William Optics ZenithStar 81mm f/6.9 Doublet Apo Refractor with Soft Case - Gold # Z81GD

All New 2019 Super ZenithStar 81 F6.9 imaging APO - Innovative Bahtinov Mask Cover (Patented) and soft carry case included!

ZenithStar 81 Doublet Apochromatic Refractor 

The William Optics ZenithStar 81 is an extremely well crafted and versatile refractor, an ideal instrument for deep sky imaging with DSLRs or dedicated astronomy cameras with APS-C and full-frame sensors. It’s also a great tool for visual observation of a wide range of celestial objects from the moon and planets to nebulae and star clusters and brighter galaxies, as well as for solar observation with a safe solar filter.

The ZS81 features an 81mm f/6.9 FPL 53 air-spaced doublet apochromatic objective lens in a CNC machined ultra-high precision cell. These premium optics provide razor-sharp images and excellent color rendition. When paired with a 0.8x William Optics field flattener and focal reducer (sold separately), the scope works at a fast f/5.5 with a flat field across the entire 43.3mm diagonal of a full-frame sensor.

Premium Build Quality and Compact Form Factor

Like all telescopes from William Optics, the ZenithStar 81 incorporates rock-solid mechanics and built quality. The scope includes high-quality mounting rings to safely and securely hold the telescope to the mount. The rings are anodized to match the color of the handle, dovetail, and focuser, giving the scope an attractive, premium appearance. 

With a focal length of 559mm, this f/6.9 telescope has a retracted length of just 456mm (18”), compact enough to qualify as carry-on luggage with many airlines. The tube weighs just 3.50kg (7.8 lbs) including tube rings and dovetail plate.

Heavy-Duty Focuser, Rings, Soft Case and Accessories

The William Optics ZS 81 features a patented objective lens cover that doubles as clear Bahtinov focusing mask. This makes it a snap to achieve sharp focus when setting up for astrophotography.

The ZS 81 also features a heavy duty 10:1 dual-speed 2.5” rack and pinion focuser with tension screws to securely hold a bigger camera and accessories without slipping or image shift, even during longer exposures. The focuser also includes two additional screws to mount an optional red-dot finder. 

A convenient CNC-machined carrying handle mounts on top of the rings and doubles as a holder for a guide scope (sold separately). On the bottom of the rings is a 210mm long reversible dovetail with a Vixen rail on one side and an Arca Swiss mount on the other for mounting the scope to a camera tripod for grab-and-go terrestrial and astronomical observation.

A soft carry case is now also included with this telescope.

Specifications:

• Focal length: 559mm
• Diameter: 81mm
• Aperture: f/6.9
• Camera Format: APS-C, Full Frame
• Focuser: 2.5" R&P
• Image Circle: Full Frame
• Recommended Flattener: Flat6AIII
• Tube Length (Fully Retracted): 460mm
• Tube Length (Fully Extended): 560mm
• Tube Weight: 3.53kg
• Interchangeable T-Mounts (sold separately): Canon EF, Nikon F, Sony E, Pentax, Micro Four Thirds, Fuji FX

All William Optics telescopes come with a 2-year no-fuss warranty from William Optics.