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20 Best Focal Length For Astrophotography (2023 Updated)

Focal length is the distance from the lens to the image sensor. The longer the focal length, the higher the magnification. For example, a 100mm lens will have twice the magnification of a 50mm lens.

Focal length is an important consideration for astrophotography because it determines the field of view and the amount of light that is gathered. A longer focal length will result in a narrower field of view, but more light will be gathered.

This is important for faint objects such as galaxies and nebulae. A shorter focal length will result in a wider field of view, but less light will be gathered. This is important for bright objects such as the moon and planets.

20 Best Focal Length For Astrophotography

Product Image Product Name Features Price

Sky-Watcher Evostar 100ED / ProED 100mm Doublet Apo Refractor

  • 100 mm APO Refractor with ED Schott glass, 900 mm focal length f/9, Dual-speed 2 inch Crayford-type focuser with 1.25 inch adaptor.

Orion AstroView 6 Equatorial Reflector Telescope

  • Reflector Telescope.
  • Treat yourself, your friends, and your family to some wondrous evenings under the stars with the Orion AstroView 6 Equatorial Reflector Telescope!

Sky Watcher ProED 80mm Doublet Apo Refractor Telescope

  • 80 mm

Zhumell – 12-Inch Dobsonian Reflector Telescope – Large Aperture for Crisp, Bright Images – Solid Base Construction with Handle for Easy Transport –

  • 12 Inch

Sky-Watcher Evostar 72 Apo Refractor

  • PORTABLE TRAVEL SIZE: Using a compact design, this refractor is easy to transport and lightweight to support, making it the perfect travel companion.

Rokinon 135mm F1.8 AF Full Frame Auto Focus Telephoto Lens for Sony E Mount Cameras

  • Superb resolution and light in weight with the newly designed optical system.
  • Ultra-precision Aspherical lens offering a soft and beautiful bokeh.

Celestron 11" Rowe-Ackermann Schmidt Astrograph V2 Ota

  • ** Due Oct 2022.
  • Fast, wide-field 11” f/2.2 optical design with rare-earth glass for images free of false color, coma, and field curvature.

Sky Watcher 6in. Traditional Dobsonian Telescope

  • 6 in

Sigma 200-500mm f/2.8 Apo EX DG for Sigma

  • ELD and SLD glass
  • HSM (Hyper Sonic Motor)
  • Internal focusing and internal zooming

Celestron SkyProdigy 130mm Reflector Telescope

  • 307×130

Tamron SP AF 17-50mm f/2.8 XR di II LD [IF] Lens for Nikon

  • Optimized for Digital SLR.
  • Enhanced Peripheral Illumination.
  • Internal Surface Coating to Reduce Ghosting and Flare.

Orion 10" f/4 Newtonian Reflector Astrograph

  • quick-collimation cap is included.
  • distance is 92.4mm from the 2″ drawtube collar. Weighs 33 lbs., 12 oz.

Bower 500mm f/8 Manual Focus Telephoto T-Mount Lens

  • High-power 500mm telephoto focal length
  • Includes T-mount adapter for digital and 35mm Canon EOS SLR cameras
  • High index, low-dispersion multi-coated optical glass to reduce flare

Celestron 8 inch EdgeHD Ota Optical Tube

  • 8″ f/10 (2032mm) Edge HD with Starbright XLT coatings
  • 9×50 optical finderscope
  • 40mm Plossl eyepiece

Celestron – Inspire 100AZ Refractor Telescope

  • Inspire 100az Refractor Telescope

Cassini 1000mm x 120mm Reflector Telescope Smartphone Adapter

  • 1000 mm X 120 mm

Celestron CGX 1100 Rowe-Ackermann Schmidt Astrograph Telescope 12060

  • 11 inch

Celestron 36 cm Rasa Rowe-Ackermann Schmidt Astrograph Ota – 91077

  • 14″ / 2.2

Sky Watcher 150mm Esprit Ed Triplet Apo Refractor

  • 150 mm
Sky-Watcher Evostar 100ED / ProED 100mm Doublet Apo Refractor
  • 100 mm APO Refractor with ED Schott glass, 900 mm focal length f/9, Dual-speed 2 inch Crayford-type focuser with 1.25 inch adaptor.
Orion AstroView 6 Equatorial Reflector Telescope
  • Reflector Telescope.
  • Treat yourself, your friends, and your family to some wondrous evenings under the stars with the Orion AstroView 6 Equatorial Reflector Telescope!
Sky Watcher ProED 80mm Doublet Apo Refractor Telescope
  • 80 mm
Zhumell – 12-Inch Dobsonian Reflector Telescope – Large Aperture for Crisp, Bright Images – Solid Base Construction with Handle for Easy Transport –
  • 12 Inch
Sky-Watcher Evostar 72 Apo Refractor
  • PORTABLE TRAVEL SIZE: Using a compact design, this refractor is easy to transport and lightweight to support, making it the perfect travel companion.
Rokinon 135mm F1.8 AF Full Frame Auto Focus Telephoto Lens for Sony E Mount Cameras
  • Superb resolution and light in weight with the newly designed optical system.
  • Ultra-precision Aspherical lens offering a soft and beautiful bokeh.
Celestron 11" Rowe-Ackermann Schmidt Astrograph V2 Ota
  • ** Due Oct 2022.
  • Fast, wide-field 11” f/2.2 optical design with rare-earth glass for images free of false color, coma, and field curvature.
Sky Watcher 6in. Traditional Dobsonian Telescope
  • 6 in
Sigma 200-500mm f/2.8 Apo EX DG for Sigma
  • ELD and SLD glass
  • HSM (Hyper Sonic Motor)
  • Internal focusing and internal zooming
Celestron SkyProdigy 130mm Reflector Telescope
  • 307×130
Tamron SP AF 17-50mm f/2.8 XR di II LD [IF] Lens for Nikon
  • Optimized for Digital SLR.
  • Enhanced Peripheral Illumination.
  • Internal Surface Coating to Reduce Ghosting and Flare.
Orion 10" f/4 Newtonian Reflector Astrograph
  • quick-collimation cap is included.
  • distance is 92.4mm from the 2″ drawtube collar. Weighs 33 lbs., 12 oz.
Bower 500mm f/8 Manual Focus Telephoto T-Mount Lens
  • High-power 500mm telephoto focal length
  • Includes T-mount adapter for digital and 35mm Canon EOS SLR cameras
  • High index, low-dispersion multi-coated optical glass to reduce flare
Celestron 8 inch EdgeHD Ota Optical Tube
  • 8″ f/10 (2032mm) Edge HD with Starbright XLT coatings
  • 9×50 optical finderscope
  • 40mm Plossl eyepiece
Celestron – Inspire 100AZ Refractor Telescope
  • Inspire 100az Refractor Telescope
Cassini 1000mm x 120mm Reflector Telescope Smartphone Adapter
  • 1000 mm X 120 mm
Celestron CGX 1100 Rowe-Ackermann Schmidt Astrograph Telescope 12060
  • 11 inch
Celestron 36 cm Rasa Rowe-Ackermann Schmidt Astrograph Ota – 91077
  • 14″ / 2.2
Sky Watcher 150mm Esprit Ed Triplet Apo Refractor
  • 150 mm

1. Sky-Watcher Evostar 100ED / ProED 100mm Doublet Apo Refractor

Sky-Watcher Evostar 100ED / ProED 100mm Doublet Apo Refractor

  • 100 mm APO Refractor with ED Schott glass, 900 mm focal length f/9, Dual-speed 2 inch Crayford-type focuser with 1.25 inch adaptor.
  • 20mm and 5mm 1.25 inch eyepieces, 8×50 RA viewfinder, 2 inch dielectric diagonal.
  • Tube-ring attachment hardware, Aluminum carry case.
  • Sky-Watcher offers one of the most extensive lines of ed-Apochromatic refractors in the world.

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Sold By Price
Amazon.com
OPT Telescopes
Adorama
Mike’s Camera

Product Details

Specifications

Details
Optical Design ED Doublet
Lens Coatings Fully Multi-Coated
Glass Type BK7/FPL-53(ED)
True Aperture (mm) 100
Primary Aperture (mm) 100

2. Orion AstroView 6 Equatorial Reflector Telescope

Orion AstroView 6 Equatorial Reflector Telescope

  • Reflector Telescope.
  • Treat yourself, your friends, and your family to some wondrous evenings under the stars with the Orion AstroView 6 Equatorial Reflector Telescope!

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Sold By Price
Amazon.com – Seller
Orion Telescopes & Binoculars

Product Details

Specifications

Details
Package Dimensions 39 x 18.5 x 12 inches
Country of Origin China

Reviews From Real Customers

tomorrow from Mars
Bobalooey2001
Richie the Hat

3. Sky Watcher ProED 80mm Doublet Apo Refractor Telescope

Sky Watcher ProED 80mm Doublet Apo Refractor Telescope

  • 80 mm

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Amazon.com
OPT Telescopes
High Point Scientific
Adorama

Product Details

Specifications

Details
Telescope Series Sky-Watcher Evostar Pro ED APO
Focal Ratio f/7.5
Optical Design Refractor
Telescope Aperture 80mm (3.15″)
Telescope Mount Type No Mount – OTA Only

4. Zhumell – 12-Inch Dobsonian Reflector Telescope – Large Aperture for Crisp, Bright Images – Solid Base Construction with Handle for Easy Transport –

Zhumell – 12-Inch Dobsonian Reflector Telescope – Large Aperture for Crisp, Bright Images – Solid Base Construction with Handle for Easy Transport –

  • 12 Inch

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Sold By Price
Amazon.com – Seller

Product Details

Specifications

Details
Package Dimensions 60 x 19 x 18 inches
Batteries 1 LR44 batteries required. (included)
Is Discontinued By Manufacturer No
Country of Origin Taiwan

Reviews From Real Customers

Benjamin B.
Jeffrey B.
telescopesplus.com

5. Sky-Watcher Evostar 72 Apo Refractor

Sky-Watcher Evostar 72 Apo Refractor

  • PORTABLE TRAVEL SIZE: Using a compact design, this refractor is easy to transport and lightweight to support, making it the perfect travel companion.
  • 10:1 DUAL-SPEED FOCUSER: No matter the eyepiece or camera, finding focus is a breeze with this 10:1 dual-speed Crayford-style focuser.
  • EVERYTHING YOU NEED: The EvoStar 72 comes complete with an aluminum case, tube rings, and a Vixen-style dovetail.

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Amazon.com
B&H Photo-Video-Audio
OPT Telescopes
High Point Scientific

Product Details

Specifications

Details
Optical Design ED Doublet
Lens Coatings Fully Multi-Coated
True Aperture (mm) 72
Primary Aperture (mm) 72
F/Ratio 5.9
Focal Length (mm) 420
Dawes Limit 1.61
Rayleigh Limit 1.94
Limiting Mag 11.7
Minimum Magnification 10
Maximum Magnification 142
Focuser 2″ Dual Speed Crayford
OTA Length (Retract/Ext.) 16.5″
OTA Outer Diameter 3.5″
OTA Weight (with accessories) 4.3
Mounting Accessories Rings/V-Rail
Included Case Yes
Corrector No (optional)

Reviews From Real Customers

Connor K.
Y. P.

6. Rokinon 135mm F1.8 AF Full Frame Auto Focus Telephoto Lens for Sony E Mount Cameras

Rokinon 135mm F1.8 AF Full Frame Auto Focus Telephoto Lens for Sony E Mount Cameras

  • Superb resolution and light in weight with the newly designed optical system.
  • Ultra-precision Aspherical lens offering a soft and beautiful bokeh.
  • Focus Range Limiter useful for shooting portraits and close-ups.
  • Optimized function for astrophotography – Astro-Focus Mode and LED index Excellent Expression of F1.

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Sold By Price
Amazon.com
eBay
Walmart – Beach Camera
B&H Photo Video Audio

Product Details

Specifications

Details
Aperture Range F1.8 ~ 22
Lens Optical Construction 13 Elements in 11 Groups
Special Elements 1 U-ASP, 3 HR, 3 ED
Coating UMC
Minimum Focusing Distance 2.26′ (69cm)

Reviews From Real Customers

Boogle

7. Celestron 11″ Rowe-Ackermann Schmidt Astrograph V2 Ota

Celestron 11

  • ** Due Oct 2022.
  • Fast, wide-field 11” f/2.2 optical design with rare-earth glass for images free of false color, coma, and field curvature.
  • New Ultra-Stable Focus System (USFS) minimizes focus shift and mirror flop.
  • Integrated air-cooling system features a quiet, high-output 12V MagLev fan and vents with mesh filters to prevent dust ingress.
  • Common camera adapters (T-thread and M48) included for easy attachment to popular CCD and DSLR cameras.

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Sold By Price
Amazon
Walmart – Atlanta Hobby
OPT Telescopes
High Point Scientific

Product Details

Specifications

Details
Technology StarBright XLT
Optical Design Rowe-Ackermann Schmidt Astrograph
Aperture 279 mm
Focal Length 620mm
Focal Ration F/2.22

Reviews From Real Customers

Robert M.
Highpoint Scientific
Steven Y.

8. Sky Watcher 6in. Traditional Dobsonian Telescope

Sky Watcher 6in. Traditional Dobsonian Telescope

  • 6 in

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Amazon
OPT Telescopes
High Point Scientific
Adorama

Product Details

Specifications

Details
Optical Design Newtonian
Mirror Coatings 94% Aluminum
Glass Type Borosilicate
Primary Aperture (mm) 152
F/Ratio 7.9

Reviews From Real Customers

Louis
RubenBorges

9. Sigma 200-500mm f/2.8 Apo EX DG for Sigma

Sigma 200-500mm f/2.8 Apo EX DG for Sigma

  • ELD and SLD glass
  • HSM (Hyper Sonic Motor)
  • Internal focusing and internal zooming
  • Lens hood and rear filter system
  • Dedicated battery power

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Amazon
Adorama
Full Compass Systems

Product Details

Specifications

Details
Length 2.4 ft
Diameter 9.3 in
Weight 34.61 lbs
Type Telephoto zoom lens
Special Functions Tele, zoom

10. Celestron SkyProdigy 130mm Reflector Telescope

Celestron SkyProdigy 130mm Reflector Telescope

  • 307×130

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Amazon
B&H Photo Video Audio
OPT Telescopes
High Point Scientific

Product Details

Specifications

Details
Manufacturer Part Number 31153
Product Line SkyProdigy
Product Model 31153
Product Name SkyProdigy 31153 307×130 Telescope
Product Type Telescope

Reviews From Real Customers

Paul-Gabriel
Lanke
SkyScoper77

11. Tamron SP AF 17-50mm f/2.8 XR di II LD [IF] Lens for Nikon

Tamron SP AF 17-50mm f/2.8 XR di II LD [IF] Lens for Nikon

  • Optimized for Digital SLR.
  • Enhanced Peripheral Illumination.
  • Internal Surface Coating to Reduce Ghosting and Flare.
  • Zoom Lock Mechanism.
  • The Zoom Lock prevents unwanted barrel extension when carrying the lens/camera combination.

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Amazon
eBay
B&H Photo Video Used
MPB

Product Details

Specifications

Details
Length 3.2 in
Diameter 2.9 in
Weight 15.17 oz
Type Zoom lens
Special Functions Zoom

Reviews From Real Customers

mmn357157
chrndz97
sdw1031

12. Orion 10″ f/4 Newtonian Reflector Astrograph

Orion 10

  • quick-collimation cap is included.
  • distance is 92.4mm from the 2″ drawtube collar. Weighs 33 lbs., 12 oz.

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Amazon
Orion Telescopes & Binoculars

Product Details

Reviews From Real Customers

Free Bird

13. Bower 500mm f/8 Manual Focus Telephoto T-Mount Lens

Bower 500mm f/8 Manual Focus Telephoto T-Mount Lens

  • High-power 500mm telephoto focal length
  • Includes T-mount adapter for digital and 35mm Canon EOS SLR cameras
  • High index, low-dispersion multi-coated optical glass to reduce flare
  • Minimum focusing distance of 33 feet
  • Filter thread: 67mm

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Amazon
eBay
Walmart
B&H Photo-Video-Audio

Product Details

Specifications

Details
Length 1 ft
Diameter 2.8 in
Weight 1.41 lbs
Type Telephoto lens
Special Functions Tele

Reviews From Real Customers

Hon

14. Celestron 8 inch EdgeHD Ota Optical Tube

Celestron 8 inch EdgeHD Ota Optical Tube

  • 8″ f/10 (2032mm) Edge HD with Starbright XLT coatings
  • 9×50 optical finderscope
  • 40mm Plossl eyepiece
  • 1.25″ visual back and star diagonal
  • CGE mounting bar (Losmandy profile/wide)

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Amazon
B&H Photo-Video-Audio
High Point Scientific
Adorama

Product Details

Specifications

Details
Optical Design EdgeHD
Focal Length 2032 mm (80″)
Focal Ratio 10
Magnification of Eyepiece 1 51x
Finderscope 9×50

Reviews From Real Customers

jeff m.
CLEMENS

15. Celestron – Inspire 100AZ Refractor Telescope

Celestron - Inspire 100AZ Refractor Telescope

  • Inspire 100az Refractor Telescope

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Walmart
B&H Photo-Video-Audio
OPT Telescopes

Product Details

Specifications

Details
Product Type Telescope
Telescope Class Refractor
Max Magnification 241 x
Telescope Aperture 100 mm
Telescope Focal Length 660 mm

Reviews From Real Customers

Ramanraman

16. Cassini 1000mm x 120mm Reflector Telescope Smartphone Adapter

Cassini 1000mm x 120mm Reflector Telescope Smartphone Adapter

  • 1000 mm X 120 mm

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Walmart – Cosmo Brands, Inc. – Cassini & Galileo Optics
Best Buy
BJ’s Wholesale Club

Product Details

Specifications

Details
Objective Lens Diameter 120 millimeters
Computerized Star Locator Included No
Eyepieces Included 10mm, 25mm, 3XBarlow
Erect-Image Optics Included No
Lens Cap Included Yes

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Tanya
DawnB
westcore

17. Celestron CGX 1100 Rowe-Ackermann Schmidt Astrograph Telescope 12060

Celestron CGX 1100 Rowe-Ackermann Schmidt Astrograph Telescope 12060

  • 11 inch

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Walmart – Atlanta Hobby
High Point Scientific
Adorama
Orange County Telescope

Product Details

Specifications

Details
Aperture 279 mm (11″)
Back Focus 72.8mm
Camera/Eyepiece Connection Male T—Thread (M42x0.75)
Corrected Image Circle 43.3mm
Dawes Limit 0.42 arcseconds

Reviews From Real Customers

Kelvin J.

18. Celestron 36 cm Rasa Rowe-Ackermann Schmidt Astrograph Ota – 91077

Celestron 36 cm Rasa Rowe-Ackermann Schmidt Astrograph Ota - 91077

  • 14″ / 2.2

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Adorama
OpticsPlanet.com

Product Details

Specifications

Details
Optical Design Rowe-Ackermann Schmidt Astrograph
Aperture 355.6 mm
Focal Length 790mm
Focal Ration 2.22
Central obstruction diameter 158 mm (44% of aperture diameter)

19. William Optics ZenithStar 73mm f/5.9 Full Frame Imaging Apo Refractor with Soft Case – Red #A-Z73IIIRD | Agena AstroProducts

William Optics ZenithStar 73mm f/5.9 Full Frame Imaging Apo Refractor with Soft Case - Red #A-Z73IIIRD | Agena AstroProducts

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Agena AstroProducts

Product Details

Specifications

Details
Focal Length 430mm
Diameter 73mm
Aperture f/5.9
Camera Format APS-C, Full Frame
Focuser 2.5″ R&P

Reviews From Real Customers

Stu A.
Richard L.
Dwight W.

20. Sky Watcher 150mm Esprit Ed Triplet Apo Refractor

Sky Watcher 150mm Esprit Ed Triplet Apo Refractor

  • 150 mm

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B&H Photo Video Audio
High Point Scientific
Adorama
OpticsPlanet.com

Product Details

Specifications

Details
Focal Length 1050 mm
Image Circle 43mm
OTA Weight 32 lb.
Telescope Series Sky-Watcher Esprit
Focal Ratio f/7

Reviews From Real Customers

MARK
Alan L.
optcorp.com

Conclusion

The focal length of a telescope is an important factor in astrophotography. A longer focal length will allow you to capture more light from distant objects, but it will also require a larger telescope.

A shorter focal length will allow you to capture less light from distant objects, but it will also require a smaller telescope. The best focal length for astrophotography depends on the type of objects you want to photograph.

If you want to photograph distant galaxies, a longer focal length will be better. If you want to photograph closer objects, such as the moon or planets, a shorter focal length will be better.

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