepiece's magnification by two. Eyepiece's magnification x 2 = Magnification with a 2X Barlow lens For the Infinity 90 the 26mm low-power eyepiece magnifies an object 23 times. Multiply 23 by 2 and you get 46 times magnification with a Barlow. It's worth repeating: Keep in mind that a bright, clear, but smaller image is more interesting than a larger, dimmer, fuzzy one. Using too high a power eyepiece is one of the most common mistakes made by new astronomers. So don't think that higher magnification is necessarily better-quite often the best view is with lower magnification value! TAKING CARE OF YOUR TELESCOPE Your telescope is a precision optical instru- 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. ment designed for a lifetime of reward- ing viewing. It will rarely, if ever, require factory servicing or maintenance. 13 Follow these guidelines to keep your telescope in the best condition: • Avoid cleaning the telescope's lenses. A little dust on the front surface of the telescope's correcting lens will not cause loss of image quality. • When absolutely necessary, dust on the front lens should be removed with very gentle strokes of a camel hair brush or blown off with an ear syringe (available at most pharmacies). JOIN AN ASTRONOMY CLUB, ATTEND A STAR PARTY One of the best ways to increase your knowledge of astronomy is to join an astronomy club. Check your local newspaper, school, library, or telescope dealer/ store to find out if there's a club in your area. Many groups also hold regularly scheduled Star Parties at which you can check out and observe with many different telescopes and other pieces of astronomical equipment. Magazines such as Sky and Telescope and Astronomy print schedules for many popular Star Parties around the United States and Canada.