How Good is a 100 Dollar Telescope?

September 16, 2023 - If you are interested in astronomy and want to explore the wonders of the night sky, you might be wondering if you can get a decent telescope for under $100. The answer is yes, but with some caveats. In this article, we will review some of the best telescopes under $100, their features, pros and cons, and what you can expect to see with them.

What to Look for in a Telescope Under $100

Before we dive into the specific models, let's first go over some of the factors that you should consider when choosing a telescope under $100. These include:

Type: There are two main types of telescopes: refractors and reflectors. Refractors use lenses to bend light and form an image, while reflectors use mirrors to reflect light and form an image. Refractors are usually more compact, durable, and easy to use, but they can suffer from chromatic aberration, which is a distortion of colors at the edges of the image. Reflectors are usually more powerful, cheaper, and free from chromatic aberration, but they can require more maintenance, alignment, and collimation.
Aperture: The aperture is the diameter of the objective lens or mirror that collects light. The larger the aperture, the more light the telescope can gather, and the brighter and sharper the image will be. The aperture also determines the resolving power of the telescope, which is the ability to distinguish fine details and separate close objects. A larger aperture will allow you to see more details and fainter objects.
Focal length: The focal length is the distance from the objective lens or mirror to the focal point, where the image is formed. The longer the focal length, the larger the image will be, but also the narrower the field of view. The focal length also affects the magnification of the telescope, which is calculated by dividing the focal length of the telescope by the focal length of the eyepiece. A higher magnification will allow you to see more details, but also make the image dimmer and shakier.
Focal ratio: The focal ratio is the ratio of the focal length to the aperture. It is usually denoted by f/number, such as f/10. The lower the focal ratio, the faster the telescope, meaning it can collect more light in a shorter time. A lower focal ratio also means a wider field of view and a shorter tube. A higher focal ratio means a slower telescope, meaning it can collect less light in a longer time. A higher focal ratio also means a narrower field of view and a longer tube.
Mount: The mount is the device that supports and moves the telescope. There are two main types of mounts: altazimuth and equatorial. Altazimuth mounts allow you to move the telescope up and down (altitude) and left and right (azimuth). They are simple, easy to use, and suitable for terrestrial and casual astronomical observations. Equatorial mounts allow you to move the telescope along one axis parallel to Earth's rotation (right ascension) and one axis perpendicular to it (declination). They are more complex, require alignment with Polaris (the North Star), and suitable for tracking celestial objects across the sky.
Accessories: Some telescopes come with additional accessories that can enhance your viewing experience. These include eyepieces, finderscopes, Barlow lenses, filters, star diagonals, software, apps, books, etc.

The Best Telescopes Under $100

Now that you know what to look for in a telescope under $100, let's take a look at some of the best models available on the market.

1. Gskyer 70mm Travel Scope - The Gskyer 70mm Travel Scope is a refractor telescope with an aperture of 70mm (2.8 inches), a focal length of 400mm (15.7 inches), and a focal ratio of f/5.7. It comes with two eyepieces (25mm and 10mm), a 3x Barlow lens, a 5x24 finderscope, an aluminum tripod with an altazimuth mount, a smartphone adapter for capturing images and videos, a carry bag for portability, and software and app for learning astronomy. The Gskyer 70mm Travel Scope is one of the best telescopes under $100 for beginners and travelers who want a lightweight, compact, and easy-to-use telescope that can deliver clear views of bright objects such as the moon, planets, stars clusters, nebulae, etc.

Pros:

Affordable
Lightweight
Compact
Easy to use
Portable
Smartphone adapter included
Software and app included

Cons:

Low aperture
Low magnification
Chromatic aberration
Flimsy tripod
Plastic parts

2. Celestron 70mm Portable Refractor Telescope - The Celestron 70mm Portable Refractor Telescope is another refractor telescope with an aperture of 70mm (2.8 inches), a focal length of 400mm (15.7 inches), and a focal ratio of f/5.7. It comes with two eyepieces (20mm and 10mm), a 2x Barlow lens, a 5x24 finderscope, an aluminum tripod with an altazimuth mount, a backpack for portability, and software and app for learning astronomy. The Celestron 70mm Portable Refractor Telescope is similar to the Gskyer 70mm Travel Scope, but with a slightly different design and accessories. It is also a good choice for beginners and travelers who want a simple and convenient telescope that can offer decent views of bright objects such as the moon, planets, stars clusters, nebulae, etc.

Pros:

Affordable
Lightweight
Compact
Easy to use
Portable
Backpack included
Software and app included

Cons:

Low aperture
Low magnification
Chromatic aberration
Flimsy tripod
Plastic parts

3. Meade Instruments Infinity 70mm AZ Refractor Telescope - The Meade Instruments Infinity 70mm AZ Refractor Telescope is yet another refractor telescope with an aperture of 70mm (2.8 inches), a focal length of 700mm (27.6 inches), and a focal ratio of f/10. It comes with three eyepieces (26mm, 9mm, and 6.3mm), a 2x Barlow lens, a red dot finderscope, an aluminum tripod with an altazimuth mount, and software and app for learning astronomy. The Meade Instruments Infinity 70mm AZ Refractor Telescope is different from the previous two models in that it has a longer focal length and focal ratio, which means it can provide higher magnification and narrower field of view. It is also a good option for beginners who want a versatile telescope that can show them bright objects such as the moon, planets, stars clusters, nebulae, etc.

Pros:

Affordable
Lightweight
Compact
Easy to use
Three eyepieces included
Software and app included

Cons:

Low aperture
Chromatic aberration
Flimsy tripod
Plastic parts

4. Celestron PowerSeeker 70EQ Telescope - The Celestron PowerSeeker 70EQ Telescope is a refractor telescope with an aperture of 70mm (2.8 inches), a focal length of 700mm (27.6 inches), and a focal ratio of f/10. It comes with two eyepieces (20mm and 4mm), a 3x Barlow lens, a star diagonal, an aluminum tripod with an equatorial mount, and software and app for learning astronomy. The Celestron PowerSeeker 70EQ Telescope is similar to the Meade Instruments Infinity 70mm AZ Refractor Telescope in terms of optical specifications, but with a different mount and accessories. It is also a good choice for beginners who want to try an equatorial mount that can track celestial objects across the sky more easily. However, it also requires more setup and alignment than an altazimuth mount.

Pros:

Affordable
Lightweight
Compact
Easy to use
Equatorial mount included
Software and app included

Cons:

Low aperture
Chromatic aberration
Flimsy tripod
Plastic parts

5. National Geographic Compact Telescope 76/350 - The National Geographic Compact Telescope 76/350 is a reflector telescope with an aperture of 76mm (3 inches), a focal length of 350mm (13.8 inches), and a focal ratio of f/4.6. It comes with two eyepieces (20mm and 4mm), a moon filter, a star diagonal, a built-in compass, a Dobsonian base, and software and app for learning astronomy. The National Geographic Compact Telescope 76/350 is the only reflector telescope on our list, and the only one that does not require a tripod. Instead, it has a Dobsonian base that allows you to place it on any flat surface and move it manually. It is also the most affordable on our list, but also the most compact and portable. It is ideal for beginners who want to try a reflector telescope that can offer them brighter and sharper views of bright objects such as the moon, planets, stars clusters, nebulae, etc.

Pros: