The William Optics ZS71 ED refractor uses a doublet with ED glass (low dispersion). Optical instruments of this type are approaching the costly APO triplets for a fraction of the price. The heart of the ZS71 ED is the Japanese doublet Ohara FPL51 ED with high contrast and light f / 5.9. The tube is equipped with a very good 2-inch Rack & Pinion extract with a micrometer 1:10 and the possibility of framing in the range of 360 °. This extractor, due to its high precision, does not depart from the Crayford extracts, in addition we have the possibility of completely blocking and suspending even very heavy accessories. The telescope has a retractable diffuser and mounting foot in the Vixen standard, and the high quality of fitting and finishing has long been the distinguishing feature of William Optics products. WO ZS71 ED is an excellent "away" equipment, especially recommended for astrophotography in wide frames, as well as an observation and digiscoping telescope.
• construction: doublet Ohara FPL51 ED • aperture: 71 mm • light: 1 / 5.9 • focal length: 418 mm • switching capacity: 1.58 " • limiting magnitude: 11 • retractable diffuser: yes • Extractor: 2 "Rack & Pinion, adapter 1.25", microfocus 1:10 • Extraction range: 80 mm (3.2 ") • possibility of cropping the extractor: yes, 360 degree rotation • length: 310 - 455 mm (depending on the position of the separator) • weight: 2.7 kg