William Optics Gran Turismo GT 71 II in white and gold, with a dedicated FLAT 6A III field flatness corrector (WO P-FLAT6AIII).
William Optics Gran Turismo GT 71 II is the latest version of the compact apochromat, which, considering the color correction and sharpness of the image, leaves other products in its class far behind.
The heart of this telescope is the three-element APO-ED optical system. One of the most perfect optical materials - synthetic fluorite - was used for the production of the low-dispersion lens. This material, produced by the renowned Japanese company Ohara, under the designation FPL-53, is characterized not only by a high value of the Abbe number, but also much more chemically stable than natural crystalline fluorite. The use of carefully selected types of glass and coating the lenses with an SMC coating means that the image obtained with the William Optics Gran Turismo GT 71 II telescope is unmatched in terms of sharpness, detail and contrast.
The set with the optical tube includes a professional focal length reducer and FLAT 6A III flattener. It is a triplet made of carefully selected optical glasses by Ohara, which allows for cooperation with both full-frame matrices and the APS-C and M4 / 3 formats.
The tube of the telescope is mounted on precisely made clamps, equipped with a Vixen socket for the mounting of a finder or guider, as well as a Vixen / Arca-Swiss foot.
• apochromatic triplet with an air gap and a low-dispersion element made of Japanese FPL-53 glass (synthetic fluorite)
• three-element focal length reducer / flattener with a multiplicity of 0.8x with the possibility of mounting filters mounted in a holder with an M48 thread
• solid rack & pinion extractor equipped with coarse and fine focus adjustment knobs
• optical tube clamps made in CNC technology
• mounting foot compatible with Vixen and Arca-Swiss sockets, allowing the tube to be mounted on a mount or photographic tripod
• optical system of the telescope: APO-ED triplet with an air gap
• flattener / focal reducer: FLAT 6A III
• flattener / focal reducer optics: triplet with full multilayer coating (FMC)
• multiplicity of the flattener / focal reducer: 0.8x
• Objective diameter: 71 mm
• focal length (without FLAT 6A III): 419 mm
• focal length (with FLAT 6A III): 335 mm
• lighted up (without FLAT 6A III): f / 5.9
• lighted up (from FLAT 6A III): f / 4.7
• ED lens material: FPL-53 glass (Ohara, Japan)
• optical system coating: SMC coating
• Compatible sensor sizes: APS-C, full frame
• compatible photographic systems (via interchangeable T-rings): Canon EF, Nikon F, Sony E, Pentax, Micro 4/3, Fuji FX
• back focus (for FLAT 6A III): 64.1 mm
• correction (for FLAT 6A III): 9.1 mm
• fokuser: 2.5 "
• type of eyepiece extractor: rack & pinion, dual speed
• thread for connecting the flattener / focal reducer: M63
• finder foot: Vixen
• mounting for mounting: Vixen / Arca-Swiss
• tube length (folded): 392 mm
• tube length (extended): 470 mm
• tube weight: 2.95 kg
• tube finish: white - gold
• William Optics Gran Turismo GT 71 II refractor
• FLAT 6A III flattener / focal reducer
• the pupa
• Bahtinov's mask with its mount
• a lens cap
• fixing clamps with the Vixen / Arca-Swiss foot
• transport cover