William Optics Zenithstar 61 II APO
William Optics Zenithstar 61 II APOWilliam Optics Zenithstar 61 II APOWilliam Optics Zenithstar 61 II APO
William Optics Zenithstar 61 II APOWilliam Optics Zenithstar 61 II APO

William Optics Zenithstar 61 II APO

£499.00✓ 2 year warranty


2x in stock shipped 1-2 working days

About this product

Model:  wo_zs61_ii_gd
Part Number:  A-Z61IIGD

Latest 2020 model with Bahtinov Mask cap, CNC saddle handle, longer dovetail & Soft Case. 

The William Optics Zenithstar 61 II APO features an air-spaced doublet lens with fully multi-coated optics and an Ohara FPL-53 ED glass element for sharp, high contrast images virtually free of false-colour. 

Provides high resolution images when used for astrophotography or wildlife photography and is a convenient ultra-portable telescope for visual astronomy (think binocular astronomy targets).  

The fast f/5.9 focal ratio and compact size make it ideal for convenient wide field astrophotography or piggybacking. 

Convenient rotatable L mounting bracket for easy framing of target. 

CNC machined aluminium for a superior fit and finish. 

Dual speed 2" 1:10 R&P focuser.

Available in Red, Gold or Space Grey anodised.  

Ohara FPL-53 vs FPL-51 ED Glass

The dispersion properties of ED and SD glass elements are important in determining the overall colour correction. The abbe index is used to quantify the 'partial dispersion' of a particular glass. Pure Fluorite offers the highest partial dispersion at around 94.99 V, Ohara FPL-53 glass is very close to Fluorite at 94.93 V and is often referred to as Synthetic Fluorite.  FPL-53 is also noticeably better than Ohara's lower spec' FPL-51 glass which offers an abbe index of 81.54 V.


  • 61mm diameter, 360mm focal length, f/5.9
  • Two element APO design using FPL-53 glass
  • 2" R&P Focuser for smooth, stable and reliable focusing
  • Integrated CAT Handle bar with Vixen-style Finder Shoe Clamp - great for guide scopes!
  • Integrated Bahtinov Mask for easy, precise focusing
  • CNC clamp ring with saddle handle bar and longer dovetail makes balancing and mounting much easier and more rigid
  • Soft padded case
  • Tube length: 245mm retracted / 315mm extended
  • Tube Weight: 2.2kg

Telescope Field of View Simulator

What's in the box

  • ZenithStar 61 OTA
  • 2" to 1.25" Adapter
  • OTA Mounting RIng
  • Cat Handle / Finderscope Clamp
  • Vixen-style Dovetail
  • Soft padded case


Aperture 61mm
Focal Ratio F/5.9
Focal Length 360 mm
Objective Type Air-spaced doublet with fully SMC multicoated optics and Ohara FPL 53 ED element. 
Image Circle Z61 Φ 41mm / Z61 with Flat 61 Φ 43mm
Limiting Magnitude 10
Lens Shade Retractable
Focuser 50.8mm (2") R&P Focuser with 1:10 Dual Speed micro-focuser, 75 mm Focuser Travel Length
1.25" Adapter Compression Rings
Mount Vixen-style Dovetail
Field Stops Baffles
Tube Length 245 mm Fully Retracted
315 mm Fully Extended
Tube Weight 2.2kg

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William Optics Finder Bracket
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