Askar 71F Flat-Field Telescope 71mm Aperture F6.9 ED Glass Refractor OTA
4.9Editor score
Quadruplet air-spaced APO design
Lightweight 2.5kg OTA construction
Fully self-flattened field optical
In this guide
Apochromatic refractors represent the pinnacle of optical engineering for serious astronomers and astrophotographers. These telescopes use special low-dispersion glass to eliminate color fringing, delivering crisp, high-contrast images of celestial objects that other designs simply cannot match.
Our team analyzed ten leading models from reputable brands like SVBONY, Explore Scientific, and Askar. We evaluated optical construction, portability, accessory compatibility, and user feedback to determine which scopes offer the best value and performance for different budgets and needs.
Each pick in this list highlights specific strengths whether for visual observing or imaging. Note that pricing and availability fluctuate frequently so always check current listings before purchasing. Use our detailed comparisons to guide your investment in quality astronomical equipment.
Top 3 Picks for Best Apochromatic Refractors
SVBONY SV550 AP0 Telescope 80mm ED F6 Triplet Apochromatic Refractor OTA
4.5Editor score
Triplet APO optics reduce chromatic aberration
Air-spaced triple optical design
Magnesium alloy dual-speed focus mount
SVBONY SV550 APO Telescope Bundle with SV209 Field Flattener 122mm F7 Triplet Apochromatic Refractor
5.0Editor score
122mm aperture gathers more light
FPL-51 triplet apochromatic lens
Includes 0.8X focal reducer flattener
Top 10 Best Apochromatic Refractors in 2026 Compared
The following table compares key specifications across all ten models reviewed in this guide. Focus on aperture size optical design type, and included accessories to find the scope that aligns with your imaging or visual observing goals.
ProductsSpecificationsEditor scorePrice
Editor's Choice
SVBONY SV550 AP0 Telescope 80mm
80mm Aperture F6 Focal Ratio
Triplet Air-Spaced Apochromatic
Magnesium Alloy Focus Mount
Multiple Internal Light Barriers
4.5Editor score
Editor's Choice
Explore Scientific ED80 Essential Series
80mm Aperture F6 Focal Ratio
FCD1 HOYA ED Glass
Air-Spaced Triplet Design
Front Cell Collimation System
4.2Editor score
Best Premium
SVBONY SV550 Telescope 80mm Bundle
80mm Aperture F6 Focal Ratio
Includes SV209 Field Flattener
180mm Hollow Dovetail Plate
Full-Frame Camera Compatible
5.0Editor score
SVBONY SV550 APO Telescope Bundle
122mm Aperture F7 Focal Ratio
FPL-51 Triplet Apochromatic
Portable Handle and Base
Guide Scope Mount Included
4.0Editor score
Askar 71F Flat-Field Telescope
71mm Aperture F6.9 Focal Ratio
Quadruplet Air-Spaced APO
Fully Self-Flattened Field
360 Degree Field Rotator
4.9Editor score
SVBONY SV503 Telescope 102mm
102mm Aperture F7 Focal Ratio
S-FPL51 ED Glass
Dual-Speed Focuser Rotator
90mm Focus Travel Range
4.8Editor score
SVBONY SV550 APO Telescope Bundle 122mm
122mm Aperture F7 Focal Ratio
FPL-51 Triplet Apochromatic
Includes 0.8X Focal Reducer
Field Curvature Correction
5.0Editor score
SVBONY SV550 122mm Triplet APO Kit
122mm Aperture F7 Focal Ratio
FPL-51 Triplet Apochromatic
Includes 0.8X Focal Reducer
Portable Handle and Base
4.0Editor score
SVBONY SV550 80 Triplet APO Kit
80mm Aperture F6 Focal Ratio
FPL-51 Triplet Apochromatic
Includes SV209 Flattener
Comfortable Carrying Handle
4.0Editor score
SVBONY SV550 APO 122mm Bundle
122mm Aperture F7 Focal Ratio
FPL-51 Triplet Apochromatic
Includes Guide Scope and Camera
High Sensitivity 1.23 Megapixel
4.0Editor score
1. SVBONY SV550 AP0 Telescope 80mm – Best Overall Apochromatic Refractor
SVBONY SV550 AP0 Telescope 80mm
80mm Aperture F6 Focal Ratio
Triplet Air-Spaced Apochromatic
Magnesium Alloy Focus Mount
Multiple Internal Light Barriers
The SVBONY SV550 AP0 stands out as our top choice for its balanced performance and value. Rated highly by users, it delivers crisp views thanks to its triplet apochromatic optics. This scope is ideal for both visual observers and beginners in astrophotography seeking reliable color correction.
Pros
- Excellent color correction with triplet design
- Lightweight magnesium alloy focuser
- Strong extinction measures for contrast
- Suitable for full-frame cameras
- Competitive pricing for APO quality
Cons
- OTA only without mounting hardware
- Dew shield not included
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Its triplet structure uses S-FPL51 ED glass paired with correction glass to virtually eliminate chromatic aberration. The air-spaced design prevents internal reflections while the dual-speed toothed focus mount offers precise adjustments. Multiple internal light barriers ensure high contrast even under light-polluted skies.
While the scope performs admirably, it lacks included accessories like a mount or case. Users must budget separately for these items which adds to the total cost. However, the magnesium alloy construction reduces weight significantly making transport easier for portable sessions.
We recommend this telescope for observers who prioritize optical quality and portability. Whether targeting Messier objects or deep-sky imaging, it provides a robust platform. The attention to detail in extinction and focus control makes it a standout in its class.
Superior Color Correction
The triplet air-spaced design effectively eliminates blue-edge chromatic aberration ensuring sharp star points across the field of view.
Portability and Weight
Magnesium alloy materials reduce the weight by over twenty percent compared to aluminum enhancing ease of transport for field sessions.
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2. Explore Scientific ED80 Essential Series – Best for USA Support
Explore Scientific ED80 Essential Series
80mm Aperture F6 Focal Ratio
FCD1 HOYA ED Glass
Air-Spaced Triplet Design
Front Cell Collimation System
The Explore Scientific ED80 offers reliable performance with genuine FCD1 HOYA ED glass. Its proprietary coatings enhance contrast and detail making it suitable for planetary and deep-sky work. The collimation system ensures tight stars critical for astrophotography success.
Pros
- Genuine FCD1 HOYA ED glass
- Enhanced multi-layer coatings
- Collimation system for precision
- Compact retractable dew shield
- USA-based customer support
Cons
- Lower rating than competitors
- Standard weight for 80mm
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Designed with portability in mind, this model features a retractable dew shield and compact focal length. Users appreciate the ease of use for spontaneous stargazing or guiding setups. The USA support base provides peace of mind for warranty or technical issues.
Some users report the collimation adjustment can be tricky initially. However, once set it maintains alignment well. The trade-off is a slightly heavier design compared to magnesium options which may impact travel setups.
Ideal for astronomers in the US seeking trusted support and quality glass. It balances performance with accessibility making it a solid mid-tier choice for both imaging and visual use without extreme budget constraints.
Optical Glass Quality
FCD1 HOYA ED glass combined with proprietary coatings produces high-contrast views filled with stunning detail on celestial targets.
Precision Collimation
Front cell push-pull adjustments allow for optimal collimation ensuring the tightest stars for critical imaging sessions.
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3. SVBONY SV550 Telescope 80mm Bundle – Best Bundle for Imaging
SVBONY SV550 Telescope 80mm Bundle
80mm Aperture F6 Focal Ratio
Includes SV209 Field Flattener
180mm Hollow Dovetail Plate
Full-Frame Camera Compatible
This bundle offers the SV550 OTA paired with the SV209 field flattener. It holds a perfect rating reflecting strong user satisfaction. The flattener corrects field curvature ensuring sharp stars across the entire frame which is vital for deep-sky imaging.
Pros
- Includes essential field flattener
- Corrects field curvature effectively
- Supports full-frame cameras
- Magnesium alloy focus seat
- Excellent customer ratings
Cons
- Higher price than OTA only
- Flattener requires careful setup
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The magnesium alloy focus seat reduces weight significantly. An 180mm hollow dovetail plate provides stability and compatibility with various accessories. Back focal length adapters ensure correct spacing for standard sensors.
Users must account for the additional weight of accessories during transport. While the flattener is crucial for images it requires precise spacing. This adds complexity for beginners compared to visual-only setups.
Best for astrophotographers ready to capture high-quality images immediately. The inclusion of optical correction saves money and time hunting for compatible components. It remains a top choice for those prioritizing imaging performance.
Complete Imaging Solution
The included SV209 flattener corrects field curvature allowing for sharp stars across the entire sensor including full-frame cameras.
Stable Mounting
An 180mm hollow dovetail plate provides a stable base with diverse accessory options for secure imaging setups.
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4. SVBONY SV550 APO Telescope Bundle – Best Portability Kit
SVBONY SV550 APO Telescope Bundle
122mm Aperture F7 Focal Ratio
FPL-51 Triplet Apochromatic
Portable Handle and Base
Guide Scope Mount Included
This kit features a 122mm aperture SV550 refractor which gathers significantly more light than smaller scopes. It is bundled with a dovetail base and handle making it easier to carry. The guide scope bracket allows for precise tracking setup.
Pros
- Large 122mm aperture
- Portable handle and dovetail base
- Guide scope bracket included
- Tripet APO optics
- Easy installation
Cons
- OTA weight at 6.44kg
- High price point
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The FPL-51 triplet design provides excellent correction of aberrations enhancing clarity and sharpness. Users note its suitability for faint deep-sky objects due to higher limiting magnitude. The assembly is straightforward reducing setup time.
While the optics are strong the overall weight is substantial. This may limit portability for hikers or those seeking ultra-light setups. Additionally the price point places it above entry-level options.
Best for those needing larger aperture and a ready-to-use kit. The guide scope bracket simplifies autoguiding which is essential for long exposures. It is a robust tool for serious observers ready to invest.
Large Aperture Light Gathering
The 122mm aperture gathers more light revealing fainter deep-sky objects and providing clear detailed images for observation.
Ready-to-Use Kit
Includes a dovetail base and guide scope bracket enabling quick installation and diverse accessory options for travel.
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5. Askar 71F Flat-Field Telescope – Best Budget Apochromatic Refractor
Askar 71F Flat-Field Telescope
71mm Aperture F6.9 Focal Ratio
Quadruplet Air-Spaced APO
Fully Self-Flattened Field
360 Degree Field Rotator
The Askar 71F is a compact lightweight option perfect for travel. Rated 4.9 it offers a quadruplet air-spaced APO design. The fully self-flattened field removes the need for external flatteners simplifying your imaging train.
Pros
- Extremely lightweight 2.5kg
- Self-flattened field
- Quadruplet APO design
- 360 degree rotation capability
- Affordable pricing
Cons
- Small 71mm aperture
- Limited to smaller sensors
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Weighing only 2.5kg it is easy to carry and mount. The 360-degree rotation allows perfect camera alignment without tube rotation. The matte paint finish reduces stray light reflection improving image contrast significantly.
Its smaller aperture limits light-gathering power compared to larger scopes. It may struggle with very faint deep-sky targets but excels on brighter objects. Budget-conscious buyers will appreciate the cost savings.
Ideal for beginners or those prioritizing portability. It offers professional features in a small package. Use this for quick astrophotography sessions or visual observing where weight is a major concern.
Ultra-Lightweight Design
With an overall weight of 3kg this scope is easy to carry and use for travel sessions and spontaneous stargazing.
Self-Flattened Field
The fully self-flattened optical design allows use for visual or photographic composition without extra optical accessories.
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6. SVBONY SV503 Telescope 102mm – Best for Visual Detail
SVBONY SV503 Telescope 102mm
102mm Aperture F7 Focal Ratio
S-FPL51 ED Glass
Dual-Speed Focuser Rotator
90mm Focus Travel Range
This model features a 102mm aperture with FMC coatings to maximize light transmission. The S-FPL51 ED glass minimizes color fringing ensuring true-to-life colors. It is well-suited for planetary observation and deep-sky photography.
Pros
- 102mm large diameter
- FMC coatings reduce reflections
- 90mm focus travel
- Dual-speed focuser
- 360 degree field rotator
Cons
- No external dew shield mentioned
- Standard 700mm focal length
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The dual-speed focuser offers precision adjustments. Coupled with a 360-degree field rotator alignment is seamless. With 90mm of focus travel you can accommodate various accessories like filter wheels without issue.
The retractable hood helps prevent dew and stray light. However it may not be as robust as hard shells. Overall the build quality is solid for the price range.
Recommended for astronomers seeking a larger aperture for visual detail. It balances performance and versatility making it a great all-rounder. Whether observing planets or imaging galaxies it delivers bright high-contrast images.
Reduced Chromatic Aberration
S-FPL51 ED glass significantly minimizes color fringing allowing for sharp detail on planetary and deep-sky targets.
Precision Focus Control
A smooth dual-speed focuser and 90mm travel enable critical focus even with heavy astrophotography accessories attached.
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7. SVBONY SV550 APO Telescope Bundle 122mm – Best Premium Apochromatic Refractor
SVBONY SV550 APO Telescope Bundle 122mm
122mm Aperture F7 Focal Ratio
FPL-51 Triplet Apochromatic
Includes 0.8X Focal Reducer
Field Curvature Correction
This bundle pairs a 122mm aperture refractor with a SV209 field flattener and 0.8X focal reducer. Rated 5.0 it is a complete solution for astrophotography. The optics correct field curvature and widen the field for impressive wide-field shots.
Pros
- 122mm large aperture
- Complete imaging bundle included
- 0.8X focal reducer
- Superior field correction
- Perfect user ratings
Cons
- Highest price in selection
- Heavy for travel
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The FPL-51 triplet lens provides excellent correction of aberrations. With a focal reducer it speeds up exposures for better imaging efficiency. The larger aperture captures fainter targets effectively.
This is a premium option requiring significant investment. The combined weight of scope and accessories can be cumbersome for transport. However the optical quality justifies the cost for serious imaging.
We recommend this for those ready to commit to astrophotography. It offers top-tier optics and all necessary accessories. The inclusion of a focal reducer adds versatility for both wide-field and detailed imaging.
Wide Field Capability
The SV209 0.8X focal reducer corrects field curvature and widens the field for stunning wide-field astrophotography.
Superior Optics
A 122mm aperture gathers more light revealing fainter deep-sky objects with enhanced clarity and sharpness.
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8. SVBONY SV550 122mm Triplet APO Kit – Best Complete Kit
SVBONY SV550 122mm Triplet APO Kit
122mm Aperture F7 Focal Ratio
FPL-51 Triplet Apochromatic
Includes 0.8X Focal Reducer
Portable Handle and Base
This kit offers a 122mm aperture refractor designed for deep-sky work. It comes with a portable handle and base base carrying ease. A 0.8X focal reducer is included to improve imaging efficiency.
Pros
- Large 122mm aperture
- Portable handle and base
- Includes focal reducer
- High optical quality
- Deep-sky photography ready
Cons
- Heavy for backpacking
- Requires separate mount
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The FPL-51 triplet lens ensures high quality color correction. Users appreciate the clarity and sharpness of images. It is suitable for fainter objects due to the high limiting magnitude.
The combined weight requires careful transport planning. While manageable with a case it is not ideal for backpacking. Additionally a separate mount is needed for operation which adds to total setup cost.
Best for those needing a large aperture kit for imaging. It simplifies the setup with essential components included. The optical performance remains top-tier for serious observers and photographers.
Travel Ready Design
A portable handle and dovetail base make the large-aperture telescope easy to carry and move to dark sites.
Imaging Efficiency
The included 0.8X focal reducer improves imaging quality and efficiency across the field of view.
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9. SVBONY SV550 80 Triplet APO Kit – Best Value Kit
SVBONY SV550 80 Triplet APO Kit
80mm Aperture F6 Focal Ratio
FPL-51 Triplet Apochromatic
Includes SV209 Flattener
Comfortable Carrying Handle
This kit combines the SV550 80mm OTA with a field flattener. It provides a complete package for imaging at a reasonable price. The triplet optics ensure sharp views without excessive chromatic aberration.
Pros
- Affordable 80mm package
- Includes field flattener
- Triplet optics
- Carrying handle included
- Full multilayer coatings
Cons
- Heavier than 71mm model
- Standard 80mm aperture
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Coated lens elements deliver bright and clear images. The included carrying handle improves transport safety. Observers can target Messier catalog items with relative ease.
While heavier than the smaller Askar it offers more light gathering. The price is higher than the OTA only version but includes necessary accessories. It remains a solid option for budget-conscious buyers.
Ideal for those seeking a ready-to-image setup without breaking the bank. The included flattener corrects edge issues making it a practical choice. It is a strong contender for beginners upgrading to APO.
Sharp Imaging
Ultra-wide band multilayer coated lenses prevent reflections ensuring bright and clear images for photography.
Ease of Transport
A comfortable carrying handle and safety adjustments make installation and transport convenient for users.
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10. SVBONY SV550 APO 122mm Bundle – Best Complete Astrophotography Kit
SVBONY SV550 APO 122mm Bundle
122mm Aperture F7 Focal Ratio
FPL-51 Triplet Apochromatic
Includes Guide Scope and Camera
High Sensitivity 1.23 Megapixel
This comprehensive bundle includes a 122mm refractor with guide scope and camera. It is a complete kit for astrophotography. The camera features a 1.23-megapixel sensor suitable for autoguiding or planetary imaging.
Pros
- Includes guide scope and camera
- High-sensitivity guide camera
- Large 122mm aperture
- Apochromatic lens structure
- Compatible guiding interface
Cons
- Camera is 1.23 megapixel
- Bundle price is high
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The high-sensitivity guide camera ensures tight tracking of faint guide stars. With a 1.25in and M42 mount it is compatible with mainstream cameras. The triplet lens provides excellent clarity for deep-sky targets.
While the camera is compact it may not satisfy advanced planetary needs. Users needing higher resolution may upgrade later. The guide scope setup is robust for tracking long exposures effectively.
Best for those needing an all-in-one imaging solution. It simplifies setup by providing essential guiding components. Ideal for serious observers ready to capture detailed deep-sky images without searching for parts.
Autoguiding Ready
The included guide camera allows tight tracking of faint stars perfect for long exposure deep-sky astrophotography.
Broad Compatibility
Standard 1.25in and M42 interfaces ensure compatibility with various guiding cameras and accessories.
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Buying Guide – How to Choose the Best Apochromatic Refractors
Choosing the right apochromatic refractor involves evaluating optical quality portability and accessory compatibility. Use this guide to navigate key factors that impact your observing or imaging success.
Aperture Size
Aperture determines how much light a telescope gathers. Larger apertures like 122mm reveal fainter objects but add weight. Smaller 80mm models balance portability with light-gathering ability.
Select an aperture based on your transport needs and target list.
Optical Design
APO refractors use triplet or quadruplet designs to eliminate chromatic aberration. Air-spaced glass prevents internal reflections. FPL-51 or ED glass ensures color correction.
Look for triplet or quadruplet air-spaced optics for the best color performance.
Focal Ratio
Focal ratio affects imaging speed and field of view. F/6 to F/7 is ideal for deep-sky. Faster scopes allow shorter exposures but may need more correction.
Prioritize F/6 to F/7 for general astrophotography and visual use.
Portability
Weight impacts how easily you can transport your scope. Magnesium alloy mounts reduce weight. Compact tubes allow easier packing in vehicles.
Choose lightweight materials and manageable tube length for travel.
Accessory Compatibility
Check if a flattener is included or needed. Field flatteners correct curvature for flat sensors. Ensure the back focus distance matches your camera.
Ensure your setup includes a field flattener for flat images.
Mounting Requirements
Most OTAs do not include mounts. You will need a sturdy equatorial mount capable of handling the payload. Consider dovetail plates for stability.
Budget for a compatible mount capable of supporting the OTA weight.
Focuser Type
Dual-speed focusers allow precise adjustments. 360-degree rotation simplifies camera alignment. Metal construction ensures durability.
Prioritize dual-speed focusers for accurate imaging focus.
Budget Considerations
APO scopes range from affordable kits to premium bundles. Consider total cost including accessories like mounts and flatteners. Balance performance with your total budget.
Set a realistic total budget including essential accessories.
How to Use and Care for Your Apochromatic Refractors
Set up your telescope on a stable mount in a dark area. Align the mount to ensure accurate tracking of celestial objects. Use the focuser to achieve a sharp image on stars.
If imaging, attach a field flattener and ensure correct back focus distance. Allow the scope to cool to ambient temperature to reduce thermal currents. Use dew shields or heaters to prevent condensation on lenses.
Clean optics only when necessary using a soft brush or air blower. Store the scope in a dry case to prevent moisture damage. Regularly check collimation to maintain optical alignment and performance.
Frequently Asked Questions
What is an apochromatic refractor?
An apochromatic refractor uses specialized glass like ED or FPL-51 to eliminate color fringing. It delivers sharp high-contrast images without the purple halos seen in standard achromats.
Are apochromatic refractors good for astrophotography?
Yes they are excellent for imaging due to their color correction and flat fields. Ensure you use a field flattener to correct field curvature for flat sensors.
Do I need a mount with these scopes?
Most OTAs are sold without mounts. You will need a sturdy equatorial mount capable of supporting the scope's weight for successful imaging or stable viewing.
Which aperture is best for beginners?
An 80mm aperture offers a balance of light gathering and portability. It is manageable for transport and capable of resolving deep-sky and planetary targets.
Do triplet designs correct color better?
Triplet designs use three elements to better correct chromatic aberration than doublets. This results in cleaner images across the entire field of view.
How do I prevent dew on lenses?
Use a retractable dew shield or heating strip to keep the front lens above dew point. Allow the scope to acclimate to outdoor temperatures before use.
Final Thoughts on Choosing the Best Apochromatic Refractors
We recommend the SVBONY SV550 AP0 for overall performance or the Askar 71F for portability. Both offer strong optical quality suitable for serious observers.
Prioritize optical design and accessory compatibility based on your imaging or visual needs. A field flattener and proper mount are essential for best results.
Always check current prices and availability before purchasing. Conditions and product details may change over time.