The William Optics ZenithStar 73 is an extremely well crafted and compact refractor, an ideal instrument for wide-field 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 terrestrial observation.

The William Optics Zenithstar 73 f/5.9 apochromatic refractor features an air-spaced multicoated doublet objective lens and the premium mechanics and finish that’s typical of William Optics scopes. The objective features Ohara FPL-53 ED glass for superb control of false color and sharp, high-contrast images. When paired with a William Optics field flattener (sold separately), the scope features a flat field across the entire 43.3mm diagonal of a full-frame sensor.

With a focal ratio of f/5.9 and focal length of 430mm, the WO Zenithstar 73 is the perfect instrument for imaging extended objects such as the California Nebula, the Rosette Nebula, the Veil Nebula, the Sword and Belt of Orion, and the Andromeda Galaxy. Yet the scope is compact enough to work with nearly any medium-duty equatorial mount. It weighs just 2.9kg (6.4lbs) and measures 315mm with the dew shield retracted, portable enough for travel and small enough for carry-on luggage with most airlines.

Heavy-Duty Focuser, Rings, Soft Case and Accessories

The William Optics ZS73 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 ZS73 also features a heavy duty 10:1 dual-speed 2.5” rack and pinion focuser with tension screws to securely hold camera and accessories without slipping or image shift, even during longer exposures. One focuser knob even includes an integrated thermometer to help you track small temperature changes that might affect focus during your imaging sessions.

A convenient CNC-machined carrying handle mounts on top of the dual mounting rings. A dovetail in the handle accommodates an additional set of rings for a guide scope (guide scope rings and guide scope sold separately). On the bottom of the mounting rings is a 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: 430mm
• Diameter: 73mm
• Aperture: f/5.9
• Camera Format: APS-C, Full Frame
• Focuser: 2.5" R&P
• Image Circle: > Full Frame
• Recommended Flatteners: Flat73A, Flat73R
• Tube Length (Fully Retracted): 315 mm
• Tube Length: (Fully Extended): 415 mm
• Dew shield OD: 91mm / 3.58"
• Tube Weight: 6.4 lb (2.9 kg)
• Interchangeable T-Mount (sold separately): Canon EF, Nikon F, Sony E, Pentax, Micro Four Thirds, Fuji FX

All William Optics telescopes come with a 2-year manufacturer warranty