{"title":"William Optics UltraCat Astrographs","description":"\u003cp\u003eWilliam Optics UltraCat astrographs are Petzval refractors in the Cat series, built for fast, flat-field deep-sky imaging without a separate flattener. The UltraCat 56, 76 and 108 work at f\/4.8 and use WIFD internal focusing.\u003c\/p\u003e\u003cp\u003eThe Ultra-Cat 131 at f\/4.9 is the largest in the line, for more resolution on smaller galaxies and nebulae. The small apertures suit travel rigs, while the bigger ones need a sturdier equatorial or harmonic mount.\u003c\/p\u003e","products":[{"product_id":"william-optics-ultracat-108-f-4-8-wifd","title":"William Optics UltraCat 108 f\/4.8 WIFD","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e108mm Aperture, 5-Element Advanced Petzval Optical Design\u003c\/li\u003e\n\u003cli\u003eFast f\/4.8 Focal Ratio with 518mm Focal Length\u003c\/li\u003e\n\u003cli\u003eMassive 60mm Flat-Field Image Circle\u003c\/li\u003e\n\u003cli\u003ePatented William Optics Internal Focuser Design (WIFD)\u003c\/li\u003e\n\u003cli\u003eSupports Medium Format, Full Frame, and APS-C Sensors\u003c\/li\u003e\n\u003cli\u003e7.96 kg Optical Tube Assembly Weight\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 UltraCat 108 f\/4.8 WIFD\u003c\/h2\u003e\n\u003cp\u003eThe William Optics UltraCat 108 f\/4.8 WIFD integrates a 108mm, 5-element Petzval optical system to deliver a massive 60mm flat image circle at a fast f\/4.8 focal ratio. With a 518mm focal length and an OTA weight of just 7.96 kg, this astrograph is engineered for demanding imagers using full-frame and medium format cameras. The innovative internal focuser provides 30mm of precise travel, ensuring perfect focus without altering the telescope's 512.9mm minimum tube length or balance.\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\u003e5-Element Petzval Optics: A Flat 60mm Image Circle at f\/4.8\u003c\/h3\u003e\n\u003cp\u003eThe UltraCat 108's optical core is an advanced 5-element Petzval design that requires no additional field flattener. This integrated system uses a combination of two Super ED, one ED, one Lanthanum, and one X-Element glass to produce a perfectly flat 60mm image circle, ensuring pinpoint stars from the center to the corners of even medium-format sensors. At f\/4.8, you can capture deep signal on faint nebulae and galaxies with shorter exposure times.\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\u003ePatented WIFD Focuser: 30mm of Stable, Internal Travel\u003c\/h3\u003e\n\u003cp\u003eWilliam Optics' patented Internal Focuser Design (WIFD) eliminates the primary weakness of traditional refractors: focuser sag and balance shift. By moving the optical elements internally over a 30mm travel distance, the camera and imaging train remain fixed. This rock-solid connection prevents tilt and flexure, maintaining perfect orthogonality to the image plane, which is critical for achieving sharpness across the large 60mm field. The focuser is also compatible with electronic focusers like the ZWO EAF for automated imaging routines.\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\u003e7.96 kg OTA with Integrated Rotator and Tilt Adjuster\u003c\/h3\u003e\n\u003cp\u003eWeighing only 7.96 kg, the UltraCat 108 OTA is remarkably portable for its aperture and capabilities, making it compatible with a wide range of mid-to-heavy-payload equatorial mounts. The system includes professional-grade tools for perfect camera alignment right out of the box. An integrated camera rotator allows for effortless framing of your target, while the included Sensor Tilt Xterminator gives you fine control to eliminate any residual tilt in your imaging train.\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\u003eM48, M54, and M68 Adapters for Medium Format to M4\/3 Sensors\u003c\/h3\u003e\n\u003cp\u003eThe UltraCat 108 is designed for immediate integration into your existing setup. It ships with a comprehensive set of M48, M54, and M68 camera adapters, accommodating everything from standard 2\" filter wheels to large-format cameras. This ensures a wide, unvignetted light path to capitalize on the full 60mm image circle. The system also supports a wide range of T-mounts for Canon, Nikon, Sony, Pentax, MFT, and Fuji cameras, offering versatility for both dedicated astro cameras and DSLRs\/mirrorless bodies.\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\u003eUltraCat 108 vs. Takahashi FSQ-106EDX4: Aperture and Inclusions\u003c\/h3\u003e\n\u003cp\u003eThe Takahashi FSQ-106EDX4 is an industry benchmark, known for its impeccable optical quality and the ability to achieve a massive 88mm image circle with its dedicated reducer. It sets a high standard for flat-field performance.\u003c\/p\u003e\n\u003cp\u003eThe William Optics UltraCat 108 presents a compelling alternative focused on aperture and out-of-the-box functionality. It offers a larger 108mm aperture and a slightly faster native f\/4.8 focal ratio. Crucially, the UltraCat 108 includes a rotator, tilt adapter, multiple camera adapters, mounting rings, and a carrying case as standard, components that are often costly add-ons for other premium systems. This makes the UltraCat 108 a complete, ready-to-image package for the advanced astrophotographer seeking exceptional value and capability.\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\"\u003eDoes the William Optics UltraCat 108 require a field flattener?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo. The UltraCat 108 uses a 5-element Petzval optical design, which has a built-in field flattener. It is engineered to deliver a flat 60mm image circle with no additional optical correctors required.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the advantage of the WIFD focuser on the UltraCat 108?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe William Optics Internal Focuser Design (WIFD) moves optical elements internally to achieve focus, rather than moving the camera externally. This offers two key advantages:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eNo Sag or Flexure:\u003c\/strong\u003e Your camera and filter wheel are attached to a solid, fixed point, eliminating sag that can cause tilted images.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStable Balance:\u003c\/strong\u003e Since the heavy imaging payload doesn't move, the telescope's balance on the mount remains constant throughout the 30mm of focus travel.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the UltraCat 108's 60mm image circle benefit imaging the Andromeda Galaxy (M31) with a full-frame camera?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eA full-frame sensor has a diagonal of approximately 43mm. The UltraCat 108's massive 60mm image circle completely illuminates this sensor with high-quality, pinpoint stars from edge to edge. When imaging a large target like the Andromeda Galaxy (M31), this ensures you can capture its full expanse and surrounding dust lanes without vignetting or distorted stars in the corners of your frame.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat do I need to attach my ZWO camera with a filter wheel to the UltraCat 108?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe UltraCat 108 comes with M48, M54, and M68 adapters, making it ready for most standard ZWO camera and filter wheel combinations. You will use the appropriate adapter to connect to your filter wheel, ensuring you maintain the correct back focus for a flat field. The included Sensor Tilt Xterminator allows you to make fine adjustments for perfect sensor alignment.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the 7.96 kg OTA weight of the UltraCat 108 suitable for a mount like the Sky-Watcher EQ6-R Pro?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The Sky-Watcher EQ6-R Pro typically has a payload capacity of around 20 kg (44 lbs). The UltraCat 108's total weight with rings and dovetail is 9.58 kg (21.12 lbs). Even after adding a guide scope, camera, and other accessories, the total weight will remain well within the imaging payload limit of an EQ6-R Pro or similar class mount, ensuring stable and accurate tracking.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat are the included M48, M54, and M68 adapters for?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThese are different-sized threaded adapters to connect various cameras and accessories. \u003cstrong\u003eM48\u003c\/strong\u003e is the most common standard for 2\" filters and full-frame camera connections. \u003cstrong\u003eM54\u003c\/strong\u003e and \u003cstrong\u003eM68\u003c\/strong\u003e are larger-diameter threads used on many large-format astronomy cameras and accessories to prevent vignetting and provide a more secure connection for heavy imaging trains.\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\u003e5-Element Advanced Petzval\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOptical Elements\u003c\/td\u003e\n\u003ctd\u003e5 elements including 2x Super ED, 1x ED, 1x Lanthanum, and 1x X-Element glass\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDiameter\u003c\/td\u003e\n\u003ctd\u003e108 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Length\u003c\/td\u003e\n\u003ctd\u003e518 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Ratio\u003c\/td\u003e\n\u003ctd\u003ef\/4.8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eImage Circle\u003c\/td\u003e\n\u003ctd\u003e60 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocuser\u003c\/td\u003e\n\u003ctd\u003eWIFD Rack \u0026amp; Pinion Focuser\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocuser Compatibility\u003c\/td\u003e\n\u003ctd\u003eCompatible with ZWO EAF\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocuser Travel\u003c\/td\u003e\n\u003ctd\u003e30 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eField Flattener\u003c\/td\u003e\n\u003ctd\u003eNot Required\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCamera Format Support\u003c\/td\u003e\n\u003ctd\u003eMedium Format, Full Frame, APS-C, M4\/3\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eT-Mount Support\u003c\/td\u003e\n\u003ctd\u003eCanon EF, RF; Nikon F, Z; Sony E; Pentax K; MFT (M4\/3); FUJI X\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDovetail Type\u003c\/td\u003e\n\u003ctd\u003eLosmandy-style\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTube Length\u003c\/td\u003e\n\u003ctd\u003e512.9 mm - 617.9 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOTA Weight\u003c\/td\u003e\n\u003ctd\u003e7.96 kg (17.55 lbs)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTotal Weight\u003c\/td\u003e\n\u003ctd\u003e9.58 kg (21.12 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\"\u003eUltraCat 108 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 Focusing Mask 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\"\u003eMounting Rings \u0026amp; Handlebar\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\"\u003eSensor Tilt Xterminator \u0026amp; Rotator\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\"\u003eM68, M54, M48 Camera Adapters\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\"\u003eVixen-style 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\"\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":"Default Title","offer_id":50180567367965,"sku":"WO-T-C-108BR","price":5517.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/William-Optics-UltraCat-108-1.jpg?v=1753236705"},{"product_id":"william-optics-ultracat-56-f-4-8-wifd","title":"William Optics UltraCat 56 f\/4.8 WIFD","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e56mm Aperture, 269mm Focal Length (f\/4.8)\u003c\/li\u003e\n\u003cli\u003e5-Element Advanced Petzval Optical Design\u003c\/li\u003e\n\u003cli\u003e50mm Image Circle for Full-Frame Sensors\u003c\/li\u003e\n\u003cli\u003eWilliam Optics Internal Focus Design (WIFD)\u003c\/li\u003e\n\u003cli\u003eWeighs only 2.56 kg (5.64 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 UltraCat 56 f\/4.8 WIFD Astrograph\u003c\/h2\u003e\n\u003cp\u003eThe William Optics UltraCat 56 f\/4.8 WIFD integrates a 56mm aperture with a fast f\/4.8 focal ratio into a sophisticated 5-element Petzval design for portable wide-field imaging. Its 269mm focal length produces a massive 50mm image circle, fully illuminating full-frame sensors with perfectly flat fields and no additional flattener required. Weighing just 2.56 kg, this compact astrograph offers 0-30mm of precise internal focus travel, making it a definitive choice for capturing vast nebulae and stellar fields.\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\u003e5-Element Petzval Optics: A Flat 50mm Image Circle at f\/4.8\u003c\/h3\u003e\n\u003cp\u003eThe UltraCat 56's optical system is engineered to deliver a perfectly flat field across its entire 50mm image circle, eliminating the need for a separate field flattener. This 5-element Petzval design incorporates two Super ED glass elements, one ED element, and one Lanthanum element to achieve apochromatic color correction, rendering stars as sharp points with no distracting chromatic aberration.\u003c\/p\u003e\n\u003cp\u003eThe fast f\/4.8 focal ratio significantly reduces exposure times, allowing you to gather more signal on faint, expansive targets like the Andromeda Galaxy (M31) or the Rho Ophiuchi cloud complex in a single session. This combination of a wide, flat field and fast optics makes the UltraCat 56 an ideal instrument for full-frame and APS-C DSLR or dedicated astronomy cameras.\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: 30mm of Travel with Integrated Rotation \u0026amp; Tilt\u003c\/h3\u003e\n\u003cp\u003eAt the heart of the imaging train is the William Optics Internal Focus Design (WIFD), a robust rack-and-pinion mechanism that moves the lens elements internally. This design provides 30mm of precise focus travel without any external tube extension, preventing focuser sag and maintaining perfect balance, which is critical when using an electronic autofocuser (EAF).\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eIntegrated Rotator:\u003c\/strong\u003e The included 360° rotator allows for effortless camera framing without loosening any threaded connections, preserving optical alignment.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSensor Tilt Adjuster:\u003c\/strong\u003e A built-in tilt adapter lets you fine-tune your camera's sensor plane to be perfectly orthogonal to the optical axis, ensuring sharp stars across the entire frame.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBahtinov Mask Cap:\u003c\/strong\u003e The lens cap features an integrated Bahtinov mask, providing a simple and highly accurate tool for achieving critical focus every time.\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\u003e2.56 kg Portability with Vixen\/Arca-Swiss Compatibility\u003c\/h3\u003e\n\u003cp\u003eEngineered for imagers on the go, the UltraCat 56 OTA weighs only 2.56 kg (5.64 lbs). This low weight makes it an excellent match for portable tracking mounts and simplifies setup and transport for field use. The entire package, including rings and dovetail, comes in at a mere 3.21 kg.\u003c\/p\u003e\n\u003cp\u003eThe instrument includes a dual-function dovetail plate that is compatible with both traditional Vixen-style saddles and modern Arca-Swiss tripod heads, offering maximum mounting flexibility. The patented William Optics handle bar not only provides a secure grip but also serves as a mounting point for guide scopes or other accessories, while the included soft carry case protects the telescope during travel and storage.\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\u003eUltraCat 56 vs. RedCat 51: Aperture and Image Circle\u003c\/h3\u003e\n\u003cp\u003eWhile the RedCat 51 has established itself as a benchmark for ultra-portable astrographs, the UltraCat 56 offers key advantages for imagers seeking more light-gathering power and wider field coverage.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eRedCat 51 Advantage:\u003c\/strong\u003e The RedCat 51 is slightly smaller, lighter, and has a proven track record as one of the most popular portable imaging refractors available.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUltraCat 56 Advantage:\u003c\/strong\u003e The UltraCat 56 features a larger 56mm aperture compared to the RedCat's 51mm, providing a 20% increase in light-gathering area. Its 50mm image circle is also significantly larger than the RedCat's 44mm circle, offering superior illumination and less vignetting for full-frame and larger sensors.\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 UltraCat 56's Petzval design special?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003e5-element Petzval design\u003c\/strong\u003e has a field-correcting lens group built directly into the optical tube. This means you get a perfectly flat field, sharp to the edge, without needing to purchase, space, or configure a separate field flattener. It simplifies your imaging train and guarantees optimal performance out of the box.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the UltraCat 56 WIFD focuser compatible with a ZWO EAF?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, the William Optics Internal Focus Design (WIFD) focuser is fully compatible with the ZWO Electronic Automatic Focuser (EAF) and other popular EAF systems. The internal focusing mechanism prevents sag and maintains balance, making it an ideal platform for automated focusing routines.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow will the UltraCat 56 perform on the North America Nebula (NGC 7000) with a full-frame camera?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe UltraCat 56 is perfectly suited for this target. Its 269mm focal length and 50mm image circle will allow a full-frame sensor to capture the entire North America Nebula and the adjacent Pelican Nebula (IC 5070) in a single frame with excellent, pinpoint stars across the field. The fast f\/4.8 ratio will also help capture the faint hydrogen-alpha emissions with shorter sub-exposures.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the UltraCat 56 on a lightweight star tracker?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eAbsolutely. With a total weight of only \u003cstrong\u003e3.21 kg (7.08 lbs)\u003c\/strong\u003e including the ring and dovetail, the UltraCat 56 is well within the capacity of most premium portable star trackers like the Sky-Watcher Star Adventurer GTi or iOptron SkyGuider Pro. Its compact size and internal focusing make it a very stable and manageable load.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the purpose of the included Sensor Tilt Xterminator on the UltraCat 56?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Sensor Tilt Xterminator is a built-in tilt adjuster. It allows you to make micro-adjustments to the angle of your camera sensor relative to the telescope's focal plane. This is used to correct for any slight sensor tilt in your camera, ensuring that you can achieve perfectly sharp, round stars in all four corners of your image.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat do I need to connect my Canon RF-mount camera to the UltraCat 56?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe UltraCat 56 includes M48 and M54 camera adapters. To connect a specific camera brand, you will need a separate, camera-specific M48 or M54 T-ring. For a Canon RF-mount camera, you would need an M48-to-Canon-RF adapter, which is widely available.\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\u003e5-Element Advanced Petzval\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLens Elements\u003c\/td\u003e\n\u003ctd\u003eSuper ED Glass x2, ED Glass x1, Lanthanum Glass x1, X-Element x1\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDiameter\u003c\/td\u003e\n\u003ctd\u003e56 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Length\u003c\/td\u003e\n\u003ctd\u003e269 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Ratio\u003c\/td\u003e\n\u003ctd\u003ef\/4.8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eImage Circle\u003c\/td\u003e\n\u003ctd\u003e50 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocuser\u003c\/td\u003e\n\u003ctd\u003eWIFD Rack \u0026amp; Pinion Focuser (EAF Compatible)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocuser Travel\u003c\/td\u003e\n\u003ctd\u003e0-30 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFlattener Requirement\u003c\/td\u003e\n\u003ctd\u003eNo Flattener Required\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\u003eT-Mount Camera Support\u003c\/td\u003e\n\u003ctd\u003eCanon EF, RF, Nikon F, Z, Sony E, Pentax K, MFT (M4\/3), FUJI X\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDovetail Type\u003c\/td\u003e\n\u003ctd\u003eVixen \/ Arca-Swiss Dual Plate\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTube Length\u003c\/td\u003e\n\u003ctd\u003e296.3 mm - 348.3 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOTA Weight\u003c\/td\u003e\n\u003ctd\u003e2.56 kg (5.64 lbs)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTotal Weight\u003c\/td\u003e\n\u003ctd\u003e3.21 kg (7.08 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\"\u003eUltraCat 56 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 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\"\u003eMounting Ring \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\"\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\"\u003eSensor Tilt Xterminator Rotator\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\"\u003eM54 \u0026amp; M48 Camera Adapters\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\"\u003eAdapter Wrench\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\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\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":"Default Title","offer_id":50846087184669,"sku":"WO-T-C-56BR","price":1929.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/William-Optics-UltraCat-56-WIFD-1.jpg?v=1768578664"},{"product_id":"william-optics-ultracat-76-f-4-8-wifd","title":"William Optics UltraCat 76 f\/4.8 WIFD","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e76 mm Aperture, 365 mm Focal Length (f\/4.8)\u003c\/li\u003e\n\u003cli\u003e5-Element Advanced Petzval Optical Design\u003c\/li\u003e\n\u003cli\u003e50 mm Corrected Image Circle\u003c\/li\u003e\n\u003cli\u003eWilliam Optics Internal Focusing Design (WIFD)\u003c\/li\u003e\n\u003cli\u003eTotal Weight of 4.98 kg (10.98 lbs)\u003c\/li\u003e\n\u003cli\u003eDual Vixen\/Arca-Swiss Dovetail Plate\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 UltraCat 76 f\/4.8 WIFD\u003c\/h2\u003e\n\u003cp\u003eThe William Optics UltraCat 76 f\/4.8 WIFD integrates a 5-element Petzval optical system into a portable 76 mm aperture refractor, delivering a perfectly flat 50 mm image circle without an external flattener. Its fast f\/4.8 focal ratio and 365 mm focal length are engineered for wide-field deep-sky imaging, capturing immense targets on full-frame sensors. The entire imaging package, weighing only 4.98 kg, is built around an internal focuser design to eliminate sag and maintain perfect balance.\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\u003e5-Element Petzval Optics: A 50mm Flat Field with No Flattener\u003c\/h3\u003e\n\u003cp\u003eThe core of the UltraCat 76 is its advanced 5-element Petzval lens system, which uses two Super ED, one ED, and one Lanthanum glass element to achieve outstanding apochromatic color correction. This design naturally corrects for field curvature, producing pinpoint stars across a massive 50 mm image circle, fully illuminating full-frame and even larger sensors without vignetting. By eliminating the need for a separate flattener, your imaging train is simpler, lighter, and more rigid.\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: 20mm Internal Travel with Integrated Tilt Control\u003c\/h3\u003e\n\u003cp\u003eWilliam Optics' patented Internal Focusing Design (WIFD) moves the optical assembly internally, preventing the drawtube sag and balance shift common with external focusers. With 20 mm of precise travel, the rack-and-pinion mechanism is compatible with EAF systems for automated focusing. The entire focuser assembly includes a camera rotator for framing, M48 and M54 adapters, and the Sensor Tilt Xterminator, giving you complete control over your imaging train for perfectly flat and sharp fields.\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\u003eEngineered for Portability: 4.98 kg Total Weight and Vixen\/Arca-Swiss Plate\u003c\/h3\u003e\n\u003cp\u003eDesigned for field use, the UltraCat 76 has a total weight of just 4.98 kg (10.98 lbs) with rings and dovetail attached. This makes it an ideal match for modern portable equatorial mounts. The included dual-side dovetail plate offers native Vixen and Arca-Swiss compatibility, allowing you to mount it on virtually any astronomical or photographic tripod head without extra hardware. The package includes a patented handle bar, riser blocks for optimal balancing, and a soft carry case for transport and storage.\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\"\u003eWhy doesn't the William Optics UltraCat 76 need a field flattener?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe UltraCat 76 uses a \u003cstrong\u003e5-element Petzval optical design\u003c\/strong\u003e. This advanced configuration has corrective elements built into the rear of the optical tube, which naturally corrects for field curvature. This provides a flat 50 mm image circle without the need for an external flattener, simplifying your setup.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the UltraCat 76's 50mm image circle perform with a full-frame camera on the North American Nebula (NGC 7000)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe 50 mm image circle is significantly larger than a standard full-frame sensor (43mm diagonal), ensuring the entire sensor is fully illuminated with no vignetting. Paired with the 365 mm focal length, you can easily capture the entire North American Nebula (NGC 7000) and the adjacent Pelican Nebula (IC 5070) in a single, sharp, flat frame.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the UltraCat 76's WIFD focuser compatible with a ZWO EAF?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, the William Optics Internal Focusing Design (WIFD) is fully compatible with the ZWO EAF and other popular electronic automatic focusers. The internal rack-and-pinion mechanism provides the stability and precision required for automated focusing routines.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the advantage of the UltraCat 76's internal focuser design?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe WIFD moves the optics internally rather than extending a drawtube. This offers two key advantages:\n\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eNo Sag:\u003c\/strong\u003e It eliminates the potential for drawtube sag, which can cause image tilt with heavy camera setups.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStable Balance:\u003c\/strong\u003e Since the overall length of the telescope doesn't change during focusing, the center of balance remains constant, preventing tracking issues.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow do I use the Sensor Tilt Xterminator included with the UltraCat 76?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe included Sensor Tilt Xterminator is a tilt adapter that sits in the imaging train. It has adjustment screws that allow you to make minute changes to the camera sensor's angle relative to the optical axis. This lets you correct for any sensor tilt, ensuring perfectly sharp stars from corner to corner of your image.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat camera mounts are supported by the UltraCat 76?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe UltraCat 76 includes M48 and M54 camera adapters, and supports a wide range of T-mounts for direct connection to popular DSLR and mirrorless cameras. Supported systems include \u003cstrong\u003eCanon EF, RF, Nikon F, Z, Sony E, Pentax K, MFT (M4\/3), and FUJI X\u003c\/strong\u003e.\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\u003e5-Element Advanced Petzval\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLens Elements\u003c\/td\u003e\n\u003ctd\u003eSuper ED Glass x2, ED Glass x1, Lanthanum Glass x1, X-Element x1\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDiameter\u003c\/td\u003e\n\u003ctd\u003e76 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Length\u003c\/td\u003e\n\u003ctd\u003e365 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Ratio\u003c\/td\u003e\n\u003ctd\u003ef\/4.8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eImage Circle\u003c\/td\u003e\n\u003ctd\u003e50 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocuser\u003c\/td\u003e\n\u003ctd\u003eWIFD Rack \u0026amp; Pinion Focuser\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocuser Compatibility\u003c\/td\u003e\n\u003ctd\u003eEAF Compatible\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocuser Travel\u003c\/td\u003e\n\u003ctd\u003e0-20 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFlattener Requirement\u003c\/td\u003e\n\u003ctd\u003eNo Flattener Required\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\u003eT-Mount Support\u003c\/td\u003e\n\u003ctd\u003eCanon EF, RF; Nikon F, Z; Sony E; Pentax K; MFT (M4\/3); FUJI X\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDovetail Type\u003c\/td\u003e\n\u003ctd\u003eVixen \/ Arca-Swiss Dual Plate\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTube Length\u003c\/td\u003e\n\u003ctd\u003e363 mm - 415 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOTA Weight\u003c\/td\u003e\n\u003ctd\u003e3.81 kg \/ 8.4 lbs\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTotal Weight\u003c\/td\u003e\n\u003ctd\u003e4.98 kg \/ 10.98 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\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eUltraCat 76 Main Tube\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eBahtinov Cap\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eMounting Ring \u0026amp; Handle bar\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\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\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eRiser Blocks\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eSensor Tilt Xterminator Rotator\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eM54 \u0026amp; M48 Camera Adapters\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eM48, M54 Adapter Wrench\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\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\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\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\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":"Default Title","offer_id":50846093934877,"sku":"WO-T-C-76BR","price":3033.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/William-Optics-UltraCat-76-WIFD-1.jpg?v=1768578903"},{"product_id":"william-optics-t-c-131br","title":"William Optics Ultra-Cat 131 f\/4.9 Petzval Astrograph","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e131mm Aperture\u003c\/li\u003e\n\u003cli\u003e648mm Focal Length (f\/4.9)\u003c\/li\u003e\n\u003cli\u003e5-Element Advanced Petzval Optical Design\u003c\/li\u003e\n\u003cli\u003e60mm Flat-Field Image Circle\u003c\/li\u003e\n\u003cli\u003ePatented WIFD Internal Focuser\u003c\/li\u003e\n\u003cli\u003e13.97 kg Total Weight\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 Ultra-Cat 131 f\/4.9 Petzval Astrograph\u003c\/h2\u003e\n\u003cp\u003eThe William Optics Ultra-Cat 131 combines a massive 131mm aperture with a fast f\/4.9 focal ratio, delivering exceptional light-gathering power for serious deep-sky imagers. Its 5-element Petzval optical system produces a completely flat 60mm image circle without an external flattener, fully illuminating medium-format sensors. With a native 648mm focal length and a total weight of 13.97 kg, this astrograph is engineered for capturing vast, high-resolution celestial portraits with pinpoint stars from edge to edge.\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\u003eFlagship 131mm Petzval Optics: A 60mm Flat-Field Image Circle\u003c\/h3\u003e\n\u003cp\u003eThe optical core of the Ultra-Cat 131 is an advanced 5-element Petzval design featuring two Super ED elements, one ED element, and one Lanthanum element. This sophisticated configuration eliminates the need for a separate field flattener, correcting for field curvature and chromatic aberration natively to produce a perfectly flat 60mm image circle. This allows you to place your medium-format or full-frame sensor anywhere within the field and achieve sharp, perfectly formed stars.\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\u003ePatented WIFD Focuser: 20mm of Zero-Shift Internal Focus\u003c\/h3\u003e\n\u003cp\u003eWilliam Optics' patented WIFD (William Optics Internal Focuser Design) provides 20mm of precise focus travel without any external drawtube movement. By moving the optics internally, the system completely avoids the balance shifts, flexure, and vignetting common with traditional focusers. This robust design maintains perfect optical alignment and rigidity, even when loaded with heavy imaging trains, and is fully compatible with electronic auto-focusers (EAF).\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\u003eObservatory-Grade Build: 13.97 kg of Stability and Broad Camera Support\u003c\/h3\u003e\n\u003cp\u003eEngineered for thermal stability and mechanical rigidity, the Ultra-Cat 131 weighs in at a substantial 13.97 kg with all accessories. It ships with robust mounting rings and a Losmandy-style dovetail plate for secure attachment to observatory-class mounts. The package includes a comprehensive set of M68, M54, and M48 camera adapters and a Sensor Tilt Xterminator (STX-R), ensuring you can achieve perfect sensor alignment with virtually any Canon, Nikon, Sony, or dedicated astronomy camera.\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\u003eUltra-Cat 131 vs. 106mm Refractors: The Aperture Advantage\u003c\/h3\u003e\n\u003cp\u003eWhen compared to premium 106mm refractors, the Ultra-Cat 131's primary advantage is its sheer light-gathering power and field coverage. The difference in aperture provides a significant boost in signal for faint deep-sky targets.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eLight Gathering:\u003c\/strong\u003e The 131mm objective collects over 50% more light than a 106mm objective, allowing you to capture fainter details in the same exposure time or significantly shorten your sub-exposures.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eImage Circle:\u003c\/strong\u003e The Ultra-Cat's native 60mm flat image circle dwarfs the 44mm circle typical of full-frame-corrected 106mm scopes, providing superior illumination and vignetting control for large sensors.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIntegrated Design:\u003c\/strong\u003e While many refractors require a separate, carefully spaced flattener, the Ultra-Cat 131's Petzval design is inherently corrected, simplifying your imaging train and eliminating a potential source of tilt and error.\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\"\u003eHow does the Ultra-Cat 131's 60mm image circle benefit imaging the Andromeda Galaxy (M31) with a full-frame camera?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Andromeda Galaxy is a massive target. The Ultra-Cat 131's 648mm focal length and 60mm image circle allow you to frame the entire galaxy, including its faint outer arms and satellite galaxies M32 and M110, on a full-frame sensor with excellent illumination and sharp stars right to the corners of the frame. A smaller image circle would introduce significant vignetting, darkening the edges and losing crucial detail.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat class of mount is required for the 13.97 kg total weight of the Ultra-Cat 131?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWith a total weight of 13.97 kg (30.8 lbs), plus the weight of your camera, guide scope, and other accessories, you will need a robust equatorial mount with a payload capacity of at least 50-60 lbs (22-27 kg) for reliable astrophotography. Mounts in the Sky-Watcher EQ6-R Pro, iOptron CEM60\/70, or Losmandy G11 class are recommended for stable, long-exposure imaging with the Ultra-Cat 131.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDo I need a separate field flattener for the Ultra-Cat 131?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo. The Ultra-Cat 131 uses an advanced 5-element Petzval optical design that has field flattening built-in. It produces a perfectly flat 60mm image circle without the need for any additional flattener or reducer, simplifying your imaging train.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the WIFD internal focuser on the Ultra-Cat 131 improve imaging sessions?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe WIFD (William Optics Internal Focuser Design) offers two key advantages. First, because only internal optical elements move, the overall length of the telescope never changes. This keeps the balance point constant, preventing tracking errors as you cross the meridian. Second, it eliminates drawtube sag, a common problem with heavy cameras on traditional focusers, ensuring your sensor remains perfectly orthogonal to the light path.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the f\/4.9 focal ratio of the Ultra-Cat 131 fast enough for narrowband imaging of targets like the Elephant's Trunk Nebula (IC 1396)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eAbsolutely. An f\/4.9 focal ratio is considered very fast for astrophotography. This speed allows you to collect a strong signal with narrowband filters (like H-alpha, OIII, and SII) in a fraction of the time it would take with a slower f\/7 or f\/8 system, making it ideal for capturing deep, high-contrast images of emission nebulae like IC 1396.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the purpose of the included Sensor Tilt Xterminator (STX-R) with the Ultra-Cat 131?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Sensor Tilt Xterminator (STX-R) is a precision tilt adapter. It allows you to make minute adjustments to the angle of your camera sensor relative to the telescope's optical axis. This is crucial for achieving perfectly sharp stars across a large, flat field, as it corrects for any slight tilt that may exist in your camera or focuser.\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\u003eOptical Design\u003c\/td\u003e\n\u003ctd\u003e5-Element Advanced Petzval\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLens Elements\u003c\/td\u003e\n\u003ctd\u003eSuper ED Glass x2, ED Glass x1, Lanthanum Glass x1, X-Element x1\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDiameter\u003c\/td\u003e\n\u003ctd\u003e131 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Length\u003c\/td\u003e\n\u003ctd\u003e648 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Ratio\u003c\/td\u003e\n\u003ctd\u003ef\/4.9\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eImage Circle\u003c\/td\u003e\n\u003ctd\u003e60 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocuser\u003c\/td\u003e\n\u003ctd\u003eWIFD Rack \u0026amp; Pinion Internal Focuser, EAF Compatible\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocuser Travel\u003c\/td\u003e\n\u003ctd\u003e0-20 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFlattener Required\u003c\/td\u003e\n\u003ctd\u003eNo\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSupported Camera Formats\u003c\/td\u003e\n\u003ctd\u003eMedium Format, Full Frame, APS-C, M4\/3\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSupported T-Mounts\u003c\/td\u003e\n\u003ctd\u003eCanon EF, RF; Nikon F, Z; Sony E; Pentax K; MFT (M4\/3); FUJI X\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDovetail Type\u003c\/td\u003e\n\u003ctd\u003eLosmandy\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTube Length (Retracted\/Extended)\u003c\/td\u003e\n\u003ctd\u003e650 mm - 785.5 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOTA Weight\u003c\/td\u003e\n\u003ctd\u003e11.3 kg \/ 24.91 lbs\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTotal Weight\u003c\/td\u003e\n\u003ctd\u003e13.97 kg \/ 30.8 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\"\u003eUltra-Cat 131 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 Focus Aid 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\"\u003eSensor Tilt Xterminator (STX-R)\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\"\u003eM68, M54, and M48 Camera Adapters\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\"\u003eLosmandy-Style Dovetail 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\"\u003eSoft Padded 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 \u0026amp; Wrench\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\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":"Default Title","offer_id":52853689057565,"sku":"WO-T-C-131BR","price":7449.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/WilliamOptics-Ultra-Cat-131-1_4421596a-b1ce-428f-84ff-326b3a644d9a.jpg?v=1788457750"}],"url":"https:\/\/davidastro.com\/en-us\/collections\/william-optics-ultracat-astrographs.oembed","provider":"David Astro","version":"1.0","type":"link"}