William Optic GTF81 5 elements APO

Rp0

New

William Optic GTF81 5 elements APO Include : GTF 81 OTA (Optical Tube Assembly)
Pesan Disini
Add to wishlist
Categories: ,

Description

The stunning new William Optics GTF 81APO is the new jewel of the apochromatic refractor world.
From the pristine white finish on the CNC to the elegant red beauty which has more than just good looks.

New GTF 81 features total 5-element in 2 groups design by using high-quality FPL-53 extra-low dispersion glass that reduces any secondary spectrum to an unbelievable degree,the second group of ED element (flat field corrector) is correcting the edge of flatness to the best quality (cover up to 40mm of 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/5.9 lens is ideal for astrophotography.

2.5” R&P  Focuser

  • Extra-smooth 360 deg. rotatable 2.5″ 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.

Attention to Details

  • 2″ & 1.25″ adapter included in the price.
  • Anti-marring brass compression rings.
  • Carry handle with V-shape night glowing illuminator.
  • Guiding scope are optional.
  • 90mm mounting rings are optional.
  • Though you will never need it, you have a 2-year warranty from WO, and the certainty that we will be there to assist you even beyond that, if you need!


Specification

 

Aperture 81 mm
Focal Ratio F/5.9
Focal Length 478 mm
Objective Type Five element with FPL-53 Air Spaced (2 groups), Fully Multi-Coated, STM coatings
Resolving Power 1.43 seconds of arc
Limiting Magnitude 12.2
Lens Shade Retractable
Focuser 2? 360° Rotating Camera-angle Adjuster, 1:10 fine focus
Focuser Travel Length 3.15? (80mm)
1.25? Adapter
1.25? Adapter Brass Compression Rings
Field Stops 2 Baffles
Tube Diameter 90mm
Tube Length 440mm Fully Retracted
484mm Fully Extended
Tube Weight 3.7 kg

Reviews

There are no reviews yet.

Be the first to review “William Optic GTF81 5 elements APO”

Your email address will not be published. Required fields are marked *