BUYING YOUR FIRST VISUAL TELESCOPE
There’s a vast universe of sights to see in the night sky. While unassisted stargazing can be a lot of fun, a telescope is definitely the best way to get the most out of your viewing experience. If you’re new to the world of astronomy, there are a few things you need to consider when purchasing your very first visual telescope.
Firstly, you should be aware of the three basic types of telescopes, which are refractors (which use lenses to bend light into focus,) reflectors (which use mirrors to reflect light into focus,) and catadioptric or compound scopes (which use a combination of lenses and mirrors.) For more information on this subject, check out our video explaining the basic types of telescopes.
Generally speaking, the basic function of every telescope design is to collect light to make a faraway object more visible. The various scope designs, whether they use lenses, mirrors, or some combination of these, are simply different methods to achieve this goal. Each of these types has its own benefits and considerations, including portability, durability, maintenance, ease-of-use, and budget.
The term “aperture,” as it typically applies to telescopes, is the size of a telescope’s main optical element, whether that be a lens or a mirror. As a rule, larger aperture scopes are typically the best way to view widefield and deep sky objects like galaxies and nebulae. At the same time, smaller scopes are great for observing solar system objects like the moon, Jupiter, and Saturn.
Since aperture is tied to the size of the scope in this way, a lower aperture telescope will usually cost less than a higher aperture scope of the same type.
Another important aspect of telescopes to consider is “maximum magnification,” which represents the highest degree to which you can enlarge the image before the view starts to become blurry.
In most cases the maximum magnification of a telescope is 50x per inch of your scope’s aperture. The larger the aperture, the larger the useful image you can see. Following this 50x magnification rule, a 2” aperture scope will have a maximum useful magnification of 100x, whereas a 10” aperture scope will have a maximum useful magnification of 500x.
In order to reach the magnification you need, you will have to attach an eyepiece to your telescope. The lower the rating of the eyepiece in millimeters, the more it will magnify your scope’s view. Since certain magnifications are better for viewing certain objects, it’s usually a good idea to have a handful of eyepieces with different powers to let you view a wide array of objects.
Just be sure that your desired magnification does not exceed your scope’s maximum magnification, since pushing a small scope beyond its limit just to see a faint object won’t actually help you see it any better. If you’re struggling to get the useful magnification you want with a small scope, you might need to upgrade to a larger aperture scope.
A good selection of starting eyepieces that should work with a wide range of scopes would be, a 9mm, a 20mm, and a 32mm eyepiece.
It would also be a good idea to pick up a 2x barlow, as this can be used to double the magnification of an eyepiece. These should give you a good range of available powers, but you might possibly need a different set of eyepieces depending on your telescope or what you want to see.
CHOOSING A TELESCOPE
So, with these basics in mind, what are some good telescope choices for beginners?
If you’re on a budget and just want to do basic nearby solar system observing of the moon and the planets, a small refractor is a great value. A quality entry-level refractor scope will usually be in the range of 3-5 inches of aperture with packages starting at around $100. These are highly portable and rugged, and can be used for both nighttime and daytime viewing.
If you’d prefer to look at deep sky objects like galaxies and nebulae, a great option is a Dobsonian reflector with an aperture of 6-10 inches. These scopes are both very powerful and great for beginners. They are one of the simplest types of telescopes to use, as simply pointing the optical tube in the direction you want to look is enough to move the scope’s view. On top of that, they are also very affordable, with quality options as low as $200.
If you’re looking for a scope with even higher optical quality, a catadioptric telescope, makes for a great investment. Packing a lot of optical power into a compact package, a compound scope is a great pick-up-and-go scope for observing in a variety of locations and situations.
Depending on the scope you choose, you may also need to consider what kind of mount you need for it. You’ll need to make sure that you have a mount with enough load capacity to hold up your telescope, along with all of your accessories.
However, there are many telescope package available which include a mount that will support the scope it comes with, along with more than enough accessories to get you started.
These are just a handful of things to consider when purchasing your first telescope for visual observing. Ultimately, what you choose is up to you and the type of observing experience you want. If you have any questions or want to know more, you can contact the experienced staff at OPT. We’ll be glad to share our expert knowledge with you and help you get the visual scope that’s right for you. Happy observing!