Agena AstroProducts Winter Sale

William Optics GTF81 81mm Apo Refractor with Built-In Flattener & DDG Focuser # A-F81GTA-DDG

Our Price: $1,128.00
Free shipping for this item in the US Click here for more info

Continental US Customers:
All items we sell ship for free within the Continental US. Shipping will be via the cheapest shipping method which will vary depending on the items in your order. During checkout, you may also be shown other optional faster shipping choices.

US Customers in Hawaii and Alaska:
Free shipping applies to almost all products. A few large telescopes and mounts are excluded from this free shipping offer. For these items, please contact us to obtain a shipping quote before you check out using the online shopping cart.

International Customers:
Free shipping does not apply to international orders. During check-out, you will be presented with several shipping choices and costs. However, the export of some items may be restricted outside the US due to size or manufacturer restrictions.

Out of Stock
Availability: Item has been discontinued and is no longer available.
Our Product ID: ZZT-ZZWO-GTF81-DDG
Manufacturer SKU: A-F81GTA-DDG
Item Can Ship: Worldwide
William Optics GTF81 81mm Apo Refractor with Built-In Flattener & DDG Focuser # A-F81GTA-DDG

More Views

  • William Optics GTF81 81mm Apo Refractor with Built-In Flattener & DDG Focuser # A-F81GTA-DDG
  • William Optics GTF81 81mm Apo Refractor with Built-In Flattener & DDG Focuser # A-F81GTA-DDG
  • William Optics GTF81 81mm Apo Refractor with Built-In Flattener & DDG Focuser # A-F81GTA-DDG
  • William Optics GTF81 81mm Apo Refractor with Built-In Flattener & DDG Focuser # A-F81GTA-DDG
  • William Optics GTF81 81mm Apo Refractor with Built-In Flattener & DDG Focuser # A-F81GTA-DDG
  • William Optics GTF81 81mm Apo Refractor with Built-In Flattener & DDG Focuser # A-F81GTA-DDG

Availability: Item has been discontinued and is no longer available.

Product Details

The stunning new William Optics Gran Turismo GTF 81 Apo is the new jewel of the apochromatic refractor world. From the pristine white finish on the CNC tube to the elegant dark red trim, this beauty has more than just good looks. This new GTF81 features a 3-element objective using high-quality FPL-53 extra-low dispersion glass that reduces any secondary spectrum to an unbelievable degree. But what makes this scope truly unique is the second optical component - a 2-element built-in ED field flattener that corrects the field, providing an excellent flat field over a 40mm image circle.

Optically Unbeatable

  • Five element in two groups air-spaced objective (FPL-53) in adjustable CNC machined ultra high precision lens cell.
  • Extremely sharp.
  • Excellent color correction.
  • Each lens is Fully Multi-Coated with a special super-high transmission coating (STM Coating) on all surfaces.
  • This f/6.6 telescope is ideal for astrophotography.

2” R&P DDG Focuser

  • The Digital Display Gauge - DDG - allows you to take precise focusing readings down to two decimals precision instantly.
  • Extra-smooth 360 deg. rotatable 2" Rack & Pinion focuser with 1:10 dual speed: a treat to use during astrophotography. No image shifting!
  • Comes with two locking screws on angled positions for heavy load applications.
  • Large aluminum knob with installed thermometer and aluminum protection cover.

Finder / Guidescope Rings Included

  • Includes bracket that can accommodate finders with a tube diameter of up to 60-61mmm. Perfect for adding a finderscope or guiding scope.
  • Viewfinder/Guidescope shown in photos above is illustrative only and NOT included.

Simply Beautiful Finish

  • Pure William Optics quality fit and finish: powder-painted white CNC-machined aluminum tube, dark red trim finish, retractable dewshield, 360 deg. rotatable R&P focuser, dewshield cap, L-shaped Vixen-style mounting base.
  • Top quality anodizing.

Attention to Details

  • Includes 2" & 1.25" adapter.
  • Anti-marring brass compression rings.
  • Carry handle with V-shape night glowing illuminator.
  • 2-year warranty from WO.

Useful Resources

Manufacturer William Optics
Aperture 81 mm
Focal Ratio F/6.6
Focal Length 535 mm
Objective Type Five element with FPL-53 Air Spaced (2 groups), Fully Multi-Coated, STM coatings
Resolving Power 1.43"
Limiting Magnitude 12.2
Lens Shade Retractable
DDG Focuser 2" 360° Rotating Camera-angle Adjuster
1:10 fine focus
Focuser Travel Length 3.15" (80mm)
1.25" Adapter
L-type Mount L Bracket
Field Stops Knife-Edge Baffles
Tube Diameter 90mm
Tube Length 440mm Fully Retracted
484mm Fully Extended
Tube Weight 8.1 lbs. (3.7 kg)

Product Questions & Answers

No questions yet. Be the first to Ask a Question.

You May Also Be Interested In...

William Optics Soft Carry Case for GT81 / GTF81 Telescopes

William Optics Soft Carry Case for GT81 / GTF81 Telescopes

Our Price: $65.00