5-inch Telescopes (127-130mm)

What is a 5-inch telescope?

A 5-inch telescope is a type of telescope with an aperture (the diameter of the objective lens) of 5 inches (127-130 mm). It is considered a medium-sized telescope, ideal for amateur astronomers and kids. A 5-inch telescope is a powerful optical instrument designed for observing celestial objects in the night sky. It boasts a greater light-gathering power compared to the naked eye, making it ideal for viewing faint objects such as stars, planets, galaxies, constellations, and meteors. The telescope’s light-gathering power is approximately 25 times that of the human eye, allowing for enhanced visibility and resolution in observations. One of the key components of a 5-inch telescope is its aperture, which determines the telescope’s light-gathering power and resolution. The telescope’s resolving power enables it to distinguish fine details in celestial objects, providing a rich viewing experience for astronomers and enthusiasts alike. In terms of magnification, a 5-inch telescope typically offers a maximum magnification of around 225-260x, enabling users to zoom in on distant objects with clarity. The telescope’s focal length, which can vary based on the specific lens and camera system used, plays a crucial role in determining its magnification capabilities. When it comes to mounting, a 5-inch telescope is typically paired with an equatorial mount, providing stability and precision for tracking celestial objects. The telescope’s azimuth measurement further aids in determining the horizontal direction of stars and other astronomical objects in the sky. In addition to its technical specifications, a 5-inch telescope is known for its portability, making it a convenient option for stargazing on the go. Its compact design, lightweight construction, and adjustable tripods contribute to its ease of transport and setup. Furthermore, a 5-inch telescope is equipped with eyepieces that allow for varying levels of magnification and field of view, enhancing the observer’s experience. Double stars, which can be observed using a 5-inch telescope, provide valuable insights into stellar systems and properties. Overall, a 5-inch telescope offers a versatile and powerful tool for exploring the wonders of the night sky, making it a popular choice among amateur astronomers and enthusiasts.

What is a 5-inch refractor telescope?

A 5-inch refractor telescope is a versatile optical instrument designed for both terrestrial and celestial viewing. It offers clear and bright images of various celestial objects, thanks to its 5-inch aperture that allows for significant light-gathering capabilities to observe faint objects in the night sky. The telescope’s focal length typically ranges from 1000-1200mm, providing a balance between magnification capabilities and field of view, making it suitable for observing various celestial objects like planets, stars, galaxies, nebulae, and star clusters.

The 5-inch refractor telescope utilizes a refractor design, employing a convex objective lens and a concave eyepiece lens made of quality glass to reduce chromatic aberration and enhance image quality, especially for astrophotography. The specific type of quality glass used in the lenses, such as FPL-53, extra-low dispersion (ED), or apochromatic glass, may vary depending on the manufacturer and model of the telescope.

The telescope is mounted on an equatorial mount for precise tracking and observation of celestial objects. It comes with a star diagonal to redirect the light path by 90 degrees, allowing comfortable viewing at different angles and producing right-side-up images. The 5-inch refractor telescope offers a maximum magnification of approximately 200x, allowing detailed views of celestial objects with clarity and precision.

What is a 5-inch reflector telescope?

A 5-inch reflector telescope is a type of optical instrument that uses a mirror to gather and focus light from celestial objects. The telescope’s aperture, or the diameter of its primary mirror, is 5 inches, which determines its light-gathering ability and resolution. The telescope typically has a focal ratio of f/5, which provides a wide field of view and fast imaging capabilities. The telescope’s mirror is coated with a reflective material, such as aluminum, to enhance its reflectivity and image quality. The telescope’s mount, such as a Dobsonian or equatorial mount, provides stability and allows for precise tracking of celestial objects. The telescope may come with additional accessories, such as eyepieces, filters, and finder scopes, to enhance the user’s viewing experience.

What space objects can you see with a 5-inch telescope?

A 5-inch telescope is capable of observing a variety of space objects, including planets, double stars, nebulae, and galaxies. The visibility of these objects is influenced by factors such as surface brightness, angular size, and apparent magnitude.

Types and Technical Specifications of 5-inch telescope

Types (Optical Design)

Triplet Refractor: Example: Lunt Solar 130mm Universal Telescope w/ Rack & Pinion Focuser, Lunt Solar 130mm Universal Telescope w/ Lunt Crayford Focuser, Lunt Solar 130mm H-alpha Universal Telescope w/B1200 & Feather Touch Focuser, Lunt Solar 130mm H-alpha Universal Telescope w/B1800 & Feather Touch Focuser, Orion EON 130mm ED Triplet Apochromatic Refractor Telescope, William Optics FLT 132 Triplet Refractor Telescope with Rack and Pinion Focuser – Red & Gold, Lunt Solar 130mm Universal Telescope, Lunt Solar 130mm H-alpha Universal Telescope w/B3400 & Feather Touch Focuser, Explore Scientific 127mm f/7.5 CF FCD100 Triplet Refractor Telescope, Explore Scientific 127mm FCD100 f/7.5 ED APO Triplet Refractor, Meade Polaris 127mm (5 Inch) German Equatorial Reflector Telescope, Explore Scientific 127mm Air-Spaced ED APO f/7.5 Triplet Refracting OTA Telescope, Takahashi TOA-130NS Triplet APO Double ED Refractor – 2.7″ Focuser, Takahashi TOA 130NFB Double ED Triplet Refractor Telescope.

Newtonian: Example: Sky-Watcher Virtuoso GTi 130 Tabletop GoTo Dobsonian, Orion SpaceProbe 130ST Equatorial f/5 Newtonian Reflecting Telescope Kit, Explore Scientific Firstlight N130mm White Tube Newtonian with EXOS Nano EQ3, Celestron Astro Fi 130 mm Newtonian WiFi, Celestron SkyProdigy 130 Computerized Telescope, Celestron AstroMaster 130EQ-MD Telescope with Motor Drive, Celestron NexStar 130SLT Computerized Telescope, Celestron AstroMaster 130EQ Telescope, Celestron PowerSeeker 127 EQ Telescope, Celestron StarSense Explorer DX 130AZ Smartphone Telescope.

Maksutov Cassegrain: Example: Sky-Watcher Skymax 127 AZ-GTi f/12.1 Maksutov Cassegrain Catadioptric Telescope, Explore Scientific FirstLight 127mm Mak-Cassegrain with EXOS Nano EQ3 Mount, Sky-Watcher 127mm Maksutov Cassegrain Telescope OTA.

Petzval: Example: Tele Vue NP 127 FLI f/5.4 Petzval Refracting Telescope, Tele Vue NP127is f/5.2 Petzval Refracting Telescope.

Doublet Refractor: Example: Explore Scientific 127mm f/6.5 Achromatic Refractor with Accessories.

SCT: Example: Celestron NexStar 5SE Computerized Telescope, Celestron C· 5 Schmidt-Cassegrain Spotting Scope.

Quadruplet: Example: Askar 130PHQ APO Quadruplet Astrograph.

Technical Specifications

Aperture: 5-inch (127-130 mm)

Focal Length: 650-1900 mm 

Focal ratio: f/5-f/15

Highest Magnification: 225-260x

Light Gathering Power: 319-356x

Price: 279-8,400$

Images taken with 5-inch telescopes

Examples of 5-inch telescopes

• Lunt Solar 130mm Universal Telescope w/ Rack & Pinion Focuser
• Lunt Solar 130mm Universal Telescope w/ Lunt Crayford Focuser
• Lunt Solar 130mm Universal Telescope w/ Feather Touch Focuser
• Sky-Watcher Virtuoso GTi 130 Tabletop GoTo Dobsonian
• Lunt Solar 130mm H-alpha Universal Telescope w/B1200 & Feather Touch Focuser
• Lunt Solar 130mm H-alpha Universal Telescope w/B1800 & Feather Touch Focuser
• Orion EON 130mm ED Triplet Apochromatic Refractor Telescope
• William Optics FLT 132 Triplet Refractor Telescope with Rack and Pinion Focuser – Red & Gold (5.25’’)
• William Optics FLT 132 Triplet Refractor Telescope with 3.5″ Feather Touch Focuser- Red & Gold (5.25’’)
• Lunt Solar 130mm Universal Telescope
• Lunt Solar 130mm H-alpha Universal Telescope w/B3400 & Feather Touch Focuser
• Sky-Watcher Skymax 127 AZ-GTi f/12.1 Maksutov Cassegrain Catadioptric Telescope
• Orion SpaceProbe 130ST Equatorial f/5 Newtonian Reflecting Telescope Kit
• Explore Scientific 127mm f/7.5 CF FCD100 Triplet Refractor Telescope
• Explore Scientific FirstLight 127mm Mak-Cassegrain with EXOS Nano EQ3 Mount
• Explore Scientific Firstlight N130mm White Tube Newtonian with EXOS Nano EQ3
• Celestron Astro Fi 130 mm Newtonian WiFi
• Explore Scientific 127mm FCD100 f/7.5 ED APO Triplet Refractor
• Meade Polaris 127mm (5 Inch) German Equatorial Reflector Telescope
• Tele Vue NP 127 FLI f/5.4 Petzval Refracting Telescope
• Celestron SkyProdigy 130 Computerized Telescope
• Tele Vue NP127is f/5.2 Petzval Refracting Telescope
• Explore Scientific 127mm f/6.5 Achromatic Refractor with Accessories
• Explore Scientific 127mm Air-Spaced ED APO f/7.5 Triplet Refracting OTA Telescope
• Celestron AstroMaster 130EQ-MD Telescope with Motor Drive
• Celestron NexStar 5SE Computerized Telescope
• Celestron NexStar 130SLT Computerized Telescope
• Takahashi TOA-130NS Triplet APO Double ED Refractor – 2.7″ Focuser
• Celestron C· 5 Schmidt-Cassegrain Spotting Scope
• Takahashi TOA 130NFB Double ED Triplet Refractor Telescope
• Sky-Watcher 127mm Maksutov Cassegrain Telescope OTA
• Celestron AstroMaster 130EQ Telescope
• Celestron PowerSeeker 127 EQ Telescope
• Askar FMA135 Triplet APO Telescope

How do 5-inch telescopes compare to other size-telescopes

5-inch vs 6-inch telescope

5-inch telescopes have less aperture than the 6-inch telescopes. They offer a focal ratio of f/3.9-f/10 whereas the 5-inch telescopes vary from f/5-f/15. However, 6-inch telescopes offer a focal length of 162-1800 mm whereas the 5-inch telescopes vary from 650-1900 mm in focal lengths. 6-inch telescopes provide the highest magnification of 295-320x, whereas 5-inch telescopes can magnify 225-260x. 

5-inch vs 7-inch telescopes

5-inch telescope has less aperture than the 7-inch telescopes. They offer a focal ratio of f/2.8-f/15 whereas the 5-inch telescopes vary from f/5-f/15. Besides, 5-inch telescopes offer a focal length of 650-1900 mm whereas the 7-inch telescopes start from 500 mm to 2700 mm mm in focal lengths. Moreover, 7-inch telescopes provide 360x the highest magnification, whereas 5-inch telescopes can magnify up to 225-260x.

5-inch vs 8-inch telescope

8-inch telescopes provide focal lengths of 800-2415 mm (f/4-f/11.5), while 5-inch vary in focal lengths from 650-1900 mm (f/5-f/15). On average 8-inch telescopes provide the highest magnification of 300-480x, whereas 5-inch telescopes can magnify 225-260x. 

5-inch vs 9.25-inch telescope

5-inch telescopes provide a focal length of 650-1900 mm with a focal ratio of f/5-f/15. In contrast, 9.25-inch telescopes vary from 2350-2500 mm in focal length with a focal ratio of f/10. Moreover, 9.25-inch telescopes provide 406-555x the highest magnification, which is 225-260x in the case of 5-inch telescopes.