William Optics AP 73/430 Super ZenithStar 73 Red OTA Apochromatic refractor telescope

William Optics ZenithStar 73 mm f/5.9 Apochromatic - Red

The ZenithStar series from William Optics consists of compact, but very high quality apochromats that are ideal for use with a DSLR camera. With them, very good wide-angle images of large star fields can be achieved. In combination with the optional flattener, a corrected field of view of 45 millimeters in diameter is obtained.

The lightweight and compact ZenithStar Apo and a DSLR fit perfectly on a photo mount, such as the Star Adventurer from Skywatcher or the SkyGuider Pro from iOptron: a lightweight and uncomplicated system for astrophotography.

Features:

This 73mm ZenithStar Doublet APO Refractor 73mm model from William Optics features Ohara FPL53 glass from Japan and a saddle handle bar that accepts Synta-style dovetails, such as the UniGuide guidescope or sliding base guide rings (not included). The ZenithStar 73 also comes with a 2.5" Rack & Pinion focuser and a double-sided dovetail bar. The William Optics DSD 210 plate is sized Vixen and Arca Swiss on each end of the plate. The plate has two 1/4-20 tapped holes.

Ohara FPL53 vs FPL51 ED glass
The dispersion properties of ED and SD glass elements are important in determining the overall color correction. The Abbe index is used to quantify the dispersion of a particular glass. Pure fluorite offers the lowest dispersion at around 94.99 V, Ohara's FPL53 glass is very close to fluorite at 94.93 V and is often referred to as synthetic fluorite. FPL53 is also noticeably better than Ohara's lower specification FPL51 glass, which offers an abbe index of 81.54 V.

Summary general characteristics:

The Zenithstar 73 is a two-element APO refractor. Using FPL53 glass, this telescope provides excellent aberration correction.

♦ The two-element lens with FPL53 cools faster than the triplet

♦ 73 mm aperture, 430 mm focal length

♦ 2.5" R&P focuser with no image shift

♦ Bahtinov mask for easy focusing

♦ CNC handle bar for easy handling

Technical specifications:

• Optics Refractor Type
• Aperture (mm) 73
• Focal length (mm) 430
• Aperture ratio (f/) 5.9
• Light gathering capacity 110
• Maximum useful magnification 146
• Tube material Aluminum
• Transport length (mm) 310
• Tube weight (kg) 2.5
• Limit value (mag) 11.1
• Resolution capability 1.58
• Tube construction Full tube
• Lens design Doublet
• Construction type Apochromatic

Focuser

• Aperture (mm) 64
• Type of construction Rack and pinion
• Gear reduction 1:10 Fine movement

Mount

• Mounting type no mounting
• GoTo control no
• Type of construction OTA

Included accessories

• Carrying bag yes
• Prism rail Vixen-Style
• Tube clamps yes
• Spray shield yes
• Focusing aid Bahtinov mask
• Searcher schuh Prism clamp
• Carrying handle yes

General

• ZenithStar series
• Color red

Recommended for

• Beginners no
• Advanced yes
• Observatories no