William Optics WO-Star 71 - 71mm f/4.9 Apo Imaging Refractor - A-WO71

William Optics   ——   SKU: WIL-A-WO71
$1,372.70 CAD
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Product Info

William Optics WO-Star 71 - 71mm f/4.9 APO Imaging Refractor

  • This William Optics WO-Star 71 is a 71mm f/4.9 APO Refractor Telescope designed especially for astro-imaging
  • FPL-53 glass for color free apochromatic performance
  • 5 elements in 3 groups in a 3-1-1- configuration; New, unique, patented design - not a conventional objective/flattener/reducer design
  • Covers a 45mm full frame imaging circle
  • 2.5" dual speed Rack & Pinnion focuser
  •  Includes mounting rings and Vixen style dovetail
  • Weight = 4.5 lb / 2.05 kg (OTA only); 5.3 lb / 2.4 kg (for OTA with rings and dovetail)
  • Focuser drawtube travel = 1.38" / 35mm

This telescope is designed for astronomers who want the ultimate results in photographic/CCD imaging. The WO-Star71 APO imaging refractor telescope provides pinpoint stars out to the very edge of a 45mm imaging circle.

The focuser drawtube of this WO-Star 71 71mm f/4.9 Apo Imaging Refractor telescope terminates in a male M48 thread. Telescope comes with a wide M48-Canon EOS adapter ring. Similar rings are available from other suppliers for other brands of cameras. Not a conventional 2" focuser tube with locking thumbscrews.

This 71mm f/4.9 APO Imaging Refractor Telescope from William Optics will accept an optional 1.25" 90-deg dielectric mirror diagonal sold separately for those wishing to use this as a visual scope. This diagonal comes with a custom adapter that connects directly to the  M65 (M63) female thread on the telescope's focuser tube; you cannot use standard 1.25" diagonals. This telescope cannot reach focus with larger 2" diagonals. A high quality soft carry bag is available as an option.

Telescope Specifications:

Focal Ratio
Focal Length
350.2 mm
Objective Type 
New improved (Star 71-II)
4 elements in 3 groups (2-1-1- configuration; new, unique, patented design)
Objective Type(Star 71) 
5 elements in 3 groups (3-1-1- configuration; new, unique, patented design)
Lens Shade
R&P Focuser
2.5" dual speed R&P focuser 
Focuser drawtube travel = 1.38" / 35mm
Type of Mount
Includes mounting rings and Vixen style dovetail
Tube Weight
Weight = 4.5 lbs / 2.05 kg (OTA only); 5.3 lbs / 2.4 kg (OTA with rings and dovetail)

Specification for ED Lenses:

All WO refractor objectives are double tested and inspected before shipping to our customers. These telescopes are free from coma and astigmatism. Since all individual lens surfaces are machine coated, there may be some visual imperfections which do not affect the objective's optical performance.

Dimensions of scratches and points shall not exceed the following values:

Scratches Width, not more, mm 0.025mm
Total length, not more 1/4 of total lens diameter. 
Quantity no more 3
Dots or spot points No more, mm 0.4mm
Quantity, no more 3
Accumulation of defects Limited area, mm 0.8mm^2
Total area of scratches and points, no more, square mm 5.8mm^2