Refractor Telescope Manual
Renita Lukins
Product manuals and software for current Meade and Coronado products can be found under the Support tab on their product pages. If you are looking for manuals for older Meade and Coronado products, you can download them from the links below.
Meade Instruments is acknowledged as one of the most innovative and dynamic companies in the telescope market. Known for its groundbreaking telescopic designs, Meade has introduced dozens of improvements over...
Explore the Universe with our PolarLink 102EQ Refractor telescope for an incredible experience. This telescope can view the planets, moon, star clusters and brighter deep sky objects like the Orion Nebula and Andromeda Galaxy at night.
This line of telescope features an aluminum German Equatorial mount with slow motion control on Right Ascension and Declination axis. Navigate the night sky with the two slow motion cable for smooth and accurate pointing. This allows the observer to easily track any celestial object and land object with ease. The mount also features a Vixen style dovetail received which accepts any optical tube that has a Vixen dovetail.
This telescope has enough aperture, a usable finderscope and focuser, and the eyepieces are adequate (not two but THREE of them!). The mount and tripod are unfortunately wobbly, but, with a half gallon milk jug filled with sand strapped under the tripod stabilizer / accessory tray, that can be minimized somewhat to make this usable. And, this telescope has a dovetail mount so it can be put on a different, strong mount in the future. And eyepieces can be upgraded too.
While the lens on this achromat does exhibit some chromatic aberration (color from not all wavelengths focusing at the same point) this is a known issue for less expensive refractors, and is really only an issue on brighter objects like the Moon, Jupiter and Venus.
Choosing the perfect telescope can be a challenge, especially as a beginner, considering the amount of jargon and technical knowledge that surrounds them. There are hundreds of options to choose from, with multitudes of different configurations, settings, and of course at a wide range of prices.
The quality of telescopes has drastically improved in recent years, so most models' quality is usually pretty good these days. That said, there are better options than others, and we've endeavoured to only include the very best in this guide.
Probably the most important factor in choosing a telescope is the optical quality it provides. You'll also want to think about what aperture you need and whether you need a more portable model or a larger, more powerful one. Beginner telescopes are a brilliant option if you're just starting out in the field.
In order to get the best possible views of the night sky, you'll also need to consider where you're observing from, what objects you'd like to see in particular, your setup if you're going to attempt astrophotography, and more.
We'd advise you to stick to reputable telescope dealers to buy your scope from, as you'll be sure to get exactly what you've ordered, and many will provide a warranty with your purchase. Astronomical equipment businesses also tend to offer the best deals on their products, and have advisors on hand to help you make the right decision for you.
Reflectors have a main mirror to gather and focus light, whereas refractors have an objective lens. Catadioptrics have a main mirror, and a lens of the same diameter. All three of these types of telescopes have 'sub-types' which vary by design. For example, the most basic reflector telescopes have a Newtonian design, which means they have a main mirror and a smaller, secondary one to divert the light at right angles to the eyepiece from the top of the telescope.
As we've mentioned above, nowadays, you're spoilt for choice when it comes to quality (and relatively affordable!) telescopes. So, which type should you opt for? We think Newtonian reflector telescopes on a simple undriven alt-azimuth mount (known as a 'Dobsonian') offer the best value in terms of aperture.
However, if you are interested in learning your way around the night sky 'the old fashioned way', then a Dobsonian telescope might be the way to go. They don't come with any bells and whistles, so you'll need to arm yourself with a star map to make sense of stargazing. Dobsonians collect a lot of light, and they have enough resolving power to deliver breathtaking views of celestial objects. Dobsonian telescopes over 6 inches in aperture tend to be pretty large and imposing, so you'll need to consider where it can be stored if you purchase one. A garden shed or garage might be the best option.
If you add an equatorial or computerized mount, Newtonian or refractor telescopes become much more expensive. You can find several types of computerized mounts for Newtonian telescopes: Dobsonians (push-to or GoTo), single time-mounted (tracking or GoTo) and German equatorial (GoTo). For reference, for a computerized push-to Dobsonian, you'll be looking at spending about twice as much than for a manual model of the same aperture, while a GoTo will set you back almost four times the price of its manual counterpart. A premium Newtonian on a German equatorial mount can be as much as ten times more expensive than one on a manual mount!
If ease of use, portability and convenience are high on your requirements, and you like gadgets, then a short focal length refractor of up to 4 inches or a catadioptric (Schmidt- or Maksutov-Cassegrain) up to 5 inches on a computerized mount may well fit the bill. These are versatile telescopes with high magnification which enables you to observe amazing details on the moon and planets.
Achromatic refractors with short focal lengths typically display a degree of false color around the edges of bright objects like the moon because they can't focus all wavelengths of light to a precise point. Most users are happy to accept this drawback because refractors are so easy to use and care for; however, if you're after a clean, high-contrast view without false color, the Maksutov is the best option here.
The best views of the night sky are obtained through apochromatic refractors. Using special glass objectives, they focus all wavelengths of light to as near a single point as possible and are free of false color. It is worth noting though that apochromats cost around four times as much as equivalent-sized achromats.
The refractor has a fairly straightforward design, with a main objective lens at one end and a star diagonal with a threaded eyepiece at the other. Being intuitive to use, the refractor is often a popular instrument for novice astronomers, given their low maintenance. Refractors are usually affixed to a simple alt-azimuth mount, that slews from side to side and up and down to locate a desired target. Being easy to use means these telescopes are also simple to manufacture (at least for novice models) and, therefore, cheaper to buy.
The downside is that the higher the aperture, the more expensive the refractor gets. Unfortunately, this means that a basic refractor is also the number one target to replicate in mail-order catalogs and other non-reputable vendors, so caution must be exercised when purchasing this type of telescope.
Refractors are particularly good at giving highly magnified and high contrast images and, because of this, are ideal instruments to use when looking at solar system targets such as the moon and the planets. The best refractors usually have an aperture of 2 inches (60mm) or more and will provide you with reasonable views of astronomical objects. A 3 to 4-inch (80 mm - 90 mm) would be best suited if you're looking for a larger aperture.
The drawback of a refractor is that it can suffer from chromatic aberration, also known as color fringing. When a single lens doesn't focus all the colors emitted from a target object at the same point, bright objects such as the moon, Venus or Jupiter usually have a colored halo around them. To reduce this problem, many refractors are manufactured as achromatic or APOchromatic (also known as Extra Dispersion (ED) telescopes).
The achromatic refractor is cheaper than the apochromatic refractor and, combined with its efficiency, is often the type of telescope that novice astronomers go for. Even if you choose the more expensive achromatic, you'll likely get a stubborn degree of purple fringing around some targets.
Newtonian reflector telescopes do require some maintenance. The mirrors must be aligned periodically to ensure that they are reflecting light properly. The mirrors can also become tarnished over time, so they may need to be repainted. If you choose a Newtonian reflector telescope, select one with a protective mirror coating. This will help extend the mirrors' life and make them easier to maintain.
Packed into its short optical tube is a system that allows you to target higher magnification objects such as the planets, moon and double stars. Additionally, if you struggle to find objects and your way around the night sky, then both this type of catadioptric telescope and the Schmidt-Cassegrain can be found in abundance and equipped with a GoTo system.
The other most common kind of catadioptric, the Schmidt-Cassegrain, offers similar capabilities to the Maksutov and will allow you to make general observations of planetary targets and stars. It is also possible to expand the telescope's field of view with the help of corrector lenses, enabling exquisite views of an even wider selection of astronomical targets.
A finder scope is a low-power (low magnification) telescope that sits on your main telescope. Your main telescope will typically have a narrow field of view, meaning you'll see only a little portion of the sky when you look through it. Your finder scope, with a wider field of view, assists you in pointing your telescope to your desired subject, making it easy to hone in on your target with minimal searching and repositioning.
Center your subject in the finder scope's frame; there are usually crosshairs or a dot so you know when it's central. Now when you look through your telescope's eyepiece, your subject will be centered here too.
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