More precise polar alignment is required for astrophotography and for use of the manual setting circles. If you have to wear your glasses while observing and cannot see the entire field of view, you may want to purchase additional eyepieces that have longer eye relief. sourceSelector:'' So the larger the telescope's aperture, the more it is capable of resolving. defaultImage: '', If this occurs, simply remove the slow-motion knobs and re-attach to the other side of the RA axis. defaultImage: '', At Orion, we are committed to sharing our knowledge and passion for astronomy and astrophotography with the amateur astronomy community. What causes dim or distorted images? Motor drives are usually equipped with a hand control that allows the telescope's tracking speed to be slightly increased or decreased, which is particularly critical when taking long-exposure astro-images. Takes me back to the 90s. The R.A. setting circle is scaled in hours, from 1 through 24, with small marks in between representing 10 minute increments (there are 60 minutes in 1 hour of R.A.). width: 160, it is possible to see way more the item product reviews in addition as rates. If it’s not, sweep the telescope carefully around the immediate vicinity until the object is found. Loosen the Dec. lock lever and rotate the telescope optical tube until it is parallel with the R.A. axis. Values of Dec. coordinates range from +90-deg to -90-deg. The Dec. slow-motion control is not needed for tracking, but may be required to center the object. defaultImage: '', If you don’t know your latitude, consult a geographical atlas to find it. The refractor telescope optical tube measures just 26" long including the dew shield, so it earns high marks for portability. Stars in the Northern Hemisphere appear to revolve around Polaris.. height: 160, height: 160, Because we sell direct, we can offer you tremendous value at a great price. That location is denoted by two numbers: its right ascension (R.A.) and declination (Dec.). Look through the polar finder again. Please send me email about sales, new products, and astronomy. So, the coordinates for the Orion Nebula listed in a star atlas will look like this: R.A. 5h 35.4m Dec. -5-deg 27’ That’s 5 hours and 35.4 minutes in right ascension, and -5 degrees and 27 arc-minutes in declination (there are 60 arc-minutes in 1 degree of declination). And when you're stargazing, Orion's telescope cases and covers, observing gear, red LED flashlights, astronomy books and star charts will make your observing sessions more convenient, comfortable and meaningful. The focal ratio of an optical system is the ratio of a telescope's focal length to its aperture. But that huge objective lens brings a level of clarity and detail which is hard to come by in cheaper refractor telescopes. }, { It provides an easy way to transport and store your telescope. Level the equatorial mount by adjusting the length of the three tripod legs. This warranty is for the benefit of the original retail purchaser only. 5. The highest practical limit is different from the often used "highest theoretical magnification" specification. Aligning the polar axis finder scope so that it will accurately point at the true north pole is a two-step procedure. The R.A. setting circle is labeled in hours, from “0” to “23” (military time). }, { It is a very intuitive technique that has been employed for hundreds of years by professional and amateur astronomers alike. sourceSelector:'' entityId: 103090, East or west: To point the telescope to the east or west, or in other directions, you rotate the telescope on its R.A. and Dec. axes. width: 160, For a … Since 1975 Orion Telescopes & Binoculars has been offering telescopes for sale direct to customers. }, { height: 90, The cast-metal 2" rack-and-pinion focuser accommodates either a 1.25" or 2" diagonal, so you can use optional 2" eyepieces for an even dreamier wide-field effect! Included are the 7.5mm and 12.5mm telescope eyepieces. }, { height: 90, }, { The steadiness of the air (the “seeing”) can also limit how much magnification an image can tolerate. At Orion, we are committed to sharing our knowledge and passion for astronomy and astrophotography with the amateur astronomy community. But as you become more experienced and your observing skills improve, you will be able to coax out more and more intricate details. You can see the disk of the giant planet and watch the ever-changing positions of its four largest moons, Io, Callisto, Europa, and Ganymede. If there is no lock ring the finder scope is focused by rotating the eyepiece. entityId: 99799, height: 160, Multiple layers of coatings are even more effective; the term "multi-coated" means one or more air-to-glass lens surface has multiple coatings. This will give you the widest possible field of view. Can the finder scope crosshairs be adjusted? width: 160, The AstroView 120ST is now assembled and should appear as pictured in Figure 1. }, { High-end short-tubes made with exotic glasses or with corrector lenses can handle higher power. Loosen the adjustment screws or pull on the tensioner (depending on the model) and rotate the finder scope tube in the bracket until the crosshairs are oriented the way you want. How do I Find Deep-sky Objects: Starhopping? Practice makes perfect. The Orion Shorty Barlow Lens doubles the power of any telescope eyepiece. You may find it convenient to remove both the counterweights and the telescope optical tube to do this. When the telescope is pointed north of the celestial equator, values of the Dec. setting circle are positive, while when the telescope is pointed south of the celestial equator, values of the Dec. setting circle are negative. Look through the polar finder at a distant object (during the day) and center it in the crosshairs. Orion 9005 AstroView 120ST Specs. width: 160, Referring to the manual is highly recommended. Telescopes on either very lightweight mounts or non tracking mounts (such as Dobsonians) are capable of only very short exposures such as lunar photographs. The 120ST has a well-baffled optical tube to ensure good contrast. As your eyes become dark-adapted, more stars will glimmer into view and you will be able to see fainter details in objects you view in your telescope. Heavy-duty and water-resistant, and fits the AstroView 6 EQ, AstroView 120ST EQ and SpaceProbe 130EQ. The focal length is an inherent specification of a mirror or lens and is one of the factors in determining resultant magnification for a telescope (along with the focal length of the eyepiece being used). Now look at your star chart and find the brightest star in the constellation that is near the object that you are trying to find. It is desirable to have a range of telescope eyepieces of different focal lengths to allow viewing over a range of magnifications. Binocular lenses and prisms are often coated with anti-reflective material to minimize light loss as light travels through the multiple optical surfaces of a typical binocular. defaultImage: '', 2. It provides the basic tracking function as well as fine control of the telescope position in any direction. When choosing a location for nighttime stargazing, make it as far away from city lights as possible. See our Learning Center articles: About General Astronomy width: 160, You can find astrophotography "how to" tips and share your best astronomy pictures here. Not limited to visual use, the fast f/5 optical system makes the AstroView 120ST an excellent refractor telescope to use for wide-field astrophotography in addition to observational astronomy. If, when looking through the finder scope, you notice that the image is fuzzy, you will need to focus the finder scope for your eyes. height: 90, Then point the telescope at a discrete object such as the top of a telephone pole or a street sign that is at least a quarter-mile away. Reflector telescopes use a pair of large and small mirrors to direct incoming light to the eyepiece. Posted by 1 day ago. Notice that the reticle pattern consists of a crosshair with a circle around the middle. Before cleaning with fluid and tissue, blow any loose particles off the lens with a blower bulb or compressed air. height: 160, As an Amazon Associate Love the Night Sky earns from qualifying purchases, present amazing views of deep-sky objects. sourceURL:'/catalog/community_content_viewer_placeholder.jsp?productId=99823&isPDP=true', Phillips-head screwdriver Refractor telescopes have long been touted as great optical instruments for studying the planets and Moon. Make sure you can comfortably lift and transport it, and that you have room indoors to store it. Alignment of the polar finder is best done during the day, before going out into the field at night. Everything you need, all in one kit! For more detailed information on this topic see our Learning Center article: What Will You See Through a Telescope Doing so will undo the polar alignment. Includes Ultra Brush Dust Remover, Dust Pro Compressed Air, Cleaning Fluid, 2 Booklets of Premium-Grade Lens Tissue, and Ten Cotton Swabs. }, { The larger the telescope, the more detail you will see. But anyone with the slightest technical bent will have no problem getting familiar with these models. The 120ST refractor telescope's achromatic objective lens has a short focal length of just 600mm (f/5) for exceptional rich-field performance. Dust cap defaultImage: '', “Seeing” refers to the steadiness of the Earth’s atmosphere at a given time. Great for families, young people, and folks who don't want to mess with equipment but just want to take a look. }, { }, { Then look again into the telescope’s eyepiece and see if it is still centered there too. height: 160, width: 160, If not, then look through the polar finder while rotating the mount about the R.A. axis. Weighs 36.5 lbs. }, { layers: '' width: 200, Refractor telescopes refract, or "bend" incoming light to a focus by means of an objective lens. defaultImage: '', height: 90, total (optical tube 8 lbs., 9 oz. The upper set of numbers apply to viewing in the Northern Hemisphere, while the numbers below them apply to viewing in the Southern Hemisphere. Atmospheric conditions vary significantly from night to night, even hour to hour . layers: '11_Intro-telescopetypes' Some are easy to use but are on the large or heavy side. width: 160, sourceURL:'/catalog/community_content_viewer_placeholder.jsp?productId=103153&isPDP=true', A good star to remember for this is Megrez (mag. You can find astrophotography "how to" tips and share your best astronomy pictures here. entityId: 103153, With short reflectors, “coma” comes into play: stars appear like “commas” or “seagulls” near the edge of the eyepiece field. layers: 'Artimg-LightPollution' For example, if your latitude is 35° North, set the pointer to +35. Also, seeing conditions are typically poor during the day. }, { defaultImage: '', Lowest useful magnification is the power at which the exit pupil becomes 7mm in diameter. This effect may not be noticeable at lower powers, but at higher powers the atmosphere will dramatically blur the object, reducing the quality of the image. report. entityType: 'product' Accessory tray bracket If you do not know the positions of the constellations in the night sky, you will need to get a planisphere to identify them. Directly south: The counterweight shaft should again be horizontal. height: 160, height: 160, Not limited to visual use, the fast f/5 optical system makes the AstroView 120ST an excellent refractor telescope to use for wide-field astrophotography in addition to observational astronomy. You can find astrophotography "how to" tips and share your best astronomy pictures here. entityId: 7828, defaultImage: '', entityType: 'product' height: 160, It is not uncommon for an observer to own five or more eyepieces. layers: '08711' The planets don’t stay put like stars do (they don’t have fixed R.A. and Dec. coordinates), so you will need to refer to the Orion Star Chart on our website. defaultImage: '', The planisphere gives an all-sky view and shows which constellations are visible on a given night at a given time. For the novice stargazer, buying a computer-controlled telescope with a small aperture puts a lot of money into the mechanical and database components of the telescope to locate objects that you can’t see with the optics of the telescope. entityId: 99798, entityId: 99825, Defocusing the image of a star slightly can help bring out its color. Using the finder scope, point the telescope at this star and center it on the crosshairs Next, look again at the star chart and find another suitably bright star near the bright star currently centered in the finder.