{"title":"William Optics Gran Turismo GT Refractors","description":"\u003cp\u003eWilliam Optics Gran Turismo (GT) refractors are compact apochromatic triplets for portable imaging and visual observing. The collection includes the Gran Turismo 71 APO triplet, a light travel scope, and the Gran Turismo 81 in its standard form and as the Gran Turismo WIFD 81 with internal focusing.\u003c\/p\u003e\u003cp\u003eWith a matching flattener, these small refractors suit wide nebula and galaxy fields, and they ride easily on a compact equatorial or harmonic mount.\u003c\/p\u003e","products":[{"product_id":"william-optics-gran-turismo-71-apo-triplet","title":"William Optics Gran Turismo 71 APO Triplet","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e71mm Triplet Apochromatic Lens\u003c\/li\u003e\n\u003cli\u003e419mm Focal Length at f\/5.9\u003c\/li\u003e\n\u003cli\u003e44mm Full-Frame Image Circle\u003c\/li\u003e\n\u003cli\u003e2.5\" Rack \u0026amp; Pinion Focuser\u003c\/li\u003e\n\u003cli\u003eOTA Weight: 2.95 kg (6.5 lbs)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eWilliam Optics Gran Turismo 71 APO Triplet\u003c\/h2\u003e\n\u003cp\u003eThe William Optics Gran Turismo 71 APO Triplet combines a 71mm aperture with a 419mm focal length in a fast f\/5.9 optical design. Its triplet objective lens, featuring FPL-53 glass, delivers sharp, high-contrast images free of false color, illuminating a full-frame 44mm image circle. Weighing just 2.95 kg, the GT71 is engineered for premium wide-field astrophotography on portable, lightweight tracking mounts.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eTriplet APO Optics: 419mm at f\/5.9 with FPL-53 Glass\u003c\/h3\u003e\n\u003cp\u003eThe core of the GT71 is its air-spaced triplet apochromatic lens. This design uses an FPL-53 glass element to virtually eliminate chromatic aberration, ensuring star colors are rendered accurately and details are resolved with high contrast. The native 419mm focal length at f\/5.9 provides a versatile field of view, ideal for capturing large nebulae and star clusters while maintaining a manageable image scale for galaxies.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eImaging-Ready Mechanics: 2.5\" R\u0026amp;P Focuser and 44mm Image Circle\u003c\/h3\u003e\n\u003cp\u003eBuilt for modern astrophotography, the Gran Turismo 71 is equipped with a heavy-duty 2.5\" rack-and-pinion focuser. This focuser provides 93mm of travel and can handle heavy imaging trains without slipping, while being directly compatible with electronic focusers like the ZWO EAF. The optical system is designed to produce a flat, well-illuminated 44mm image circle, fully covering full-frame sensors from edge to edge with the addition of an optional flattener.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eCamera Compatibility:\u003c\/strong\u003e The 44mm image circle supports Full Frame, APS-C, and M4\/3 sensors, offering flexibility for your current and future cameras.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOptional Reducers:\u003c\/strong\u003e Choose the FLAT GT 1.0x for edge-to-edge correction at the native 419mm focal length, or the FLAT 6AIII 0.8x reducer to transform the scope into a faster f\/4.7 system for even wider fields.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCamera Angle Adjuster:\u003c\/strong\u003e A 360° camera angle adjuster is included, allowing for precise framing of your target without altering focus.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eGrab-and-Go Design: 2.95 kg with Vixen\/Arca-Swiss Dovetail\u003c\/h3\u003e\n\u003cp\u003eThe entire optical tube assembly weighs only 2.95 kg (6.5 lbs), making the GT71 an ideal choice for portable setups like the Sky-Watcher Star Adventurer or iOptron SkyGuider Pro. Its adjustable tube length, from 392mm to 470mm, allows for compact storage and travel. The integrated dovetail bar features both a Vixen-style rail for astronomy mounts and an Arca-Swiss profile for direct attachment to standard photographic tripods, adding to its field versatility.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan the William Optics GT71 be used with a full-frame camera?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The Gran Turismo 71 is designed with a \u003cstrong\u003e44mm image circle\u003c\/strong\u003e, which is large enough to fully illuminate a standard full-frame sensor (typically 43mm diagonal) without vignetting. For optimal edge-of-field star shapes, pairing it with a dedicated flattener like the FLAT GT 1.0x or the FLAT 6AIII 0.8x reducer is required.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat kind of mount do I need for the Gran Turismo 71?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWith an OTA weight of only \u003cstrong\u003e2.95 kg (6.5 lbs)\u003c\/strong\u003e, the GT71 is exceptionally versatile. It performs well on robust star trackers like the Sky-Watcher Star Adventurer GTi or small equatorial mounts in the EQ3\/EQM-35 class. For more serious imaging with autoguiding, a mount from the HEQ5\/CEM26 class is recommended.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow will the GT71 perform on the North American Nebula (NGC 7000) with the 0.8x reducer?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe GT71 is an excellent choice for this target. With the optional \u003cstrong\u003eFLAT 6AIII 0.8x reducer\u003c\/strong\u003e, the focal length becomes approximately 335mm at f\/4.7. Paired with an APS-C sensor, this combination can easily frame the entire North American Nebula and the adjacent Pelican Nebula (IC 5070) in a single shot with high resolution.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the GT71 suitable for visual astronomy on objects like the Orion Nebula (M42)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eAbsolutely. While optimized for imaging, the GT71's triplet APO lens provides superb, high-contrast views for visual use. On the Orion Nebula (M42), you can expect sharp, pinpoint stars across the Trapezium cluster and clear views of the surrounding nebulosity. With a low-power, wide-field eyepiece, the \u003cstrong\u003e419mm focal length\u003c\/strong\u003e will frame the entire nebula beautifully.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the benefit of the GT71's f\/5.9 focal ratio?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eAn \u003cstrong\u003ef\/5.9 focal ratio\u003c\/strong\u003e is considered \"fast\" in astronomical terms. This allows the telescope to collect a significant amount of light in a shorter period compared to slower f\/8 or f\/10 systems. For imagers, this means you can capture more signal and detail in your sub-exposures, reducing total integration time.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat adapters are included with the William Optics Gran Turismo 71?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe GT71 includes two visual adapters. The first is an \u003cstrong\u003eM63 to 2\" adapter\u003c\/strong\u003e, allowing you to attach standard 2\" diagonals and eyepieces. The second is a \u003cstrong\u003e2\" to 1.25\" adapter\u003c\/strong\u003e, which steps down the connection to accommodate 1.25\" accessories.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eLens Type\u003c\/td\u003e\n\u003ctd\u003eTriplet APO Prime Lens\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDiameter\u003c\/td\u003e\n\u003ctd\u003e71 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Length\u003c\/td\u003e\n\u003ctd\u003e419 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Ratio\u003c\/td\u003e\n\u003ctd\u003ef\/5.9\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eImage Circle\u003c\/td\u003e\n\u003ctd\u003e44 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocuser\u003c\/td\u003e\n\u003ctd\u003e2.5\" R\u0026amp;P Focuser Compatible with EAF\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocuser Travel\u003c\/td\u003e\n\u003ctd\u003e93 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCamera Format Support\u003c\/td\u003e\n\u003ctd\u003eFull Frame, APS-C, M4\/3\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOptional Flattener\/Reducer\u003c\/td\u003e\n\u003ctd\u003eFLAT GT 1.0x, FLAT 6AIII 0.8x\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDovetail Type\u003c\/td\u003e\n\u003ctd\u003eVixen \u0026amp; Arca-Swiss Compatible\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTube Length\u003c\/td\u003e\n\u003ctd\u003e392 mm (retracted) - 470 mm (extended)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOTA Weight\u003c\/td\u003e\n\u003ctd\u003e2.95 kg \/ 6.5 lbs\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eGran Turismo 71 APO OTA\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eM63 to 2\" Visual Back Adapter\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003e2\" to 1.25\" Visual Back Adapter\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003e360° Camera Angle Adjuster (CAA63)\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eMounting Rings \u0026amp; Dovetail Bar\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eLens Cap\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/william-optics-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eWilliam Optics 2-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"William Optics","offers":[{"title":"Red","offer_id":44967229260061,"sku":"WO-A-F71GTII-RD","price":1515.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/William-Optics-GT71-1.jpg?v=1722276408"},{"product_id":"william-optics-gran-turismo-wifd-81","title":"William Optics Gran Turismo WIFD 81","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e81mm Aperture Triplet Apochromatic Refractor\u003c\/li\u003e\n\u003cli\u003eFPL-53 Ohara Glass for Superior Color Correction\u003c\/li\u003e\n\u003cli\u003eWilliam Optics Internal Focusing Design (WIFD)\u003c\/li\u003e\n\u003cli\u003eIncluded Dual-Side Vixen\/Arca-Swiss Mounting Plate\u003c\/li\u003e\n\u003cli\u003eIntegrated Bahtinov Mask Focusing Aid\u003c\/li\u003e\n\u003cli\u003ePadded Soft Carry Case for Transport and Storage\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eWilliam Optics Gran Turismo WIFD 81 Apochromatic Refractor\u003c\/h2\u003e\n\u003cp\u003eThe William Optics Gran Turismo WIFD 81 combines an 81mm triplet objective with a robust M92 threaded connection for a stable, zero-flexure imaging train. The included M92 to M63 adapter ensures compatibility with a wide range of correctors and cameras, making this apochromat a versatile core for any astrophotography setup.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003e81mm FPL-53 Triplet: Apochromatic Optics for Pure Color\u003c\/h3\u003e\n\u003cp\u003eAt the heart of the Gran Turismo 81 is an air-spaced triplet objective featuring premium FPL-53 glass from Ohara, Japan. This design achieves apochromatic correction, virtually eliminating chromatic aberration for true-to-life color and razor-sharp stars. You see no distracting purple fringing on bright stars like Vega or Sirius, only clean, high-contrast detail whether you're observing visually or imaging deep-sky objects.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eWIFD Focuser \u0026amp; M92 Adapter: A Zero-Flexure Imaging Platform\u003c\/h3\u003e\n\u003cp\u003eThe proprietary William Optics Internal Focusing Design (WIFD) provides an exceptionally smooth and stable focusing mechanism critical for astrophotography. Unlike traditional focusers that move a drawtube, the WIFD moves the lens assembly internally, meaning your camera and imaging train remain fixed. This design eliminates sag and tilt, preserving perfect alignment even with heavy equipment attached to the M92 threaded rear port.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eIncluded Hardware:\u003c\/strong\u003e The telescope arrives ready for the field with mounting rings, a sturdy handle bar, and a versatile dual-side plate compatible with both Vixen and Arca-Swiss style saddles.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFocusing Perfected:\u003c\/strong\u003e A Bahtinov mask is cleverly integrated into the lens cap, providing a simple and precise way to achieve critical focus every time.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eImaging Train Note:\u003c\/strong\u003e For serious astrophotography, a dedicated field flattener is required to achieve a perfectly flat field across the entire sensor. This is an optional accessory and is not included with the optical tube.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat makes the William Optics Gran Turismo WIFD 81 ideal for astrophotography?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003eGran Turismo WIFD 81\u003c\/strong\u003e is built for imaging. Its core strengths are the FPL-53 triplet lens for color-free images and the WIFD internal focuser. The WIFD prevents focuser sag and tilt, which is a common issue with external focusers when using heavy cameras and filter wheels.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow would the GT81 WIFD perform on a target like the Andromeda Galaxy (M31)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003eGT81 WIFD\u003c\/strong\u003e is an excellent wide-field instrument for large targets like the Andromeda Galaxy (M31) or the North American Nebula (NGC 7000). With a compatible field flattener, you can capture these expansive objects in a single frame with sharp stars from edge to edge.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eI have a mount with a Vixen-style saddle. Do I need to buy a new dovetail for the GT81 WIFD?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, you do not. The \u003cstrong\u003eGT81 WIFD\u003c\/strong\u003e includes a dual-side mounting plate that is compatible with both standard Vixen-style saddles and Arca-Swiss saddles, offering broad compatibility with most astronomical mounts right out of the box.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the benefit of the FPL-53 glass in the Gran Turismo 81's triplet lens?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003e\u003cstrong\u003eFPL-53\u003c\/strong\u003e is a high-grade, extra-low dispersion (ED) glass that provides superior correction of chromatic aberration, or \"color fringing.\" This means light of all colors comes to the same sharp focus, resulting in higher contrast, truer star colors, and finer visible detail compared to standard doublet or ED glass designs.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDoes the William Optics GT81 WIFD come with a field flattener?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, a field flattener is a required but \u003cstrong\u003eoptional accessory\u003c\/strong\u003e for astrophotography. While the telescope provides a sharp central image, a flattener is necessary to correct the natural field curvature of the optics and ensure pinpoint stars across the entire sensor of a DSLR or dedicated astronomy camera.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is \"WIFD\" and why is it better than a traditional focuser?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003e\u003cstrong\u003eWIFD\u003c\/strong\u003e stands for William Optics Internal Focusing Design. Instead of an external drawtube that extends and retracts, the WIFD moves the objective lens internally. This creates a sealed, rigid system with zero image shift or tilt, providing a more stable and reliable platform for focusing, especially with the weight of an imaging setup.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eAperture\u003c\/td\u003e\n\u003ctd\u003e81mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOptical Design\u003c\/td\u003e\n\u003ctd\u003eApochromatic Triplet\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eGlass Type\u003c\/td\u003e\n\u003ctd\u003eFPL-53 Ohara Glass\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocuser Design\u003c\/td\u003e\n\u003ctd\u003eWIFD (William Optics Internal Focusing Design)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAvailable Colors\u003c\/td\u003e\n\u003ctd\u003eRed, Gold, Grey\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eGran Turismo 81 Main Tube\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eBahtinov Mask Lens Cap\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eM92 to M63 Adapter\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDual-Side Vixen\/Arca-Swiss Plate\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eMounting Rings \u0026amp; Handle Bar\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eSoft Carry Case\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eAllen Key Set\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/william-optics-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eWilliam Optics 2-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"William Optics","offers":[{"title":"Red","offer_id":44968075034909,"sku":"WO-T-GT-81RD-WIFD","price":3033.0,"currency_code":"CAD","in_stock":true},{"title":"Gold","offer_id":48966030000413,"sku":"WO-T-GT-81GD-WIFD","price":3033.0,"currency_code":"CAD","in_stock":true},{"title":"Grey","offer_id":48966030033181,"sku":"WO-T-GT-81SG-WIFD","price":3033.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/William-Optics-GT81-WIFD-1.jpg?v=1722276662"}],"url":"https:\/\/davidastro.com\/collections\/william-optics-gran-turismo-gt-refractors.oembed","provider":"David Astro","version":"1.0","type":"link"}