Brand: , , ,

Gran Turismo 81 IV refracting telescope


The Gran Turismo 81 is a Three Element Designed APO refractor. Using FPL-53 glass this telescope provides excellent aberration correction.


Available on backorder

SKU: ASC5451 Categories: , , ,
Guaranteed Safe Checkout

Gran Turismo 81 IV refracting telescope (gold)

The Gran Turismo 81 is a Three Element Designed APO refracting telescope Optical Tube Assembly (OTA). Using FPL-53 glass this telescope provides excellent aberration correction. The smaller version of this refractor telescope can be found on this link here.

The William Optics Gran Turismo 81mm refracting telescope features a CNC machined optical tube with an immaculate white finish and Trim color of your choice. Internally, this refractor contains a 3-element objective using high-quality FPL-53 extra-low dispersion glass to reduce any secondary spectrum to an incredible extent. The three element apochromatic design and FPL-53 glass provide superior optical performance and excellent aberration correction. This 81mm OTA from William Optics comes with a 2.5″ Rack & Pinion Focuser, a camera angle rotator, CNC Handle Bar, Bahtinov Mask, Mounting Rings, and Dovetail. Mount this OTA package to a mount and tripod, and you are all set for a fantastic visual observation or imaging session.

William Optics has included a 2.5″ Rack & Pinion focuser to for smooth and stable focusing. The design ensures astrophotographers do not need to worry about image shifting. This focuser comes with 1:10 dual-speed and super smooth 360º rotation. William Optics has included two locking screws on angled positions for operations with heavy-duty payloads and a large aluminum knob with built-in thermometer. Attached to the 2.5″ R&P focuser is a WO camera angle rotator to help you get that perfect focus for beautiful celestial images. As an added bonus for focusing, William Optics has added the innovative Bahtinov mask cover.

With the William Optics CNC Handle Bar, this already portable refracting telescope has a sturdy handle to help carry the OTA around to your favorite gazing spot. Not only is this handle bar functional as a handle, it also acts a slide base for compatible guiding accessories as an astrograph telescope. This handle bar perfectly fits William Optics slide base 50mm guide rings and the WO UniGuide 50mm Guide Scope (both are not included).

Details and Features

2.5″ R&P Focuser

The 2.5″ R&P Focuser is smooth, stable, and reliable. No image shifting.


New Designed Rotator

William Optics designed camera angle rotator. Smooth and stable.


CNC Handle Bar

Made by CNC with anodizing.


Bahtinov Mask

Built-in clear Bahtinov mask



  • Triplet air-spaced objective (FPL-53) in adjustable CNC machined ultra high precision lens cell.
  • Extremely sharp refractor telescope.
  • Excellent color correction.
  • Each lens is Fully Multi-Coated with a special super-high transmission coating (STM Coating) on all surfaces.
  • This F/5.9 lens is ideal for astrophotography; a true astrograph telescope.
  • 2.5”R&P Focuser
  • 2.5”R&P Ultra robust focuser with 1:10 dual speed: a treat to use during astrophotography. Heavy duty: perfect for your accessories.
  • Simply Beautiful Finish
  • Pure William Optics quality fit and finish: powder-painted white CNC-machined aluminum tube, gold trim finish, retractable dewshield, dewshield cap.
  • Top quality anodizing.
  • Very compact for carrying on flights.

Attention to Details

  • 2″ & 1.25″ adapter included in the price.
  • Anti-marring brass compression rings.
  • 90mm mounting rings are optional.
  • 2-year warranty from William Optics.

Standard Package:

  • Telescope OTA with 2.5” R&P Focuser and with built-in camera rotator
  • New Vixen Dovetail Plate
  • Mounting Rings
  • New CNC Carry Handle Bar
  • Innovative Bahtinov Mask Cover (Patented)
  • Soft Carry Case
  • 2″ to 1.25″ Adapter
  • Soft Carry Bag
Weight7 kg
Dimensions45 × 35 × 23 cm


There are no reviews yet.

Only logged in customers who have purchased this product may leave a review.

Focal Length: 478mm

Diameter: 81 mm

Aperture: f/5.9

Camera Format: APS-C, Full Frame

Focuser: 2.5″ R&P focuser

Image Circle: > Full Frame

Recommended Flattener: FLAT 6A III

Tube Length: 390 mm (Fully Retracted) 460 mm (Fully Extended)

Tube Weight: 3.9 kg

Interchangable T-Vount: Canon EF, Nikon F Sony E, Pentax, Vicro four Thirds, Fuji FX

Shopping Cart
Astronomical Solutions Company

Add address

Scroll to Top

Having difficulty making your purchase? Don’t worry! fill Out the form below, and a real, friendly human being (No bots, we promise!) will swoop in to save the day. 🦸‍♂️🦸‍♀️

Or alternatively send a WhatsApp message to +968 7151 4492 and We will get back to you during working hours!


Let's have a chat