William Optics Zenithstar 81 APO
Colour: GoldColour: RedColour: Blue

William Optics Zenithstar 81 APO

£799.00✓ 2 year warranty


2x in stock shipped 1-2 working days

About this product

Model:  wo_zs81_rd
Part Number:  A-Z81RD

The NEW William Optics Zenithstar 81 APO features an air-spaced doublet lens with an Ohara FPL-53 ED glass element in a CNC machined ultra high precision lens cell with fully multi-coated optics for high resolution, high contrast images virtually free of false-colour. 

Versatile f/6.9 native focal ratio or f/5.5 when used with 0.8x flattener / reducer (available separately).

Supplied with Dualside dovetail (Vixen fit one side and Arca-Swiss on the other side), mounting rings and  a new carry handle bar that a guidescope can slide into.

CNC machined aluminium for a superior fit and finish. 

Heavy duty, 1:10 dual speed, 2.5" Rack and Pinion focuser.

Available in Blue, Red or Gold anodised.  


  • 81mm f/6.9 Doublet air-spaced APO
  • CNC machined ultra-high precision lens cell
  • FPL-53 ED glass element for enhanced colour correction
  • 2.5 inch Heavy Duty, dual-speed Rack and Pinion focuser
  • 0.8x Reducer / Flattener available separately
  • Innovative Bahtinov mask cover included!
  • Supplied with mounting rings, CNC carry handle, Dual side Vixen/Arca Swiss dovetail bar and Bahtinov mask cover

Field of View Simulator

What's in the box

  • Telescope OTA
  • Mounting Rings
  • CNC made Carry Handle
  • Dual Vixen / Arca Swiss Dovetail
  • Bahtinov Mask Cover


Aperture81 mm
Focal Ratiof/6.9
Focal Length559 mm
Image CircleFull Frame with Flat 6AIII
Objective TypeED Doublet, Air Spaced,
Fully Multi-Coated, SMC coating.
Lens ShadeRetractable
Tube Weight3.53kg - Including dovetail & rings
Tube length460mm Retracted, 560mm Extended
Interchangable T Mounts:Canon EF, Nikon F, Sony E, Pentax, Micro Four Thirds

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Q1. Does the William Optics Zenithstar 81mm include a soft carry case?

Iit does include a soft carry case.

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