New to Astronomy
Those of us who share a passion for the night sky understand the desire to own a telescope. The decision to buy a telescope is not without peril. Since most inexpensive telescopes have so many issues, it is common for people to buy a telescope, struggle with it for several nights and then retire it to the closet. It does not have to be this way, but too often it is. The fact is, most inexpensive telescopes are junk and many expensive telescopes have issues caused by mass production, poor design or bad quality control. The internet is of little help since most self-professed experts have never made a telescope or really understand how optics are fabricated. There is plenty of bad advice out there.
When I was quite young, my parents wanted to foster my budding interest in science so they bought me a small, 60 mm refractor. With its wobbly mount and poor optics, I could not use it for much so I gave up. Lucky for me a friend in school made me aware of suppliers of telescope parts and suggested I actually make my own. I learned all I could, got to know telescope makers personally and began grinding and polishing glass myself. The first telescope I made, routinely outperformed larger and more expensive telescopes, making me quite proud.
First, let's review the types of telescopes you may choose from. There are three main types of telescopes:
Those with lenses (Refractors, below left)
Those with mirrors (Reflectors, below center)
- Those with a combination of elements that use mirrors and lenses (Catadioptric Telescopes, below right)
The Refractor: A refractor has a lens in the front and you view through the rear. This makes it easy to use as you simply point the tube at the object - easy. Refractors are more expensive than reflectors because they have several curved optical surfaces that need to be precisely figured. They are more expensive but the best of these have higher contrast, show extreme clarity, have sealed tubes, never need alignment, are more portable and are lighter. Now a note of caution, when we discuss refractors, we are referring to high quality apochromatic refractors not the less expensive imports and especially not department store telescopes. Avoid these and avoid frustration.
Stellarvue has two kinds of refractors, doublets with two glass lens elements in front and triplets with three glass lens elements in front. The diagram above shows a triplet refractor.
If you purchase a good wide field refractor, you will probably keep it for many reasons. It has certain advantages over a larger reflector:
A. For astronomy, the biggest advantage is its enormously wide field of view. Using a wide field eyepiece, Stellarvue 70 - 80 mm telescopes become a "Richest Field Telescope." That is a telescope that shows an enormous amount of sky. Larger telescopes cannot show this. For this reason, over the past twenty years, relatively few Stellarvue 80 mm telescopes have been sold on the used market despite the fact that we have made thousands! Even when customers upgrade to a larger Stellarvue refractor or a huge reflector, they keep the wide field refractor for seeing the entire Andromeda Galaxy, sweeping around the Milky Way with thousands of stars in full view. There is nothing like using a Richest Field Telescope under a dark sky.
B. A small, wide field telescope is easy to set up and easy to take with you. Our 70 mm and 80 mm refractors come in an airline carry-on case. So, you check the tripod and carry the telescope on the plane, keeping it safe. Once you get there it is easy to set up. You may even take it with you on the trail.
C. It can be used as a terrestrial or birding telescope by adding an erecting prism. The telescope is small and the eyepiece conveniently placed for using it as the ultimate terrestrial telescope.
Current models of Stellarvue telescopes are all Apochromatic. This means that they are extremely sharp, are free of annoying color fringe, have the highest contrast and provide as sharp a view as high end birding telescope costing over $2,000!
The Reflector: The most common and least expensive type of reflector has a mirror in the back and an eyepiece that sticks out of the side of the tube. This is known as a Newtonian Reflector because it was invented by Sir Issac Newton. Newtonian reflectors are much less expensive than refractors. They are easier to make as they have only one curved surface. This telescope has an open tube and air currents inside can distort the image. Reflectors are larger, heavier and require periodic alignment. On the upside, they gather a lot of light. They are often called light buckets. So objects will appear quite bright in them. For this reason, you may eventually end up with a a large reflector and use it to study distant galaxies and nebulae, also known as "faint fuzzies".
There is a significant difference in performance between a mass produced reflector and a custom made reflector using a high end mirror that is hand figured by a master optician. As an example, we purchased a mass produced import 16" f-4.5 mirror and built it into a reflector. Optical performance was very poor. Resolution was compromised and contrast was lacking. We then purchased a 16" f-4 mirror from Lockwood Custom Optics. We mounted it in the same optical tube assembly. Even though it was a faster optic (more difficult to produce), the star test was perfect, contrast was high and resolution was outstanding. Here again, I am including this to help people avoid disappointment. High end optics are more expensive but you will see much, much more.
Catadioptric telescopes: These are the short stubby telescopes you see at star parties. They have a lot of very complicated names like Schmidt-Cassegrain, Maksutov Cassegrain, etc. The advantage of the design is that they are relative short and reasonably portable. The disadvantages are they have a very small field of view and they lack the contrast seen in high end refractors since light is reflected back and forth and there is a large secondary mirror in the middle of the light path. Smaller apo refractors have the advantage of highly accurate optics that provide razor sharp images, no central obstruction, a wide field of view combined with the ability to increase power to 100X per inch under very steady skies.
My advice to those interested in buying a telescope is to slow down. Life can be a long and enriching experience if you savor each step along the way. Here is what I recommend:
1. Start by learning the night sky. You can download an inexpensive planetarium program like Star Walk on your portable device and this will show you in real time the sky above and help you learn the constellations. This program will point out where the planets and deep sky objects are above you. Now you are ready to go to step 2.
2. Try binoculars. With your planetarium program you can now use binoculars or a wide field telescope to get a closer look at objects like the moon, nebulae and star clusters. Get out to a dark sky location. You will be amazed at how many stars are above and how awesome open clusters and the Milky Way appear in your binoculars. Most people have binoculars or can borrow them. The advantage is, they are readily available. The disadvantage is you are limited to low power.
3. Get a very good wide field refractor: Having learned the night sky and many constellations, you are now ready to get your first telescope. The advantage of a good wide field telescope over binoculars is, you can select different eyepieces to boost the power and see much more! You'll barely make out the moons of Jupiter with a good pair of binoculars but you will never see surface features on the planets or the rings of Saturn.
Remember: a telescope that is used most often is the best telescope. This is a portable scope that is easy to set up and easy to use but only if it has:
A. Very good optics and
B. A good stable and smooth mount and tripod.
A wide field telescope will make it easier to locate objects than a large telescope. Getting a wide field refractor first is easiest to transition into. It is also something you will probably keep even if you move on to something larger someday for the reasons outlined below.
4. Which Stellarvue telescopes are recommended for beginners? This is a good question and it all depends on what you want to do with it. For example, if you want a telescope to be used for both daytime and night time visual observing the SV80 Access is a great choice. Not only is this our least expensive telescope, it is also small, lightweight and compact it makes a great birding telescope. The SV80 Access can be made into a complete system (telescope, mount, tripod, star diagonal and eyepieces) for about $1100.00. In 2019 we will introduce a complete system with a very durable American wood tripod.
Perhaps you want to use the telescope primarily for viewing a night sky. The SV102 Access is a great choice since it is still very reasonably priced but it will show more than an 80 mm telescope. With its four inch objective you will reach deeper with more light gathering power so galaxies and nebulae are brighter and with its higher resolution, you will see more detail on the planets.
You may decide you will want to get involved in Astro-photography. If this is the case you may want to consider buying one of our Premier Apo Triplet Refractors. These telescopes have the highest optical accuracy and correction.
We created the Access line of telescopes to get people started right with good optics and stable mechanics. Access series telescopes make great visual telescope systems and they are a great way to get started in what may prove to be a lifelong endeavor!
5. So, you want to start taking pictures through your telescope? If you think that someday you will want to try astro-photography, I suggest you first enjoy the visual performance of your telescope for at least a year. This will allow you to learn the night sky and get to know the various objects in space. Learning how to take images can be a frustrating experience even with the best of equipment, so make sure you are ready before jumping off into the deep end. But when you are ready, make sure you get a highly accurate equatorial mount. While you may want to start off using your DSLR, eventually you will want to invest in a ccd camera dedicated to imaging the night sky. Astro imaging is not as easy as it looks. There is a long learning curve. You can't rush it. Make sure you are ready and properly outfitted before you take the plunge.
We will provide more information on imaging soon. Look for our "New to Astro-photography" page coming soon.
We also have an abbreviated Telescope-Astronomy Glossary to help you become more familiar with common terms used while discovering more about telescopes and Astronomy. We hope this helps you and inspires you to learn more.