William Optics Star 71 Mark II 71mm f/4.9 APO Imaging Refractor 4 Element Apochromat
This scope is ultimately designed for astronomers who want the best results in photographic/CCD imaging. The WO-Star71 Mark II imaging telescope provides pinpoint stars at the very edge of a 45mm imaging circle
Version 2 has one less element, however now there are 2 elements that utilize FPL-53 ED glass to achieve the same optical performance, while making it easier to collimate during assembly.
Due to the continuous fluctuations of the pound exchange rate, we'd advise you to contact us before you order to check out the current price for this telescope.
This telescope is available on back order only!
- 71mm f/4.9 Imaging Refractor Telescope.
- FPL-53 glass for color free apochromatic performance.
- Covers 45mm full frame imaging circle.
- 2.5" dual speed R&P focuser.
- Includes mounting rings and Vixen style dovetail.
- Weight = 4.5 lbs / 2.05 kg (OTA only); 5.3 lbs / 2.4 kg (OTA with rings and dovetail).
- Focuser drawtube travel = 1.38" / 35mm.
Focuser drawtube terminates in a male M48 thread. Telescope comes with a wide M48-Canon EOS adapter ring. Similar rings are available from other supplier for other brands of cameras. Not a conventional 2" focuser tube with locking thumbscrews..
Optional 1.25" 90-deg dielectric mirror diagonal sold separately for those wishing to use this as a visual. This diagonal comes with a custom adapter that connects directly to the M65(First Version)/ M63(Second Version) female thread on the telescope's focuser tube; you cannot use standard 1.25" diagonals. Telescope cannot reach focus with larger 2" diagonals.
Optional soft carry case available separately.
|Focal Length||350.2 mm|
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)|
|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 Apochromatic Lenses
All WO refractors objective are double tested and inspected before shipping to our customer, these telescopes are free of coma and astigmatism.
Since all individual lens surfaces are machine coated sometime it could have visual imperfections which do not affect the objective 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|