Good Telescope To See Planets

Telescope-FAQ

How can I pick the best telescope for my needs?

With all of the language and technical information surrounding telescopes, selecting the ideal one can be difficult, particularly for a beginner. There are hundreds of possibilities available, each with a plethora of unique combinations, settings, and costs to match.

The majority of models these days have generally rather decent quality because telescopes have become much better in recent years. Nevertheless, some solutions are better than others, and we’ve made every effort to feature only the finest in our guide. 

The optical quality a telescope offers is arguably the most crucial consideration when selecting one. Additionally, consider what kind of aperture you require and if you need a larger, more powerful model or one that is more portable. Starter telescopes are an excellent choice if you’re new to the field.

You’ll also need to think about your setup if you plan to attempt astrophotography, where you’re observing from, and specific things you want to observe in order to get the best views of the night sky. 

To ensure you receive precisely what you purchased, and because many respectable telescope sellers offer warranties with your purchase, we would urge you to stick with them when purchasing your scope. Businesses that sell astronomical equipment also frequently have the greatest prices on their goods and consultants on hand to assist you in selecting the finest option.

Here’s a summary of the various kinds of telescopes available, along with our recommendation for the top model.

Which kinds of telescopes are available?

Reflector, refractor, and catadioptric telescopes are the three primary categories of telescopes.

Refractors use an objective lens, while reflectors use a primary mirror to collect and focus light. A lens with the same diameter and a primary mirror characterizes catadioptric. There are subtypes of all three of these telescope types, with differences in their designs. To deflect light at right angles to the eyepiece from the top of the telescope, the simplest reflector telescopes, for instance, feature a smaller, secondary mirror in addition to their larger, Newtonian primary mirror. 

As we’ve already indicated, there are a ton of excellent (and reasonably priced!) telescopes available these days. Which kind should you choose? We believe the best value in aperture is provided by Newtonian reflector telescopes mounted on a basic, undriven alt-azimuth mount, also referred to as a “Dobsonian.”

On the other hand, a Dobsonian telescope can be the best option if you want to explore the night sky “the old-fashioned way.” They have no bells and whistles, so you’ll need to arm yourself with a star map so you can make sense of stargazing. Dobsonians capture a great deal of light and have a high enough resolution capability to provide amazing views of astronomical objects. 

If you decide to buy a dobsonian telescope with an aperture larger than 6 inches, you’ll need to think about storage space because these telescopes are typically quite big and imposing. A garage or garden shed could be the finest choice.

Newtonian or refractor telescopes become substantially more expensive when an equatorial or digital mount is included. Newtonian telescopes are available with a variety of computerized mounts, including German equatorial (Go To), Dobsonians (push-to or Go To), and single time-mounted (tracking or Go To). For example, the cost of a computerized push-to Dobsonian will be around double that of a manual model of the same aperture, while the cost of a Go-To will be nearly four times that of a manual model. 

It is possible for a quality Newtonian on a German equatorial mount to cost up to 10 times as much as one on a manual mount!

If you enjoy gadgets and value portability, convenience, and ease of use, you might be interested in a computerized mount for a short focal length refractor up to 4 inches or a catadioptric (Schmidt- or Maksutov-Cassegrain) up to 5 inches. With the help of these adaptable, highly magnified telescopes, you can see incredible details on the moon and planets. 

Because achromatic refractors with short focal lengths are unable to focus all light wavelengths to a single point, they usually exhibit some false color around the margins of brilliant objects, such as the moon. Because refractors are so simple to operate and maintain, most users are content to put up with this disadvantage; still, the Maksutov is your best bet if you’re looking for a clear, high-contrast vision without any artificial color.

Apochromatic refractors provide the greatest views of the night sky. They eliminate false color by focusing all light wavelengths to as close to a single point as feasible using specialized glass objectives. It is noteworthy, however, that the cost of apochromats is around four times that of achromats of equal size. 

How do telescopes with refractors operate?

Refractors function by refracting, or bending, the light they collect so that you can see your celestial objective. The refractor is simple to assemble and works well for viewing the moon and planets. It uses lenses to gather and concentrate light to create a picture, which is then magnified with an eyepiece.

With the main objective lens at one end and a star diagonal with a threaded eyepiece at the other, the refractor’s design is somewhat simple. Due to their low maintenance requirements and ease of use, refractors are frequently chosen by beginning astronomers as their primary instrument. Refractors are typically mounted on a basic alt-azimuth mount, which moves up and down as well as side to side to find the intended target. 

Because these telescopes are simple to operate, they are also inexpensive to purchase because they are inexpensive to produce, at least for entry-level models.

The drawback is that the price of the refractor increases with aperture size. Sadly, this also implies that a basic refractor is the easiest item to fake in mail-order catalogs and other untrustworthy sellers; thus, care needs to be taken while making this kind of telescope purchase. 

Refractors are the best equipment to use while observing solar system objects like the moon and planets because they are very good at producing highly magnified and high contrast images. The best refractors will give you decent views of astronomical objects and typically have an aperture of two inches (60 mm) or more. If you want a bigger aperture, a 3 to 4-inch (80 mm – 90 mm) would be ideal.

A refractor’s disadvantage is that it might experience color fringing, sometimes referred to as chromatic aberration. The moon, Venus, and Jupiter are examples of brilliant objects that typically have a colored halo surrounding them when a single lens is unable to focus all the colors emitted from the object at the same spot. Many refractors are made as achromatic or APO chromatic (also known as Extra Dispersion (ED) telescopes) in order to lessen this issue.

Because of its affordability and higher efficiency compared to the apochromatic refractor, amateur astronomers frequently go for an achromatic telescope. You will probably receive a persistent degree of purple fringing around some targets, even if you go with the more expensive achromatic. 

This degree of color fringing won’t significantly detract from your observing experience, unless you’re an experienced skywatcher and can afford to upgrade to the more costly apochromatic, which corrects for such an effect by utilizing exotic glass for the lenses. You will be astounded by the views you can see through these superb telescopes if you choose to go with the more costly alternative. However, be advised that certain apochromatics may not have a tripod; you will need to purchase one separately in addition to any other necessary items. 

What is the operation of a reflector telescope?

The Newtonian and Dobsonian reflector telescopes are the two most popular varieties. Both of these tools work by reflecting light off of mirrors to produce an image of the object you are looking at.

The base of the tube has a curved light-collecting mirror that is part of the Newtonian telescope. After striking this mirror, light is reflected back to the front of the tube, where it is mirrored by a smaller, flat mirror that faces 45 degrees, allowing the viewer to see the item of their choice. 

The Newtonian reflector is commonly mounted on alt-azimuth mounts, but it’s not surprising that it’s also commonly attached to an equatorial mount, which enables the telescope to track the sky’s revolution while staying aligned with the celestial pole of your hemisphere. Because it can be used for astrophotography and is versatile enough to observe a large variety of astronomical objectives, this reflector is a favorite among amateur astronomers. A big aperture can be purchased for less money with Newtonians; for example, an eight-inch (203.2 mm) reflector would be less expensive than a refractor with the same aperture, giving you far more value for your money.

Telescopes with Newtonian reflectors do need some upkeep. To make sure that the mirrors are correctly reflecting light, they must be frequently positioned. It can also be necessary to repaint the mirrors as they corrode with time. Choose a Newtonian reflector telescope with a mirror coating if you decide to use one. As a result, the mirrors will last longer and require less maintenance.

An equatorial mount can be difficult for some astronomy novices to put up and operate; in this case, the Dobsonian telescope is useful. Because they use an alt-azimuth mount, these telescopes offer the capabilities of a reflector without the complications that come with an equatorial mount. When looking at astronomical objects, Dobsonians are quite easy to use and can be dragged into orientation with ease. GoTo, or computerized Dobsonians and Newtonians, which slew objects for you using an internal motor, are available on the market but are more expensive if you’re not comfortable operating your telescope. See our guide on “What are Dobsonian telescopes?” for more information on these.

How do you operate a catadioptric telescope?

The catadioptric, which combines the best features of two types of telescopes—the reflector and the refractor—is a fantastic tool for taking a wide range of celestial subjects and is ideal for astrophotography. In addition, the catadioptric’s sealed optics require little to no maintenance, and its lightweight form makes it far more portable than other types of telescopes. Selecting a catadioptric has only one significant drawback: most of them might be pricey. On the other hand, purchasing one of these instruments on a tight budget is not unheard of; you simply need to be careful to compare prices. 

The catadioptric uses both lenses and mirrors to provide superior and high-definition images, whereas refractors utilize lenses and reflectors use mirrors to create and magnify an image. Light from your selected target is passed through a lens during your observations, correcting or reducing aberration that distorts the view that is eventually seen via the eyepiece. This light is then reflected by curved primary mirrors onto a secondary mirror, which is ultimately reflected into your eyes. There are two varieties of catadioptric telescopes: the Maksutov-Cassegrain and the Schmidt-Cassegrain.

The Maksutov-Cassegrain, or “Mak,” as it is affectionately nicknamed, corrects the optical issue that reflectors encounter, namely the “coma” aberration effect, which can cause objects to appear deformed and as though they have a tail. The combined action of a meniscus lens (which is ‘weakly negative’) and a spherical mirror lessens or eliminates this effect. Chromatic aberration, commonly known as color fringing, is a distortion that results in an undesired purple or blue border around brilliant objects in the night sky. Maksutov is also skilled at correcting for this distortion.

Its short optical tube contains a system that lets you aim for things with increased magnification, like the moon, planets, and double stars. Furthermore, both the Schmidt-Cassegrain and this kind of catadioptric telescope are widely available and come with a GoTo system if you have trouble finding objects and navigating the night sky.

You can perform broad observations of stars and planets with the Schmidt-Cassegrain, the other most popular type of catadioptric, which has capabilities comparable to those of the Maksutov. Corrector lenses can also be used to increase the telescope’s field of view, providing stunning vistas of an even greater variety of astronomical objects. 

What is a finder scope?

A finder scope is a secondary telescope mounted on your primary telescope that has modest power (low magnification). The majority of main telescopes have a narrow field of view, which means that looking through one will only show you a small section of the sky. With a larger field of view, your finder scope helps you aim your telescope at the thing you want to focus on, reducing the amount of time you need to search for and adjust your target. 

Place your subject in the center of the finder scope’s frame; the subject’s center will usually be indicated by a dot or crosshairs. This is also where your subject will be centered when you gaze through the eyepiece of your telescope.

There are two primary varieties of finder scopes that are available if you need to buy one separately, even though many telescope packages come with one. Two views are available: a straight-through view and a right-angled view. Because of where their eyepieces are located, whether you use a refractor or catadioptric, you’ll generally want a straight-through view and a right-angle finder if you use a Newtonian reflector telescope. Certain finder scopes will also have a magnified lens; if you require precise accuracy, you might want one with a narrower field of view and a higher magnification. 

Additionally, the terms “inverted” and “erect image” will be encountered. In the latter case, the finder sight is equipped with a corrective prism that flips the image both “around” (from left to right) and “right way up” (from top to bottom). Certain finder scopes lack a corrective prism, which causes you to view an image that is either upside down or backwards, which can be confusing and make finding subjects more challenging, particularly if you’re just getting started. 

What do aperture, magnification, and focal length signify on a telescope?

It’s time to debunk the jargon myths surrounding telescope terms. The larger the aperture of a telescope, the more light it collects, allowing for a better view of different subjects. For example, a camera with a 200mm aperture can collect four times more light than a camera with a 100mm aperture. Under ideal circumstances, stars with a magnitude of +11.8 may be seen through a 100mm telescope, and stars with a magnitude of +13.3 can be seen via a 200mm telescope. A 100mm telescope will divide a binary star into 1.5 arcseconds and resolve a lunar crater three kilometers across, while a 200mm telescope will resolve a crater only 1.5 kilometers across and binary stars only 0.6 arcseconds apart. The resolution of the camera is limited by its optical properties and the stability of the Earth’s atmosphere. The size of a telescope is determined by dividing the focal length of the telescope by the focal length of the eye. For example, a 100mm telescope with a focal length of f/8 (eight times the telescope aperture) has a focal length of 800mm and a magnification of 80x (1/800) when used with a 10mm eyepiece.

The usefulness of magnification in any telescope is determined by the combination of its aperture and focal length, along with the focal length of the eyepiece. Using a low magnification (capturing a wide field of view) will result in wasted light because the ‘exit pupil’ of the eyepiece will be larger than the size of your dark-adapted eye’s pupil. In dimly lit environments, the average adult pupil tends to expand to approximately 7 mm in diameter. Consequently, the exit pupil of an eyepiece should ideally be 7 mm or smaller, ensuring that all the light collected by the telescope, particularly when observing faint objects, can be captured. The exit pupil can be determined by dividing the telescope’s aperture by the magnification provided by a specific eyepiece.

Magnification: what is the mechanism behind telescope eyepieces?

The function of the eyepiece is to magnify the light collected by the telescope’s primary mirror or objective lens. All binoculars have a focal length in millimeters; the smaller the value, the greater the magnification. Divide the eyepiece’s focal length by its length to find the magnification that a specific eyepiece provides. For example, a 1000mm focal length telescope with a 10mm eyepiece (1000 divided by 10 = 100) will provide 100x magnification when using a 100mm refractor at f/10 or a 200mm Newtonian refractor at f/5.

While any telescope can achieve high magnifications using short focal length eyepieces, there comes a point where increasing magnification actually leads to a decline in image quality instead of enhancing it. Because the limited amount of light is spread over a greater surface when an object is bigger, its brightness falls. Furthermore, increasing magnification intensifies the visibility of atmospheric turbulence, making high magnifications suitable only when the viewing conditions are favorable. Finally, high magnification is only achievable with telescopes that are driven. Otherwise, the object will rapidly move out of the field of view.

The maximum power of your eye should be twice the magnification of your camera in millimeters; for example, 200x for a 100mm telescope, 400x for a 200mm telescope, etc. A good lens with low, medium, and high magnifications of around 50x, 100x, and 200x. Using a 100mm f/10 telescope as an example, these eyepieces are available in 20mm, 10mm, and 5mm focal lengths. We believe these particular eyepieces are from the Plossl brand. The field of view of a 20mm eyepiece is approximately 1 degree (0.8 square degrees of field), making it ideal for measuring depth and locating objects. A 10mm eyepiece can only see half of the moon’s diameter, hence its field of vision is just 25% that of a 20mm eyepiece. Because a 5mm lens is so large, its field of view is just one-sixteenth that of a 20mm lens. It’s limited to use while viewing is authorized.

How We Evaluate the Discover a good telescope to see planets with clear, sharp views. Perfect for beginners and stargazers looking for affordability and great performance!

We make sure to put every telescope tube through a comprehensive examination to measure all factors, so you can be sure you’re getting honest, current recommendations on the best telescopes on Space. Each telescope is evaluated on a variety of factors, from construction to design, optical instrument function, and performance in the field. The camera is tested extensively. This ensures a fair review is given based on the camera’s price, category, and intended use. For example, a 10-inch Dobsonian refrigerator, even if it’s best in its class, shouldn’t be compared to a 2.76-inch refrigerator. We also determine if the camera comes with a good eyepiece and camera. We also offer additional gear recommendations that may be useful for a better experience. Buying guide, meaning our reviews and purchases are fair and transparent. We serve our users with their favorite brands. Like this guide, we update these throughout the year, so they’re always worth checking out. You can also shop for high-end weather-watching gear from a variety of retailers. Best binoculars? They are, and we have a guide to goggles at Best Buy. We’ve also picked out our favorite cameras under $500, the best beginner cameras, and the best kids’ cameras—not to mention the best cameras for adults if you’re looking for those specifically.