Askar- 71F f/6.9 Flat Field Quadruplet APO Optical Tube Assembly

SKU
ASK-71F
$599.00
Availability : More On The Way
Free Shipping Available

The Askar 71F is an exceptional choice for those seeking affordability in a quadruplet APO optical tube assembly. It boasts a 71mm aperture, 490mm focal length, and operates at a native focal ratio of f/6.9. Utilizing a quadruplet air-spaced ED design, it excels at reducing chromatic aberrations by evenly refracting all colors. This results in crisp and precise views and images, supported by a 44mm image circle capable of accommodating full-frame sensors.

Askar- 71F f/6.9 Flat Field Quadruplet APO Optical Tube Assembly

71F f/6.9 Flat Field Quadruplet APO Features

  • The Askar 71F is an affordable quaduplet APO optical tube assembly.
  • OTA has a 71mm aperture, 490mm focal length, and f/6.9 native focal ratio.
  • Quadruplet air-spaced ED design minimizes chromatic aberrations
  • 71F has an image circle of 44mm, supporting up to full frame 35mm sensors.
  • Built-in flattening capabilities for enhanced image quality to remove field curvature.
  • No need for manual backfocus calculations.
  • Telescope tube weighs only 2.5kg (3kg with mounting rings and dovetail).
  • Suitable for both visual observers and astrophotographers
  • Includes 8mm and 20mm eyepieces, providing 60x and 25x magnifications respectively.
  • 1.25" 45° prism ensures correct orientation of photos and views.
  • Extension tube with M48x0.75 and M54x0.75 adapters for versatile camera connections.
  • Retractable dew shield reduces optical tube length and minimizes light scatter.
  • Handlebar features a finder base slot for convenience.
  • Two finder bases on each side of the focuser for additional accessory attachment if needed.
  • Includes a Rack and Pinion 2.4" focuser with 1:10 fine adjustment and 360° field rotator at the rear.
  • Includes a 230mm V style dovetail with 1/4 and 3/8 screw holes for tripod attachment

Quadruplet Apochromatic Lens Design with Flattening Built In

The Askar 71F stands out as a very affordable quadruplet APO optical tube assembly, featuring a 71mm aperture, 490mm focal length and a native focal ratio of f/6.9. As a quadruplet air spaced ED design, it is outstanding at removing chromatic aberrations by ensuring equal refraction of all colors, thus rendering sharp and pinpointed views and images with a 44mm image circle, large enough to support sensors up to full frame.

To further enhance image quality, the Askar 71F is built with flattening capabilities to remove field curvature and remove the hustle of manual backfocus calculations and endless adapters.

Great for Visual Astronomers and Imagers Alike

The Askar 71F is designed with portability as a guarantee, weighing only 2.5 kg (3kg with mounting rings and dovetail). It serves as a great tool for visual observers and astrophotographers alike with its razor sharp optics. The Askar 71F comes with 8mm and 20mm eyepieces and a 1.25" 45° prism, resulting in 60x and 25x magnifications respectively. The diagonal prism results in correct oriented photos and views.

Includes Adapters for Imaging

Included with the Askar 71F is an extension tube with M48x0.75 and M54x0.75 adapters to connect to a wide variety of cameras. A 2" filter thread is also included.

Handle Bar, Tube Rings and Rack and Pinion Focuser

The Askar 71F dew shield is retractable, effectively reducing optical tube length for increased portability and a further benefit of removing light scatter with the matte paint finish on the inside.

The handlebar includes a finder base slot while two finder bases are located on each sides of the focuser for easier use and to attach other accessories if needed. The focuser is a Rack and Pinion 2.4" with 1:10 fine adjustment and a 360° field rotator at its rear.

Last but not least, the Askar 71F comes with a 230mm V style dovetail with 1/4 and 3/8 screw holes to attach to tripods.

More Information
Brand Askar
Free Shipping Free Shipping Available
Aperture 71mm
Case Included No
Focal Length 490mm
Focal Ratio f/6.9
Focus Type Dual Speed Rack and Pinion 2.4"
Image Circle 44mm
Optical Tube Length 372.5mm standard to 473.4mm with 1.25" adapter and dew shield stretched
In The Box
  • Askar 71F Optical Tube Assembly
  • Pair of tube rings
  • Handle
  • Vixen 230mm dovetail plate
  • Set of photographic adapters
  • 1.25" 45° erecting prism
  • 8mm eyepiece
  • 20mm eyepiece
  • Askar 71F Optical Tube Assembly
  • Pair of tube rings
  • Handle
  • Vixen 230mm dovetail plate
  • Set of photographic adapters
  • 1.25" 45° erecting prism
  • 8mm eyepiece
  • 20mm eyepiece
Write Your Own Review
You're reviewing:Askar- 71F f/6.9 Flat Field Quadruplet APO Optical Tube Assembly
Your Rating
Shopping Guide Shopping Guide