The William Optics Gran Turismo 81 refractor is a three-element apochromatic refractor using the FPL-53 glass, with a diameter of φ = 81 mm and light intensity f / 5.9.
The tube is equipped with a great 2.5-inch Rack and Pinion extractor with a 10: 1 microfocuser, smoothly working, stable - you can rely on it.
The telescope has a retractable urinal and a mounting foot in the Vixen standard, and the high quality of fit and finish has been a hallmark of William Optics products for a long time.
So we have beautiful astrophotographic equipment - for connoisseurs.
Description and a lot of interesting materials - see the manufacturer's website: https://williamoptics.com/gran-turismo-81-iv
• construction: Apo FPL53 triplet
• aperture: 81 mm
• lighted: f / 5.9
• focal length: 478 mm
• retractable diffuser: included
• dovetail rail: included
• carrying handle: on clamps, included
• Bahtinov's mask: included
• Camera position rotator: yes, included
• Extract: 2.5 "Rack and Pinion, 10: 1 microfokuser
• recommended flattener: FLAT 6A III
• application: APS-C, Full Frame
• length: 390 - 460 mm (depending on the position of the urinal)
• weight: 3.9 kg
• Object : M31, a galaxy in Andromeda
• Setup : Sky-Watcher EQ6-R, guided ASI120 Mini, William Optics Gran Turismo 81 IV with 6A III flattener, ZWO ASI 2400 MC chilled camera;
• Execution : RGB from Bortle 2 (see: Bortle Scale in Wiki), 27 x 240 s, September 2020
(click to enlarge)