Radian Raptor 61 review [12 aspects]

Dive into the celestial wonders with our in-depth review of the first telescope offering from Radian Telescopes, a triplet apochromatic refractor telescope meticulously designed for wide-field, deep-sky astrophotographers.

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Summary table of features

Image circle44mm
Optical designApochromatic Triplet optical design
Focus knobs10:1 Dual Speed with locking focus knobs
Optional electronic focuser designNon-Helical Rack & Pinion optional electronic focuser
Filter attachment2″ / M48 Filter Vault filter attachment
Case styleRadian Padded Insert Backpack
Focal length275mm
Focal ratiof/4.5
Optical designPetzval Refractor
Integrated correctorIntegrated corrector with three-element design
Dew shieldDew shield included
Dust covers: are front dust covers included?Front covers included
Dust covers: are rear covers included?Rear covers included
Rear camera connectionM48x0.75 rear camera connection (wide T-Ring compatible)
Rotator360 degrees with locking knob
OTA length (dew shield retracted)235mm (dew shield retracted)
OTA outer diameter w/o Hex RingsOTA outer diameter w/o Modular Rings – 80mm
OTA outer diameter OTA outer diameter – 90mm with dew shield retracted
Included dovetails6.5″ universal Losmandy D Style and 4″ Vixen V Style
Recommended back focus55mm (can be reached with included adapters)
Tube ringsTube rings: Radian Modular Hex Rings
Weight4 lbs

Main features

From its innovative optical design to crucial features like Radian Modular Hex Rings, filter vault, optional electronic focuser, filter attachment, corrector’s three-element design, and Radian Padded Insert Backpack, we explore the technical aspects that contribute to the capability of the first telescope offering from Radian Telescopes to capture stunning wide-field, deep-sky imagery.

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1. Optical design

This ultimate portable astrophotography telescope stands out with its advanced apochromatic triplet optical design.

radian raptor61 review
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This scope features three lenses to achieve apochromatic correction, ensuring minimal chromatic aberration and delivering high-quality, color-accurate images.

The triplet configuration optical design enhances the telescope’s capability to produce sharp and detailed visuals, making it an ideal choice for astrophotographers seeking precise and vibrant images of celestial objects.

2. Aperture and focal length

The Radian Raptor 61 boasts a well-balanced combination of OTA outer diameter and aperture, and focal length, making it a versatile tool for astrophotography.

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image credit: astrobackyard.com

With a 61mm aperture, this telescope allows for the collection of ample light, enabling clear and detailed observations of celestial objects.

The 275mm focal length enhances the telescope’s ability to capture a wide field of view, making it particularly well-suited for wide-field astrophotography.

The f/4.5 system of the focal ratio further emphasizes its efficiency in gathering light, making it a valuable asset for capturing deep-sky images with shorter exposure times.

3. Compact design

One of the standout features of the Radian Raptor 61 is its thoughtfully engineered compact design, which caters to the needs of astrophotographers on the move.

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The telescope’s tube with front with rear covers included and Radian Padded Insert Backpack weighs in at a mere 4 pounds, enhancing its portability without compromising on performance.

4. Custom features for astrophotography

The telescope aims to set itself apart with a suite of custom features tailored for astrophotography enthusiasts, ensuring a seamless and high-performance imaging experience.

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Premier apochromatic triplet optics

The scope features top-of-the-line apochromatic triplet optics and full-frame sensors, guaranteeing pristine image quality by minimizing chromatic aberration and delivering sharp, true-color images of celestial objects.

Radian Hex Rings with integrated cable management

The inclusion of custom tube rings – Radian Modular Hex Rings – not only adds a touch of elegance but also incorporates integrated cable management channels, providing a tidy and organized setup for astrophotographers.

Huge full-frame image circle with dedicated corrector

The scope features a dedicated corrector, eliminating the need for an additional reducer/flattener.

The three-element corrector is designed to maintain sharp stars across the image, accommodating sensors as large as a full frame. This ensures compatibility with DSLRs, mirrorless cameras, and dedicated astronomy cameras.

Versatile mount compatibility

The telescope arrives with a 4″ V-style dovetail and a Radian 6.5″ universal D-style plate, ensuring out-of-the-box compatibility with a wide range of mounts.

This flexibility simplifies the setup process and enhances the telescope’s adaptability to different astrophotography setups.

Wide T-Ring compatible

The telescope has a rear camera connection and is Wide T-Ring compatible.

It enhances the versatility of the telescope, allowing astronomers to use a variety of camera systems for capturing the night sky.

Filter vault

The filter vault is designed to accommodate 2-inch filters with an M48 thread. This feature allows astronomers and astrophotographers to easily integrate filters into their observation or imaging sessions.

5. Materials used

The Radian Raptor 61 showcases meticulous craftsmanship and a commitment to high-quality materials, ensuring a durable and reliable instrument for astrophotography.

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Apochromatic triplet optical design

At the core of the Radian Raptor 61’s optical system is an apochromatic triplet design, incorporating three premium glass elements.

This advanced optical arrangement effectively addresses chromatic aberration, delivering exceptionally clear and crisp images devoid of unwanted color fringing.

Premium glass with multi-coatings

The telescope uses premium glass elements that are complemented by advanced multi-coatings.

These coatings serve a dual purpose by enhancing light transmission and reducing reflections, resulting in images that are not only sharp but also free from optical artifacts and glare.

Reflection-free image quality

The meticulous choice of materials and coatings in the Raptor 61 significantly minimizes reflections, ensuring an ultra-clean overall image.

Astrophotographers can capture stunning visuals without the interference of distracting artifacts, allowing for an immersive and true-to-life representation of celestial objects.

The use of premium materials, such as the lightweight yet durable aluminum optical tube, contributes to the overall portability of the telescope.

Optics performance

At the heart of any telescope’s prowess is its optics performance, a critical factor that determines the clarity, precision, and color accuracy of the night sky.

6. Magnification

The Radian Raptor 61’s magnification capabilities are determined by its focal length of 275mm and focal ratio of f/4.5.

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With a maximum useful magnification of 122 and a limit value of 12.3 magnitudes, astronomers can achieve detailed observations of celestial objects, including planets, star clusters, and galaxies, providing versatility for a range of astronomical pursuits.

7. Light gathering capacity

The 61mm aperture of the Raptor 61 plays a crucial role in its ability to gather light. With a light-gathering capacity of 80, this telescope allows astronomers to collect a significant amount of light, enhancing visibility and image brightness.

This is particularly advantageous when observing faint deep-sky objects or conducting astrophotography in low-light conditions.

8. Resolving capacity

Resolving capacity refers to the telescope’s ability to distinguish fine details in observed objects. The Raptor 61, with a resolving capacity of 2.26, demonstrates a high level of optical precision.

This characteristic is essential for capturing sharp and clear images of celestial subjects, contributing to the telescope’s effectiveness in both visual observation and astrophotography.

9. Included accessories

The Radian Raptor 61 comes equipped with a suite of accessories designed to enhance the user experience and provide astrophotographers with the tools they need for successful imaging sessions.

Carry case: a dedicated carry case is included, ensuring secure transportation and storage of the telescope. This protective case adds to the overall portability of the Raptor 61, allowing users to easily transport their equipment to prime stargazing locations.

Dew shield: the telescope features an integrated dew shield, protecting against dew formation on the optics during observation sessions. The dew shield ensures optimal viewing conditions, especially in environments with varying temperatures and humidity levels.

Corrector: the Raptor 61 includes an integrated corrector, eliminating the need for additional reducers or flatteners. This three-element corrector is factory-matched to the telescope, contributing to sharp star images across the entire field, making it an “always-on” solution for imaging.

Tube clamps: the telescope comes with integrated tube clamps, ensuring a secure grip on the optical tube assembly. These clamps contribute to the stability of the telescope and provide ease of use during setup and adjustment.

Prism rail: the included Vixen-style prism rail enhances mounting versatility, allowing users to attach various accessories such as finderscopes, guide scopes, or imaging accessories to customize their setup.

Finder scope: the Raptor 61 is equipped with finder scope, aiding users in locating and framing celestial objects before engaging in astrophotography.

Eyepiece adaptor: the telescope provides flexibility with a 1.25″ and 2″ eyepiece adaptor, allowing users to choose from a variety of eyepieces for visual observations.

Thread for camera tripod: the presence of a thread for a camera tripod adds to the convenience of setting up the Raptor 61 for both visual observation and astrophotography.

10. Focuser design

The Radian Raptor 61 is equipped with a precision focuser designed to enhance the user’s control over focus adjustments. The key features of the focuser include a 1:10 gear reduction for fine movement, allowing for precise and minute adjustments during observations.

With an adjustment range of 55mm, users have flexibility in focusing on a wide range of celestial objects.

The focuser’s gear rack build ensures stability and durability, providing a reliable mechanism for achieving and maintaining focus.

The generous free aperture of 44mm allows for a substantial amount of light to reach the imaging or eyepiece equipment, contributing to the overall optical performance of the telescope.

The connecting threaded socket on the camera side is M48, offering compatibility with a variety of accessories and allowing astrophotographers to attach their cameras securely, and you don’t have to purchase a suitable mounting plate.

11. Application

The Radian Raptor 61 is a versatile telescope designed to excel in specific areas of astronomical observation and astrophotography.


The Raptor 61 demonstrates exceptional performance in astrophotography. With its apochromatic triplet optics, wide-field capabilities, and dedicated corrector, this telescope is well-suited for capturing stunning images of celestial objects and clear night sky.

Moon & planets

The telescope is adept at observing the Moon and planets, offering detailed and sharp views of the lunar surface, planetary features, and atmospheric phenomena.

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Astrophotographers and observers alike can appreciate the Raptor 61’s capabilities in capturing the beauty of our celestial neighbors.

Nature observation

While the Radian Raptor 61 excels in astronomical applications, it is not specifically designed for terrestrial or nature observation.

The telescope’s focal length, magnification, and optics are optimized for celestial targets, and its design may not provide the best experience for terrestrial viewing.

Nebulae & galaxies

The telescope’s wide-field capabilities and advanced optics make it particularly effective for observing and imaging nebulae and galaxies.

The Raptor 61’s ability to capture faint details in deep-sky objects ensures that astronomers can explore and document the intricacies of these celestial wonders with clarity and precision.

12. Recommended user groups


Recommendation: no

The Radian Raptor 61, with its advanced features (such as Modular Hex Rings) and specialized design for astrophotography, may present a steeper learning curve for beginners.

While it offers exceptional performance, individuals new to astronomy might benefit from telescopes with simpler setups and user-friendly features.


Recommendation: yes

The Raptor 61 is well-suited for advanced users who have experience in astronomy and astrophotography.

Its premium optics, Hex Rings, wide-field capabilities, and compatibility with advanced imaging equipment make it an ideal choice for those seeking a high-performance telescope to capture detailed and breathtaking images of the cosmos.


Recommendation: no

The suitability of the Radian Raptor 61 for observatories is not explicitly provided. Observatories with specific requirements may find the telescope’s advanced features advantageous.


In conclusion, the first telescope offering from Radian Telescopes stands as a formidable astrophotography instrument with advanced optical design, making it a compelling choice for enthusiasts seeking unparalleled performance in capturing the wonders of the cosmos.


What is the focal length of the Radian 61?

The focal length of the Radian 61 is 275mm, contributing to its versatility in capturing a range of celestial objects with precision.

How much does a Radian 61 triplet Apo weight?

The Radian 61 triplet Apo weighs approximately 4 pounds, ensuring a lightweight and portable solution for astrophotographers on the move.

Who makes Askar telescopes?

Askar telescopes are manufactured by Askar Scientific, a company dedicated to producing high-quality optics for astronomy and imaging applications.

Ida Stewart

I have had the incredible opportunity to work as a tour guide at the planetarium for over 5 years. Ever since I was a child, astronomy has held a special place in my heart, and I have nurtured a deep passion for exploring the wonders of the universe. Among all the celestial bodies, Mars has always fascinated me the most, captivating my imagination with its mysterious allure.

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