Telescopes which one to buy

Admittedly, there is a bewildering array of equipment available; however, we can divide all those variations into just three basic types. The second type we will consider, invented by Isaac Newton, are known as reflectors because they utilise mirrors instead of lenses to achieve an enlarged sky view.

The final type of telescope design involves mirrors with a hole in the middle. We call telescopes of this type Cassegrains. With this basic separation into groups established, we can review the benefits and compromises of each. Read our guide to the best beginner telescopes , or if portability is your thing, find out which models made our list of the best travel telescopes. The most popular type of telescope, refractors have many appealing qualities. They tend to be lightweight, easy to set up and intuitive to use, give sharp views and require practically no maintenance.

Interchangeable eyepieces offer varying magnifications and increase the range of viewable objects. Good portability allows for trips to enjoy darker skies away from light polluted areas. Or in basic terms, bigger is better.

In this respect refractors have limits. Very large lenses are prohibitively expensive and quite unmanageable for amateurs. Refracting telescopes available to the amateur today therefore tend to be available in apertures between 60 — mm.

Within that range we find inexpensive models with a single front lens, up to telescopes with multiple lenses that provide a sharper more natural view, at a premium price point. The quality of the optics in the telescope, determined predominantly by their cost, will have a significant bearing on the quality of the views, and the cheap refractors that tend to be popular at electrical goods and camera shops are often disappointing.

Generally speaking, smaller refractors less than 90mm diameter are best suited for wider views of the night sky, which might include star clusters like the famous Pleiades , M Although some detail and moons may be seen when observing Jupiter and Saturn, in either case the planet itself will appear quite small and very bright in the view.

Some brighter galaxies and nebulae may be visible under good skies, and with experience it becomes easier to pick out the interesting objects. However, larger refractors mm in diameter and upwards can really open up the skies, and under reasonably dark skies there will be hundreds of deep-sky objects that can be viewed including galaxies, globular clusters of stars and bright nebulae.

Lunar views too should be sharp with good definition in craters and rille features, as the larger optics enable the telescope to reveal more detail. There is no doubt that a decent refractor, on a sturdy mount or tripod, can provide a thrilling stargazing experience, and whet the appetite for further sessions for many years. Reflecting telescopes have an open tube at the front and a round mirror inside the bottom of the tube, called the primary mirror. Light entering the tube is reflected back inside the tube onto a much smaller angled secondary mirror, and then out through the side of the telescope near the top end, which is where the interchangeable eyepiece goes.

This design allows for much larger apertures than are possible with refractors, and amateur reflectors are available right up to a whopping mm diameter. There are two ways of using reflectors. Smaller models up to 12 inches or so can be used on tripod-style mounts similar to those used for refractors. A popular alternative option, though, is to mount the telescope tube onto a rotating base that sits on the floor. This can be turned freely around, while the telescope can pivot up and down and thus be pointed anywhere in the sky.

Telescopes mounted in this way are known as Dobsonians and, compared penny for penny, offer the most cost-effective and rewarding views of the deep sky. In fact the views offered by a relatively modest reflector can compare favourably with those offered by expensive refractors.

However, they can be heavy, bulky items that are awkward to take outside and bring back in, or to transport to darker sites, and they can take up a lot of room when not in use. The largest Dobsonian models, although collapsible into manageable components, may even require the use of a stepladder when viewing objects high overhead! Examples of an equatorial mount include center-balanced equatorial mount CEM that have an equatorial wedge to tilt the fork arms toward the North Pole and German equatorial mounts that come with many refractors.

Eyepieces are a whole venture of their own because of the amount of magnifications available to you and what you can do with them! Most telescopes include additional eyepieces to provide more details of the objects you want to see. Sometimes you might notice that some include a Barlow lens, which doubles the magnification of whatever eyepiece you attach it to. Feeling overwhelmed with the choices available? Check out our guide put together by OPT experts on how to find the best eyepieces for you!

Welcome to the world of enhancing your telescope buying experience! If you're buying a telescope kit , most come with all the accessories you need to get started. If you are building your own setup, you may want to look into different filters, hand controllers for computerized mounts, or focusers.

Check out our list of the best telescope accessories here to get a head start. We hope that this guide was useful in helping you get a start with buying a telescope. We proudly carry a wide variety of brands for your convenience. Please call us if you'd like some extra help!

Whether you're a total beginner or an experienced amateur, this helpful guide compares 12 popular telescope designs to help you decide which telescope to buy!

July 21, 2 Comments. March 11, 0 Comments. January 20, 0 Comments. January 06, 2 Comments. We will match any online price that we confirm as valid. The item must be the identical item, brand name, size, weight, color, quantity and model number. It must be in stock at the time of Price Match for us to make a guarantee. No rainchecks will be issued for items out of stock at OPTcorp. We do not price match competitors if they are out of stock.

Browse brands. Share article. APOs are also particularly good for wide-field astrophotography. Apochromats used to be extremely expensive, but prices have come down significantly in recent years. The cheaper but still excellent! An ED refractor is now a plausible choice for a beginner who wants a rugged, portable, highly versatile telescope and is willing to accept the limited image brightness and resolution that are inevitable consequences of small aperture.

The second type of telescope, the reflector , uses a mirror to gather and focus light. Its most common form is the Newtonian reflector invented by Isaac Newton , with a specially curved concave dish-shaped primary mirror at the bottom end of the telescope.

Near the top, a small, flat, diagonal secondary mirror directs the light from the primary to the side of the tube, where it's met by a conveniently placed eyepiece.

If you want the most aperture for your money, the reflector is the scope for you. When well made and maintained, a reflector can provide sharp, contrasty images of all manner of celestial objects at a small fraction of the cost of an equal-aperture refractor. Newtonians have two additional important advantages. And the eyepiece is at the top of the tube, meaning that the pivot point is well below your head. That allows them to be used with low tripods or, in the case of the popular Dobsonian design, with no tripod at all.

In general, a Newtonian on a Dobsonian mount delivers by far the brightest and most detailed images possible per dollar. Newtonians do require occasional maintenance. Unlike a refractor's solidly mounted lens, a reflector's mirrors can get out of alignment and hence need periodic collimation adjustment to ensure peak performance, particularly if the telescope is moved frequently.

The mirrors of the average Newtonian may not require tweaking for months at a time. But for those not mechanically inclined, having to collimate a Newtonian reflector even occasionally may be frustrating. Then there's the third type of telescope, the catadioptric or compound telescope. These were invented in the s out of a desire to marry the best characteristics of refractors and reflectors: they employ both lenses and mirrors to form an image.

The greatest appeal of these instruments is that, in their commonly encountered forms the Schmidt-Cassegrain and Maksutov-Cassegrain , they are very compact. Their tubes are just two to three times as long as wide, an arrangement allowed by "optical folding" of the light. The smaller tube can use a lighter and thus more manageable mounting. The upshot is that you can obtain a large-aperture, long-focus telescope that's very transportable.

But here too there are caveats. That means that they are unable to produce genuinely wide, low-power fields of view. Like the Newtonian, the Schmidt-Cassegrain telescope needs occasional optical collimation that lessens its appeal to those disinclined to tinker.

In terms of cost, aperture for aperture, the catadioptric lies midway between the reflector and the refractor. Like a Newtonian, the popular forms of compound telescopes have a secondary mirror in the light path, and this slightly degrades performance for high-magnification lunar and planetary observing.

Even so, when well made, a Schmidt-Cassegrain or Maksutov will deliver very fine images of a wide variety of celestial objects. If you live in an area where dew occurs which is almost everywhere , some sort of tube extension is a must to prevent dew from forming on the exposed corrector plate at the front of the tube. Many people in humid climates also use electric dew heaters. Catadioptrics also take longer than any other design to cool down to the temperature of the night air, which is necessary to produce pristine high-power images.

So unless you can leave your scope outside to pre-cool, catadioptrics are a poor choice for quick, casual looks at the planets. Low-quality mounts are by far the most common problem with budget-priced telescopes. That can make observing painful at best and impossible at worst. And when you let go, the aim must not jump to one side. All telescope mounts fit into a few broad categories. The oldest and simplest design is the manually adjusted altitude-azimuth mount, often referred to as an alt-az.

These work like the pan-and-tilt heads on photo tripods, moving the scope up-down in altitude and left-right in azimuth. In fact, robust photo tripods work fine for small telescopes at low and medium magnifications.

If you intend to use a small telescope for casual sky viewing or daytime use say, birdwatching , you'll find an alt-az mounts preferable because of its simplicity, compactness, and light weight. Alt-az mounts designed for high-power use often have finely threaded slow-motion controls that enable the scope to be moved smoothly by tiny amounts.

The Dobsonian mount dispenses with the tripod and places the pan-tilt head directly on the ground. Dobsonian mounts are typically built of wood or particleboard, and the large, stable bearings are usually constructed with Teflon.

This results in a very sturdy, low-cost mount that ideally glides smoothly about both axes with fingertip control. A Newtonian reflector mounted in this fashion is not only extremely easy to set up and use, but very good value, too. That makes it easy to track celestial objects as they drift across the sky — or more precisely, appear to move as Earth rotates beneath you.

This can be done easily with brief twists of a slow-motion knob, or you can equip an equatorial mount with a motor to achieve automatic tracking. Motorized tracking is especially valuable at high power. Equatorial mounts suffer from two main drawbacks.

Despite that, their tracking capability made them essential for almost all serious amateur telescopes until the advent of the motorized Dobsonian mount and computerized alt-az Go To mount. That can be a big time-saver, especially in light-polluted settings, where there are few reference stars to aid you in finding the objects yourself.

Go To mounts can also follow objects across the sky just by recalculating the position every second or so and making the necessary corrections. That makes it possible to combine the mechanical and ergonomic benefits of alt-az mounts with automatic tracking, something not possible before the computer age. There are a number of cautions to bear in mind when it comes to Go To technology. First, most Go To mounts need to be initialized so that they know the time and location as well as their orientation.

Some of the priciest models can do this completely automatically, but most entry-level Go To scopes do the initialization by asking you to point them at specific stars.