User manual BUSHNELL REFRACTOR EQUATORIAL MOUNT

[. . . ] The second star can really be any star in the sky other than our sun and the North Star. You can pick a star from a constellation that is in the sky and use a particular star in it. You will not only have to be able to identify it, but in Step 5 you will need to be able to center it in the telescope. If you want to use your equatorial mount, you'll need to be able to do this. [. . . ] This diagram illustrates these axis's where the telescope can move. 5 The Different Lenses There are many different lenses to know about on a refractor telescope. If you try different combinations other than what is listed in the next few pages, you will not be able to see out of your telescope clearly. It is generally shorter than the 20mm eyepiece. 20mm Eyepiece This is the low-powered eyepiece. It is generally taller than the 4mm eyepiece The Barlow Lens This piece multiplies the magnification by generally 2 to 3 times. The Barlow Lens 5 BARLOW Most of the time it will say 2X or 3X on the side of it. Every once in a while it will even have a different number. The Erector Lens All telescopes turn the image upside down. This piece can "erect" the image. The Erector Lens 4 ERECTOR Erecting the image is only available on Refractor telescopes. Erecting Lenses generally multiply the magnification by 1. 5 times. The Penta Mirror All telescopes make the image appear to move in the opposite direction as you are turning it from right to left. The Penta Mirror corrects this and allows you to look down into the telescope instead of having to look from behind. The Penta Mirror It multiplies the magnification by 2 times. 3 The Diagonal Mirror The Diagonal Mirror allows you to look down into the telescope instead of having to look from behind. It does not correct the right to left viewing. The Diagonal Mirror This piece offers no additional magnification. As well, most all Refractor telescopes come with either the Penta Mirror or the Diagonal Mirror but never with both. 3 6 Figuring the Magnification Magnification is generally referred to as "power". Figuring the power on a Refractor telescope sometimes can be tricky because of all of the different combinations possible. Below I'll go into the different combinations and how to figure each magnification. To figure magnification you must first know the basic formula for determining it. It is: Focal Length in mm ÷ Eyepiece in mm = Magnification (Power) Example: A telescope that has a 700mm focal length that has a 20mm eyepiece in it has 35 power or magnification. 700 (focal length) ÷ 20 (eyepiece in mm) = 35 (power) If you have in a 3X Barlow lens also then multiply the answer by 3. 700 (focal length) ÷ 20 (eyepiece in mm) = 35 (power) 35 (power) X 3 (Barlow Lens) = 105 (power) Since the Penta Mirror doubles the magnification, then you would further multiply the answer by 2 if you added to the lens example. 700 (focal length) ÷ 20 (eyepiece in mm) = 35 (power) 35 (power) X 3 (Barlow Lens) = 105 (power) 105 (power) X 2 (Penta Mirror) = 210 (power) Finally, there is one Bushnell telescope (78-9470) that offers a Zoom Lens that magnifies from 25 ­ 75 times. It can ONLY be used in conjunction with the Penta Mirror and therefore offers actual magnifications of 50 ­ 150. (The Penta Mirror once again doubles the magnification. ) It also erects the image so you need no other lenses with it. 1 Zoom Eyepiece/Assembly Lens Combinations 7 The different lenses offer many combinations. Using the previous definitions you should be able to determine the effect each lens will have on the viewing. [. . . ] If the finderscope is not the crosshair type but instead the dot kind, get the dot directly in the middle of the object then tighten the finderscope best as possible. Note: The finderscope just like the telescope turns the image upside down also. Know that finderscopes sometimes have a red dot in them as opposed to crosshairs. Sometimes they adjust with thumbscrews on the outside of the mounting bracket and sometimes they have actual fine adjustment knobs on the finderscope itself. Regardless, you will need to determine how to adjust them yourself using common sense and if you have it, the instruction manual. 11 898 7 23 22 21 20 19 18 190-200-210-220-230240-250-260-270-280-290 You can generally leave the Counterweight all the way down and tighten the screw so it won't move. Get everything at right angles. [. . . ]