How to Choose My First Telescope

Choosing A Telescope

There’s no single “best” telescope, which keeps things interesting. Choices depend on factors like price, complexity, size, and quality.

Most stargazers end up with multiple telescopes, each with its strengths. Small, non-computerized telescopes are perfect for quick backyard moon and planet viewing. Some are easily portable, making them convenient for regular use. Larger, computer-controlled telescopes are heavier and break into sections, requiring more effort to set up.

450 X magnification or more?

Avoid telescopes advertised by magnification, as they are likely low-quality. Never purchase from malls, department stores, warehouse clubs, or TV. These tend to be disappointing and a waste of money. Be cautious with Craigslist; most listings are likely subpar. We’ll discuss where to buy later, for now, let’s explore your options.

Refractor, Reflector or Catadioptric

See Telescope Basics for more complete descriptions.

Refractor: This is what most people think of when they hear the word “telescope”. Modern glass has vastly increased this designs desirability but only at the higher end of the price scale. A quality refractor is usually on every astronomers wish list.
Advantages: Potential for the best images, no obstruction in light path.

Disadvantages: The most expensive of the three designs per inch of aperture (often by a large margin). Some secondary color “(chromatic aberration)” is visible in all but the best units. Large aperture instruments are massive.

Reflector: Invented by Sir Isaac Newton to fix the refractors issues with chromatic aberration. Uses a parabolic mirror instead of a lens to focus light.
Advantages: Most economical of the three designs per inch of aperture (especially those on Dobsonian mounts).
Disadvantages: Secondary obstruction results in some loss of contrast. Can require occasional collimation (alignment) of optics.

Catadioptric: Schmidt-Cassegrain, Maksutov-Cassegrain, Schmidt-Newtonian are all Catadioptric designs that use both mirrors and lenses to fold the optical path back onto itself resulting in a compact design. The Schmidt-Cassegrain telescope is the most common variant and is referred to as an “SCT.”
Advantages: Most compact per inch of aperture of the three designs.
Disadvantages: Images are typically the worst of the three designs.

Size (Aperture)

The larger the aperture the more light you can gather and the dimmer the object you can see. If you plan on looking at the faintest objects like dim nebula and distant galaxies far from the typical suburban light pollution, then you want to consider looking for the largest aperture telescope you can afford. However, if you are concerned about the size and weight, then huge isn’t for you.

Focal Ratio (f/number)

When comparing scopes of equal aperture, the smaller the f/number, the wider the field of view. Focal ratios of f/4 to f/6 are best for low power wide field observing. Focal ratios of f/10 to f/15 are better suited to higher power lunar, planetary, and binary star observing. Medium f/7 to f/9 focal ratios are a good compromise to allow both fairly well.

Telescope Mounts

The telescope’s mount is crucial for your experience. There are two main types: Alt-azimuth and Equatorial.

Alt-azimuth requires constant adjustments due to Earth’s rotation. The Dobsonian, a reflector telescope, is a popular example without motors or computers, making it a good choice for beginners and experienced users alike.

Equatorial mounts align with Earth’s rotation axis for easier tracking. They were the first to feature “clock” drives, and later, computer systems for precise targeting.

Go-To or not to Go-To

Even budget telescope mounts now come with “Go-To” technology, driven by a computer and motors for precise targeting. This may seem ideal, but it’s complex. Initial alignment requires knowledge of brighter stars’ names and locations, aided by star charts or astronomy apps. Don’t assume it’s easy just because it’s computer-driven; it takes effort to set up correctly.

Advanced mounts offer Go-To with GPS and self-aligning cameras but come at a cost, requiring time to master.  Some stargazers prefer manual “star hopping” to locate objects, finding it more satisfying than relying on a computer. It’s a different, rewarding experience.

For mounts without Go-To, you can add Digital Setting Circles, often used on large Dobsonian telescopes, assisting in finding deep sky objects, sometimes called “push-to” scopes.

Eyepieces

Eyepieces are crucial for a telescope’s field of view and magnification. Quality matters, as even a fine lens or mirror won’t perform well with a subpar eyepiece. Three or four carefully selected eyepieces are sufficient.

Eyepieces vary widely in price ($25 to $800) due to complexity. Balance price, performance, and quality. Expect to pay more for wider fields of view, better eye relief, and higher-quality glass. Don’t buy a $700 eyepiece for a $300 telescope when an $80 one can work just as well. If you wear glasses, look for eyepieces with good eye relief.

Don’t focus solely on high magnifications; they’re rarely usable due to sky conditions and can make objects appear dimmer. Lower power, wider field eyepieces are used most of the time.

Astrophotography

A beginner getting into astrophotography is like wanting to enter the Indy 500 without knowing how to drive. It’s a big endeavor, requiring a substantial investment. While smartphone attachments can capture basic images, true astrophotography is much more complex and expensive. It involves specialized equipment, software, and significant time investment, especially in light-polluted areas. If you’re still determined, thorough research and possibly building an observatory in dark skies are crucial. It’s a serious commitment.

Video Astronomy

Light pollution limits suburban stargazing, but the NAA has an observatory with video astronomy that shows deep sky wonders in color. You can also watch live sessions on Night Skies Network where amateur astronomers broadcast their live viewing sessions using Mallincam cameras. You can get a better idea of what is possible by watching and asking questions.
Video astronomy is simpler than astrophotography, but it’s not for beginners. Video astronomy uses a special camera, in place of an eyepiece, connected to a screen. It’s better than our eyes – with sensitivity and exposure control, so fainter objects can be seen in light-polluted skies.

Video astronomy requires a special camera, a sturdy mount, and a short focal length telescope. Sometimes a computer is needed. Low-priced cameras work for the moon, but colorful deep sky objects need more expensive equipment.

How large of a telescope do you really need?

A smaller backyard telescope wins by default over a big one you didn’t bother to set up. While some argue you can never have a telescope that’s too big, it doesn’t always make the larger one better. Large scopes can’t do wide fields of view, which is important for large objects. That’s why many stargazers have more than one telescope.
The telescope’s diameter also affects its resolving power, but this assumes perfect optics and seeing conditions. Interestingly, in bad seeing, a small telescope can sometimes resolve more than a large one because it catches less turbulence.

Making Decisions

When budgeting for a telescope, a good starting point is around $400 for an entry-level option. An 8″ Dobsonian telescope is a great choice, offering a reasonably large aperture, one eyepiece, a quality red dot finder, and a sturdy mount. It’s affordable per inch of aperture, easy to set up, and provides consistent optics. With an f/5.9 focal ratio, it’s versatile for wide-field and high-power observations.
Our observatories showcase two 6″ versions of this telescope, allowing visitors to test drive it. If you’re in the area, you’re encouraged to try it out.
For those with higher budgets, options like the 14″ Celestron telescope, which costs around $10,000, provide a glimpse of what’s possible, but there are even more expensive choices.
Consider portability as well: How heavy are the parts, and how easy is it to set up and store? Telescopes that are too large or heavy tend to be used less frequently.