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 APOWilliam Optics Zenithstar 61 II APO

William Optics Zenithstar 61 II APO

  (14 Reviews)
✓ 2 year warranty


3x in stock shipped 1-2 working days

About this product

Model:  wo_zs61_ii_gd
Part Number:  A-Z61IIGD

This latest model has a 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. 

It provides high-resolution images 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 the 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
  • The integrated CAT Handle with Vixen-style Finder Shoe Clamp is 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

Customer reviews

Average Rating (14 Reviews):  
Write a Review and share your opinions!

Rating (max 5):  
Great service
01 January 2023  | 

The quality of this scope and field flattener is exactly what you'd expect from a company like William Optics. Not had chance to use it because of the weather. My biggest thank you is to First Light Optics. This is the ONLY company I've dealt with in the past 10 or so years that has delivered the kit on the day it was promised. I live on the Isle of Man so getting stuff here has always comes with delays. Not so with FLO!! Other companies should take not.

Rating (max 5):  
Excellent Value and Service
26 November 2022  | 

Excellent value and service as always from the team at FLO

Rating (max 5):  
Excellent telescope
12 November 2022  | 

By far, the best telescope I've ever owned. For better or for worse, once you own a William Optics telescope, you'll hardly want anything less.

Rating (max 5):  
My introduction to "a real scope"
31 August 2022  | 

It has all been said before, a superb quality small and portable scope, extremely well made and will certainly remain under my ownership for many years to come. Excellent and speedy customer service by FLO.

Rating (max 5):  
WO 61
15 August 2022  | 

Brought as a part of grab & go setup
I'll keep it simple as the reviews already sum it,
Stunning build quality, looks, and optics and delivery, and customer service, thank you Alex for very detailed accurate advice, 😁👍

Rating (max 5):  
Superb quality
02 May 2022  | 

Well what can I say that hasn't already been said, the quality of construction in this price range is second to none. I managed a few hours of cloudless skies with this shortly after super quick delivery and was astounded by the lack of CA, perfect white pin pricks of light without any signs of colour segregation. Quiet heavy for such a small scope but this reinforces the quality of construction. Only slight grumble is that it didn't come with a finderscope shoe, but this has been ordered now so shouldn't wait too long.

Rating (max 5):  
17 June 2021  | 

Amazing quality, and an awesome scope. ,really all the reviews that have gone before me say it all .
William Optics you have done it again.

Rating (max 5):  
Nice little scope
05 June 2021  | 

This is a very useable quality scope. I only bought it to pass the time until my SCT order from February arrives. Itís my first owned scope so I canít compare to others but all the William Optics gear I bought is high quality stuff.

Rating (max 5):  
Seemingly indestructible, ultra portable telescope, with excellent image quality
13 April 2021  | 

I bought this as a portable field scope and as a guide scope for my 8" EdgeHD, along with the 61ii flattener. The build quality is excellent. Within the first few weeks of purchasing this scope I managed to drop it 1 metre onto gravel after failing to secure it properly to the main OTA. This was quite traumatic to watch. Astonishingly the scope was 99.9% unscathed (just a minor scuff on the cap) - optics appear fine - in fact I have recently used this for wide field imaging and I'm extremely impressed with the results. Awesome product!

Rating (max 5):  
High Quality Telescope
08 April 2021  | 

This item was promptly delivered by First Light Optics and, straight out of the box, it is obvious that this is made to the highest of standards. It feels really solid and well constructed from high quality materials. William Optics have carefully considered the needs of photographers in the design, and the focussing system is a treat to use. I can not recommend this too highly and look forward to great results from it whenever clear skies permit.

Read all 14 customer reviews...


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