William Optics Gran Turismo 81mm ED APO Refractor

106,500.00 excl. 18% GST

  • Focal Length: 478mm
  • Diameter: 81 mm
  • Aperture: €/5.9
  • Camera Format: APS-C, Full Frame
  • Focuser: 2.5″ R&P focuser
  • Image Circle: > Full Frame
  • Recommended Flattener: FLAT 6A IlI
  • Tube Length:
  • 390 mm (Fully Retracted)
  • 460 mm (Fully Extended)
  • Tube Weight: 3.9 kg
  • InterchangableT-Mount:
  • Canon EF, Nikon F
  • Sony E, Pentax,
  • Micro four Thirds, Fuji FX

The William Optics Gran Turismo 81 Triplet is designed to deliver incredible image quality in a compact package. Sitting at a respectable ratio of f/5.9, this FPL53 triplet is well-balanced in light-gathering power

This is no ordinary refractor.

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

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. Strong and nice look!

Bahtinov Mask

World first built in clear Bahtinov mask!

Flattener – (Not Included 2019 All New Adjustable Flat 6A III (T-mount not included))

This very elegant 2″ reducer/field flattener has been designed to optimize the flat-field imaging performance of William Optics F/6 to F7.5 ratio refactors. WO Flat 6AIII will provide good illumination and flat field across 97% of full frame sized sensors.

Superb Finish

William Optics polished anodized finish.

All internal surfaces threaded and blackened to prevent reflections.

Easy to Use

Will accept any standard 48mm wide T-ring for your camera. Not compatible with smaller 42mm T rings.

Deep Sky Imaging with the Gran Turismo 81 APO

If you are new to deep sky astrophotography but have dabbled in tracked night sky shots including the Milky Way – this is likely the best possible next step for you.

Ultra-Portable Telescope

It is often said, that the best telescope is the one you use most often. With a retracted length of 392mm and convenient mounting options, you’ll have no excuse not to deploy the GT81 for a night of deep-sky astrophotography on a moment’s notice.


William Optics uses high quality steel lens cells and FPL53 glass for WO triplet series (GT and FLT) – this combination is perfect for temperature compensation and will prevent pinched optics in cold weather conditions,

Before you store the telescope you have to uncover it and let the tube to stay open for sometime. After the telescope dry up, moisture will evaporate and it can be safely stored. You must store your telescope in a dry place with constant room temperature. Otherwise lens cell will rust and lens coating will be damaged by fungus.

Telescope Series William Optics GT
Focal Ratio f/5.9
Optical Design Refractor
Telescope Aperture 81mm (3.19″)
Telescope Mount Type No Mount – OTA Only
Type of Electronics OTA Only – No Electronics
Number of Refractor Elements 3 (Triplet)
Focal Length (mm) 478 mm
Focuser Style Rack & Pinion
Focuser Size 2.5″
Focuser Speed Dual Speed
Refractor OTA Length – Retracted (in.) 15.4″ (390 mm)
Telescope OTA Weight (lb.) 8.71 (3.95kg)


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