William Optics ZenithStar 71 ED Doublet Refractor with Flattener

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William Optics ZenithStar 71 ED Doublet Refractor with Flattener
Item # WO-A-Z71A-P
1 Questions(s)

Scheduled Delivery

  • The William Optics ZenithStar 71mm f/5.9 Refractor is small but mighty! Weighing only 6 lb. and just a tad over a foot long, the ZS71 can go anywhere, even under your seat on a plane.
  • The optics of the Zenith Star 71 are made with Ohara glass from Japan, and they are fully-multi-coated for sharpness, clarity, and contrast.
  • The lens cell, powder-coated white optical tube assembly, and dew shield are all CNC-machined.
  • A 2" rack and pinion 10:1 dual-speed focuser is super sturdy and will not slip when locked down, even with heavier cameras attached.
  • This package comes with a 2" reducer/flattener. It will reduce the focal ratio of your ZS71 by 0.8X.
  • Accessories shown in the photo at left are sold separately.


William Optics ZenithStar 71 ED Doublet Telescope

The ZenithStar 71 ED from William Optics is a super portable telescope with quality optics. The 71mm ED air-spaced doublet is made with Ohara glass from Japan, and is fully multi-coated with STM super high transmission coatings for high contrast, sharp views. The optics are mounted in a CNC machined precision lens cell to keep them perfectly aligned.

The CNC-machined aluminum optical tube assembly of the ZS71 comes fully baffled to prevent light bounce and a retractable dew shield to further increase contrast. The William Optics 2" rotatable rack and pinion focuser included with this scope allows for 1:10 course and fine focusing. Its mechanical strength makes for extremely smooth movements and no backlash. The focuser can be locked down and will not flex or slip, even with a heavy camera on the back, and the tension is adjustable so that you can set it to accommodate accessories of different weights. The draw tube with graduated scale has a travel length of 80mm.

This special ZS71 package comes with a 2" reducer/field flattener made of Ohara optical glass. It reduces the focal ratio by a factor of 0.8X, and does a great job of flattening the field, The Flat 6 is a fully multi-coated doublet that provides good illumination for APS sized sensors. An easy-to-use rotating t-adapter will accept any standard 35mm t-ring.

The William Optics ZenithStar 71 is the perfect telescope for the EAZY-T Alt-Azimuth Mount. It even slides directly onto the mount without the need for a dovetail.

William Optics ZenithStar 71 ED Doublet Refractor Specifications


  • Aperture: 71mm
  • Focal Ratio: F/5.9
  • Focal Length: 418 mm
  • Objective Type: ED Doublet, Air Spaced, Fully Multi Coated
  • Resolving Power: 1.58"
  • Limiting Magnitude: 11
  • Lens Shade: Retractable
  • Focuser: 2" Rack & Pinion 360º Rotatable 1:10 Dual Speed Focuser
  • Reducer/Flattener: 2" doublet with 0.8X reduction.
  • Tube Travel Length: 80 mm (3.2")
  • Focuser Adapter: 1.25" Adapter with Brass Compression Rings
  • Mount Type: Integrated L Bracket (fits SmartEQ mount)
  • Field Stops: Baffles
  • Tube Diameter: 93 mm (3.66")
  • Tube Length: 310 mm Fully Retracted, 355 mm Fully Extended
  • Tube Weight: 6 lb. (2.7 kg)
Additional Information

Additional Information

Manufacturer William Optics
Telescope Series William Optics ZenithStar
Optical Design Refractor - Achromatic with ED Glass
Mount Type None - Optical Tube Only
Warranty 2 Year Warranty
Telescope Aperture 71mm (2.79")
Telescope Focal Length 418mm
Telescope Focal Ratio f/5.9
Optical Tube Outer Diameter 93 mm (3.66")
Length of Optical Tube 310 mm Fully Retracted, 355 mm Fully Extended
Tube Color or Finish Gloss White
Dew Shield Included? Yes
Limiting Stellar Magnitude 11
Finder Included None
Total Telescope Weight 6 lb.
Included Items

Included Items

  • William Optics 71mm ZenithStar ED
  • 2" Rack & Pinion Dual-Speed, 10:1 Focuser, fully rotatable
  • 2" 0.8X Reducer/Field Flattener
  • 1.25" Adapter
  • Red L-Bracket
  • Red Metal Lens Cap
Questions & Answers

Product Questions

Would this be easily mounted on a Meade 16" SCT tube? What does "scheduled delivery" mean?
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