What to Look for When Buying a Telescope
What to Look for When Buying a Telescope

What to Look for When Buying a Telescope

What to Look for When Buying a Telescope: Have you ever looked up at the night sky, filled with stars, and thought about getting a telescope, but then got stuck wondering which one to choose? You’re not alone. Picking the right telescope can be really confusing, especially with so many options out there. But don’t worry, that’s exactly why we’re here! We’ll take you step by step through everything you need to think about before buying a telescope. Whether you’re just starting out or looking to upgrade, we’ll help you figure out what matters most to you in a telescope.

When you’re a looking to buy a telescope, there are several factors to consider to ensure you get a model that meets your needs and expectations. Here’s a guide to help you make an informed decision:

Types of Telescopes

There are several types of telescopes, each with its advantages and disadvantages. The choice of telescope depends on your observing preferences, budget, and ease of use. Here are the main types and suitable users for each:

  1. Refractor Telescopes
    • Design: Uses lenses to gather and focus light.
    • Pros:
      • Low maintenance.
      • Good for lunar, planetary, and binary star observations.
    • Cons:
      • Can be expensive for larger apertures.
      • Chromatic aberration (color fringing) in some designs.
    • Suitable Users:
      • Beginners interested in planetary and lunar observation.
      • Those who prefer low-maintenance optics.
    • Price Range: $100 to several thousand dollars.
    • Aperture Size: Commonly ranges from 60mm to 150mm for consumer models.
  2. Reflector Telescopes
    • Design: Uses mirrors to gather and focus light.
    • Pros:
      • Typically more affordable for larger apertures.
      • Excellent for deep-sky observations.
    • Cons:
      • Requires occasional collimation (mirror alignment).
      • Bulkier compared to refractors of similar aperture.
    • Suitable Users:
      • Beginners interested in deep-sky objects.
      • Users willing to perform basic maintenance like collimation.
    • Price Range: $100 to several thousand dollars.
    • Aperture Size: Typically starts around 114mm and can go up to 406mm for larger, more advanced models.
  3. Compound Telescopes (Catadioptric)
    • Design: Combines lenses and mirrors.
    • Types: Schmidt-Cassegrain, Maksutov-Cassegrain.
    • Pros:
      • Compact and portable.
      • Versatile for various types of observation.
    • Cons:
      • Can be more expensive than reflectors or refractors of similar aperture.
    • Suitable Users:
      • Those seeking a versatile telescope for different types of observations.
      • Users who want a balance between portability and performance.
    • Price Range: $300 to several thousand dollars.
    • Aperture Size: Commonly ranges from 90mm to 300mm for consumer models.
  4. Dobsonian Telescopes
    • Design: A type of reflector telescope mounted on a simple, sturdy base.
    • Pros:
      • Excellent aperture for the price.
      • Simple design with minimal setup.
    • Cons:
      • Bulky and not as easily portable.
    • Suitable Users:
      • Beginners interested in deep-sky observations. Also Read: What Color is Pluto?
      • Those on a budget looking for a large aperture.
    • Price Range: $200 to several thousand dollars.
    • Aperture Size: Popular sizes are 6 inches (150mm) to 12 inches (300mm) and even larger.
  5. Computerized Telescopes (GoTo Telescopes)
    • Design: Can be refractors, reflectors, or compound telescopes with computerized mounts.
    • Pros:
      • Automatically locates celestial objects.
      • Helps beginners find and track objects easily.
    • Cons:
      • More expensive.
      • Requires some learning for setup and operation.
    • Suitable Users:
      • Beginners who want assistance in locating celestial objects.
      • Those interested in astrophotography.
    • Price Range: $400 to several thousand dollars.
    • Aperture Size: Similar to other types, with common consumer sizes ranging from 80mm to 300mm.
  6. Solar Telescopes
    • Design: Specialized telescopes for observing the Sun.
    • Pros:
      • Equipped with solar filters for safe solar viewing.
    • Cons:
      • Limited to solar observation.
    • Suitable Users:
      • Users specifically interested in solar astronomy.
    • Price Range: $200 to several thousand dollars, depending on features.
    • Aperture Size: Commonly smaller apertures, often below 100mm, specifically designed for solar observation.

Also Read: Find Solar Declination Based on Your Zip Code | Solar Declination Calculator

What You Need to Know Before Buying a Telescope | For All Levels
Exploring the Deep Sky with a Telescope

Aperture Size

The aperture is the diameter of the telescope’s main optical component (lens or mirror). Larger apertures collect more light, which is crucial for seeing faint objects. As a rule, choose the largest aperture you can afford and manage. Here’s how aperture size influences a telescope’s capabilities:

  1. Light Gathering Power:
    • The primary purpose of the aperture is to gather light. The larger the aperture, the more light the telescope can collect. This is crucial for astronomy since it directly affects the ability to see faint objects in the night sky. A telescope with a larger aperture will generally provide brighter and more detailed views than a smaller one.
  2. Resolution:
    • Resolution refers to the telescope’s ability to distinguish fine details and separate closely spaced objects, like the bands on Jupiter or the separation of binary stars. A larger aperture generally offers better resolution, allowing you to see finer details.
  3. Magnification Potential:
    • While magnification also depends on the eyepieces used, the maximum useful magnification of a telescope is typically limited by its aperture. The rule of thumb is that a telescope can provide useful magnification of about 50 times per inch of aperture (or about 2 times per millimeter). Beyond this limit, images tend to be dim and lack detail.
  4. Limiting Magnitude:
    • This refers to the faintest star that can be observed with the telescope. A larger aperture can detect fainter stars and more distant galaxies, revealing more of the universe.
  5. Contrast:
    • Aperture size also affects contrast, which is the ability to see an object against the background sky. A larger aperture can provide better contrast, particularly for observing planets and the Moon. Also Read: The Curious Case of Planets That Spin the Wrong Way
  6. Types of Observations:
    • Large apertures are especially beneficial for deep-sky observations (like nebulae, galaxies, and star clusters) since these objects are often faint.
    • For planetary and lunar observations, where the objects are bright but small and require high resolution to see details, aperture size is also important.
  7. Portability and Convenience:
    • Larger apertures generally mean larger, heavier, and less portable telescopes. It’s a trade-off between optical performance and convenience. For many amateur astronomers, finding a balance between the two is key.
  8. Atmospheric Conditions:
    • Larger apertures are more affected by atmospheric conditions (seeing). If the atmospheric seeing is poor, a smaller telescope may actually provide a better image than a larger one.
Exploring Nebulas and Galaxies
Exploring Nebulas and Galaxies


Magnification is less important than aperture. It’s determined by the telescope’s optics and the eyepiece. High magnification doesn’t always mean better viewing – clarity and brightness are more important.

A common beginner’s misconception is that higher magnification means better viewing. In reality, stability, atmospheric conditions, and light gathering power (aperture) play more significant roles.

Magnification is a fundamental concept in telescopic observations, and understanding it is crucial for anyone interested in using a telescope. Here’s an overview of what magnification is and how it works in the context of telescopes:

  1. Definition of Magnification:
    • Magnification is the process of enlarging the appearance of an object. In telescopes, it’s about making celestial objects appear larger and more detailed than they are to the naked eye.
  2. How Magnification is Determined:
    • The magnification of a telescope is determined by the focal length of the telescope and the focal length of the eyepiece being used.
    • The formula is: Magnification = Focal Length of Telescope / Focal Length of Eyepiece.
    • For example, if a telescope has a focal length of 1200mm and is used with a 25mm eyepiece, the magnification is 1200mm / 25mm = 48x.
  3. Changing Magnification:
    • You can change the magnification by using eyepieces with different focal lengths. A lower focal length eyepiece gives higher magnification.
  4. Limits of Magnification:
    • While it might seem desirable to achieve very high magnification, there are practical limits. High magnifications can lead to dimmer and blurrier images due to atmospheric conditions and the telescope’s aperture.
    • A general rule of thumb for the maximum useful magnification is 50 times the telescope’s aperture in inches or about twice the aperture in millimeters.
  5. Consideration of Aperture:
    • The aperture of a telescope is key to determining how much magnification can be effectively used. A larger aperture gathers more light and can, therefore, support higher magnifications while still providing clear, bright images.
  6. Resolution Limit:
    • Magnification cannot increase the resolving power of a telescope. Even at high magnifications, the telescope cannot resolve details finer than its optical resolution limit, which is determined by its aperture.
  7. The Role of Eyepieces:
    • Eyepieces are essential for determining magnification. A collection of eyepieces with different focal lengths can be more versatile and useful than a single eyepiece with very high magnification.
  8. Practical Viewing:
    • Often, moderate magnification provides the best viewing experience. Extremely high magnifications can be less practical due to image shaking, reduced field of view, and sensitivity to atmospheric disturbances.
  9. Barlow Lenses:
    • A Barlow lens can be used to increase the effective focal length of the telescope, effectively doubling or tripling the magnification provided by any eyepiece used with it. Read more here: Barlow Lens

Also Read: Why We Should See Solar Eclipse


A stable and appropriate mount is crucial. There are two main types: Altazimuth (simpler, up-down and left-right movement) and Equatorial (more complex, aligned with Earth’s axis, better for tracking celestial objects).

Computerized mounts (GoTo mounts) can automatically point the telescope to various celestial objects, which is helpful for beginners.

The mount is a critical component of a telescope system, providing stability and control for astronomical viewing. There are several types of mounts, each with its own advantages and disadvantages. Understanding these can help you choose the right mount for your needs:

  1. Altazimuth Mounts:
    • Simplest Design: Moves up/down (altitude) and left/right (azimuth).
    • Pros:
      • Generally lightweight, easy to set up and use.
      • Suitable for terrestrial and basic astronomical viewing.
    • Cons:
      • Not ideal for long-exposure astrophotography.
      • Can be less smooth in tracking celestial objects across the sky.
    • Best For: Beginners, casual observers, and those on a budget.
  2. Equatorial Mounts:
    • Advanced Design: Aligned with Earth’s axis, moving in right ascension and declination.
    • Pros:
      • Allows smooth tracking of celestial objects by compensating for Earth’s rotation.
      • Essential for serious astrophotography and long-term observation.
    • Cons:
      • More complex to set up and align.
      • Generally heavier and more expensive.
    • Best For: Intermediate to advanced astronomers, especially those interested in astrophotography.
  3. Dobsonian Mounts:
    • Specialized Altazimuth: A simple, effective design primarily used with large reflector telescopes.
    • Pros:
      • Very easy to use and set up.
      • Offers stability for large telescopes at a relatively low cost.
    • Cons:
      • Not suitable for astrophotography.
      • Bulkier, less portable.
    • Best For: Beginners to intermediate users who prioritize ease of use and value.
  4. GoTo and Computerized Mounts:
    • Technologically Advanced: Can be either altazimuth or equatorial, equipped with motors and computers.
    • Pros:
      • Can automatically locate and track celestial objects.
      • Ideal for those who want to find objects without much manual searching.
    • Cons:
      • More expensive.
      • Requires power source.
      • Can be more complex to set up initially.
    • Best For: All levels, particularly those interested in convenience and astrophotography.
  5. Tracking and Motor Drives:
    • Add-Ons for Mounts: Motorized drives can be added to many equatorial mounts for automatic tracking.
    • Pros:
      • Allows for long-exposure astrophotography and easier observation.
    • Cons:
      • Additional cost and complexity.
  6. Portability and Stability:
    • The choice of mount also depends on the need for portability and stability. Larger, heavier mounts offer more stability but are less portable.
  7. Compatibility with Telescope:
    • Ensure that the mount is compatible with your telescope in terms of size, weight, and mounting mechanism.
  8. Ease of Use:
    • Consider how easy the mount is to set up and align, especially if you are a beginner or if you plan to set up and take down your telescope frequently. Read more on Wikipedia about Telescope mount.

Portability and Storage

Portability and storage considerations are important factors when choosing a telescope, especially if you plan to take it to different locations or have limited space at home. Here are some tips and considerations related to portability and storage:


  1. Telescope Type:
    • Reflectors and compound telescopes (like Schmidt-Cassegrains) can be more compact than long-tube refractors, making them easier to transport.
    • Consider telescopes with collapsible or retractable designs for increased portability.
  2. Weight:
    • Larger telescopes with bigger apertures tend to be heavier. If you plan to move your telescope frequently, consider a model that balances aperture size with weight and portability.
  3. Dobsonian Telescopes:
    • Dobsonian mounts are known for their simplicity and ease of use, but larger models can be bulky. Smaller Dobsonians are often more portable.
  4. Transportation:
    • Check if the telescope can be easily disassembled or folded for transportation. Some models are designed to fit in a car trunk, while others might require more space.
  5. Backpack-Friendly:
    • Some smaller telescopes are designed to be carried in a backpack, making them suitable for hiking or travel.
  6. Mount Type:
    • Altazimuth mounts are generally simpler and more portable than equatorial mounts. However, equatorial mounts are essential for certain types of astrophotography.
  7. Telescope Accessories:
    • Consider the ease of transporting accessories like eyepieces, finderscopes, and tripods.
  8. Travel Telescopes:
    • Some telescopes are specifically marketed as “travel telescopes” and come with convenient carrying cases. These are often smaller and more portable.


  1. Size and Shape:
    • Consider where you’ll store the telescope when not in use. Telescopes with compact designs or those that can be disassembled easily may be more suitable for limited storage space.
  2. Protective Cases:
    • Some telescopes come with dedicated storage or carrying cases, providing protection and making storage more convenient.
  3. Temperature and Humidity:
    • Store your telescope in a dry and cool place to prevent damage from humidity and temperature fluctuations.
  4. Collapsible Design:
    • Telescopes with collapsible or retractable designs are not only more portable but also easier to store in smaller spaces.
  5. Secure Storage:
    • Ensure that your storage area is secure to protect your telescope from accidental damage or theft.
  6. Accessories Storage:
    • Consider how and where you will store additional accessories like eyepieces, filters, and other attachments.
  7. Maintenance:
    • Regularly check and maintain your telescope, especially if it’s stored in an area prone to dust or other environmental factors.
  8. Consider Your Living Space:
    • If you have limited living space, you may need to prioritize a telescope that can be easily stored when not in use.


When considering a budget for purchasing a telescope, it’s important to factor in not just the cost of the telescope itself, but also any additional accessories or equipment you might need. Here’s a guide to help you plan your budget:

  1. Entry-Level Telescopes:
    • Price Range: $50 – $200.
    • Suitable For: Beginners, children, or anyone just testing their interest in astronomy.
    • Includes: Small refractors and simple reflectors on basic mounts. Limited capabilities but a good starting point.
  2. Intermediate Telescopes:
    • Price Range: $200 – $800.
    • Suitable For: Enthusiasts with some experience or beginners looking for a more capable setup.
    • Includes: Larger reflectors, some Schmidt-Cassegrain telescopes, and better-quality refractors. These often come with more stable mounts and some may include GoTo functionality.
  3. Advanced Telescopes:
    • Price Range: $800 – $3000+.
    • Suitable For: Serious amateur astronomers and astrophotographers.
    • Includes: High-quality Schmidt-Cassegrain, large aperture Dobsonians, and advanced refractors. High-quality mounts, often with GoTo capabilities and tracking for astrophotography.
  4. Professional-Level Telescopes:
    • Price Range: $3000 and up.
    • Suitable For: Advanced users and professionals.
    • Includes: Top-of-the-line models with large apertures, superior optics, and precision mounts.
  5. Additional Accessories:
    • Eyepieces: A single telescope can offer a range of viewing experiences with different eyepieces. Quality eyepieces can range from $30 to over $300 each.
    • Filters: Useful for enhancing the viewing of planets, the Moon, and deep-sky objects. Can range from $20 to $100+.
    • Barlow Lens: Doubles or triples the magnification of your eyepieces. Prices range from $40 to $150+.
    • Mounts: If not included with your telescope, a good mount can cost from $100 to over $1000.
    • Maintenance and Cleaning Tools: Modest cost but essential for upkeep.
  6. Astrophotography Equipment:
    • Cameras: Specialized astrophotography cameras or adapters for DSLRs. Prices can vary widely.
    • Tracking Mounts: Necessary for long-exposure astrophotography. Higher-end models can be a significant investment.
  7. Consider Second-Hand Equipment:
    • Purchasing used telescopes and accessories can save money. However, it’s important to buy from reputable sources and check the condition of the equipment.
  8. Plan for Upgrades:
    • If you develop a deep interest in astronomy, you may want to upgrade components. Consider this when planning your initial budget.
  9. Joining Astronomy Clubs:
    • Membership fees are typically modest and can provide access to high-quality equipment and valuable advice.
  10. Books and Software:
  • Don’t forget educational materials and stargazing software or apps, which can enhance your experience.

In the end, picking the right telescope is all about finding one that fits what you want to do and how much you want to spend. We’ve gone through the important stuff to think about, so now you should have a better idea of what’s best for you. Remember, the coolest telescope isn’t always the biggest or most expensive one; it’s the one that lets you enjoy the stars and planets in your own way. So take a deep breath, choose the telescope that feels right for you, and get ready for some awesome nights looking up at the sky. Here’s to your star-filled adventures!