Brand: William Optics

William Optics ZenithStar 81 Doublet APO (w/ Optional 0.8x Flattener/Reducer) (A-Z81)

Brand: William Optics

William Optics ZenithStar 81 Doublet APO (w/ Optional 0.8x Flattener/Reducer) (A-Z81)

The 81mm ZenithStar APO refractor from William Optics is a great addition to the ranks of telescopes that are devoted to providing fantastic astro-images through high-quality optics and chromatic aberration correction.
  • 2.5" R&P Focuser - The 2.5" R&P focuser is smooth, stable, and reliable. No image shifting!
  • CNC Handle Bar - CNC-made Handle Bar with Vixen type saddle, anodized to match the optical tube.
  • Bahtinov Mask - World's First built-in Clear Bahtinov Mask.
Special Order
$1,198.80 CAD

Accent Color

Red (A-Z81RD) Blue (A-Z81BU) Gold (A-Z81GD)

Flattener Included

P-FLAT6AIII None

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Special Order
$1,198.80 CAD

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Product Description

The William Optics telescope package is fit for incredible and successful imaging sessions! If you have been looking for the ultimate William Optics viewing experience, you have found it!

The 81mm ZenithStar APO refractor from William Optics is a great addition to the ranks of telescopes that are devoted to providing fantastic astro-images through high-quality optics and chromatic aberration correction. Not only does the Z81 telescope have good optics, but it's also easy to use and very portable!

Equipped with FPL-53 glass, this apochromatic refractor provides beautiful colors and clear details. Z81 telescopes have an image circle that works well with Full Frame cameras, when paired with the included 6AIII flattener, by minimizing vignetting and image shifting.

Not only does this package contain all of the bells and whistles normally included with the WO Zenithstar 81 APO Refractor, but it also comes with the option of an Adjustable 0.8x Focal Reducer/Field Flattener (P-FLAT6AIII). Get ready for the imaging package of your dreams!

William Optics Flat6AIII 0.8x Reducer & Field Flattener - M63 to 2"

This William Optics 2" Field Flattener & Reducer has been designed to optimize the flat-field imaging performance of the William Optics Z81 refactor. The APO triplet optics of the Flat6AIII are made with Ohara glass and fully multi-coated to provide good illumination and a beautifully flat field across 97% of full frame sensors. The reducing factor is 0.8X.

Designed with M63 threads on the telescope side, the FLAT6AIII will thread directly into the telescope. Just remove the three screws on the focuser adapter, take off the adapter, and thread the focal reducer/field flattener on in it's stead. The Flat6AIII has 2" threads on the opposite side to accept a 48mm (Wide) T ring for your DSLR. There is even a slot behind the 2" threads to accept an M48 filter.

  • Amount of Adjustment: 5.2 mm
  • Back Focus: 60.2 mm
  • Image Circle: 44 mm

Recommended Optional Accessories

  • T-Mount for
    • M4/3
    • Nikon
    • Canon
    • Sony a
    • Pentax
    • Fuji
  • Guiding Scope
  • Flattener
  • Eye Piece & Prism
  • Finder Scope & Ring
  • Red Dot Finder

What can I see with a William Optics ZenithStar 81 Doublet APO (w/ Optional 0.8x Flattener/Reducer) (A-Z81)?

Here are some simulated views of common objects. Results with your telescope will vary with viewing conditions, obrits, equipment and more.

Jupiter with

25mm Eyepiece - 22x Magnification

(Sold Separately)

Jupiter with

10mm Eyepiece - 56x Magnification

Sold Separately

Jupiter with

5mm Eyepiece - 112x Magnification

Sold Separately

Moon with 25mm Eyepiece

22x Magnification

(Sold Separately)

Moon with 10mm Eyepiece

56x Magnification

Sold Separately

Moon with 5mm Eyepiece

112x Magnification

Sold Separately

Andromeda with 36mm Eyepiece

16x Magnification

Sold Separately

Andromeda with 25mm Eyepiece

22x Magnification

(Sold Separately)

Andromeda with 10mm Eyepiece

56x Magnification

Sold Separately

What's in the Box

  • ZenithStar 81 mm f/6.9 APO Doublet Refractor Telescope OTA
  • 2.5" Rack & Pinion Focuser
  • Mounting Rings
  • Handle Bar
  • Bahtinov Mask Cover
  • Dual Dovetail Plate
  • Carry Case

Specifications

Focal Length: 559mm
Diameter: 81mm
Aperture: f/6.9<
Camera Format: APS-C
Full Frame
Focuser: 2.5" R&P Focuser
Image Circle: > Full Frame
Recommended Flattener: FLAT 6A III
Tube Length: 460mm (Fully Retracted)
560mm (Fully Extended)
Tube Weight: 3.53 kg
Interchangeable T-Mount: Canon EF
Nikon F
Sony E
Pentax
Micro Four Thirds
Fuji FX

Customer Reviews

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F
F.K.C.
An excellent budget telescope for astrophotography

William Optics ZenithStar 81 Doublet with 0.8 reducer performs really well for catching deep space objects. Althrough its focal ratio f/6.9 is not the fastest, its built quality and FPL-53 glass used still allows us to produce very sharp images. Since the exposure time is a bit longer, a good mount is required. It is also a very versatile telescope with focal length 450mm (with reducer) or 560mm (without reducer), which make it suitable for shooting planetary, nebula and deep space objects.

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