William Optics GT-81 - Checked & Tuned

William Optics GT-81 - Checked & Tuned
William Optics GT-81 - Checked & TunedWilliam Optics GT-81 - Checked & TunedWilliam Optics GT-81 - Checked & TunedWilliam Optics GT-81 - Checked & Tuned
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Model:  wo-gt-81-scope
Brand:  William Optics

ES Reid Checked Telescope

Es Reid is highly regarded in the optical industry so to ensure our refractors perform at their very best we send them to him for checking and, if necessary, tuning on his optical bench. 

Inevitably some telescopes require more time on the bench than others but we average the costs so this extra layer of quality control adds only £75 to the purchase price. 

A small price to pay for peace of mind.

You can order your telescope with confidence knowing it will have well figured optics, negligible false colour and spherical aberration, and no astigmatism (the bane of any optical system!). Star shapes will be round, not triangular, oval or egg-shaped!

You know it makes sense :-) 

Checked & tuned, for details see here

The William Optics GT-81 APO Triplet refractor features a 3-element f/5.9 objective with an Ohara FPL-53 extra-low-dispersion glass element for optimum colour correction and an upgraded 2-inch dual-speed Rack & Pinion focuser. 

The Hotech SCA Field Flattener is an excellent match for this telescope.  

The William Optics 0.8x focal reducer is also available to reduce the focal-ratio to a fast f4.72. 

An excellent choice for astrophotography!

Includes mounting bracket, carry handle, finder/guider rings and high quality soft carry case.




Focal Ratio


Focal Length


Objective Type

Triplet FPL-53 Air Spaced
Fully Multi-Coated, STM coatings

Tube Length

340mm Fully Retracted
400mm Fully Extended

Fitted with carry handle

Tube Weight


There are currently no specifications available for this product.

William Optics GT-81 - Checked & Tuned Questions & Answers

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Average Rating (3 Reviews):  
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Rating (max 5):  
Williams Optics GT81
Monday, 24 August 2015  | 

Not only is this scope brilliant for DSO's, One evening I decided to try it out on Jupiter I pushed the magnification up ad up till I had no shorter focal lengths beyond my Baader 5mm BGO. The image was crystal sharp with 5 of jupiters bands clearly visible.

Rating (max 5):  
Lovely Little Scope
Saturday, 28 February 2015  | 

Lovely little APO for widefield imaging.
Feels very sturdy and well made, Good build quality.
I like the R&P focuser, very smooth and sturdy with no mid-image slips.
It's reviewed well on t'internet, and didn't disappoint.

Rating (max 5):  
William Optics GT81
Saturday, 14 February 2015  | 

This scope is my third APO after a WO Megrez 90 and an Equinox ED120, and it doesn't dissapoint. I purchased it from FLO along with a Vixen Porta II, and the combination is perfectly suited to grab and go viewing, and well as to imaging on a suitable equatorial. The OTA is suprisingly heavy with a smooth focuser and useful carrying handle. I'm not sure I need the built in thermometer but it adds to the aesthetic of this diminuitive package. Great scope. A thing of beauty. Highly recomended.

A few of my first shots with the scope are on my website: www.jenhams.co.uk

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