Askar Apochromatic refractor AP 71/490 Flat-Field 71F OTA (83301)

The Askar 71F (‘Flat Field’) is a compact quadruplet astrograph featuring a 71 mm aperture, 490 mm focal length, and a native aperture ratio of f/6.9. It uses a quadruple apochromatic lens with an air gap and includes an ED element to effectively reduce chromatic aberration. The Askar 71F is capable of full-frame imaging up to 44 mm, delivering excellent star quality even at the edge of the field. The integrated flattener eliminates the need for additional correctors.

The package includes a viewfinder shoe, carrying handle, photo adaptors, two eyepieces, a Vixen/GP prism rail with a photo tripod connection, and a test certificate, providing everything needed for convenient use.

Specifications

• Optical Design: Refractor, apochromat

• Aperture: 71 mm

• Focal Length: 490 mm

• Aperture Ratio: f/6.9

• Resolving Capacity: 1.94

• Limiting Magnitude: 12.3

• Light Gathering Capacity: 100

• Maximum Useful Magnification: 142x

• Lens Design: Quadruplet

• Tube Weight: 3.0 kg

• Dew Cap Diameter: 93 mm

• Fully Corrected Field: 44 mm

Focuser

• Type: Rack and pinion

• Eyepiece Connection: 2"

• Motorized: No

• Ring Clamp: Yes

• Gear Reduction: 1:10 fine focusing

• Adjustment Range: 111 mm

• Tilting Adaptor: No

• Rotating: Yes

Mount and Accessories

• Mount Type: OTA (no mount included)

• Dew Shield: Yes

• Deviating Optics: Amici prism, 1.25", 45°

• Corrector: Integrated

• Prism Rail: Vixen-Style

• Carrying Handle: Yes

• Extension Tubes: Yes

• Transport Case: Not included

• Carry Case: Not included

• Finder Base: Vixen/Skywatcher Level

• Eyepiece Adaptor: 1.25" & 2"

• Tube Clamps: Yes

• Test Certificate: Included

• Eyepieces Included: 8 mm and 20 mm (1.25")

General

• Variant Name: Flat-Field

• Special Recommendation: Yes

Area of Application

• Astrophotography: Yes (very good)

• Moon & Planets: Yes

• Nebulae & Galaxies: Yes

• Nature Observation: No

• Sun: Only with appropriate solar filter

Recommended For

• Beginners: No

• Advanced Users: Yes

• Observatories: No