{"product_id":"william-optics-ultracat-56-wifd-petzval-apo-refractor-t-c-56","title":"William Optics UltraCat 56 f\/4.8 WIFD Petzval APO Refractor - T-C-56BR","description":"\u003cp style=\"text-align: center;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0851\/2766\/files\/UltraCat_56_Banner.png?v=1769111660\" alt=\"\"\u003e\u003c\/p\u003e\n\u003cp\u003eThe William Optics UltraCat 56 is a cutting-edge 56mm f\/4.8 apochromatic refractor designed for astrophotographers who demand top-tier performance. Featuring a 5-element advanced Petzval optical design and a fast f\/4.8 focal ratio, the UltraCat 56 delivers breathtaking edge-to-edge clarity and vivid detail without an additional flattener, making it perfect for capturing expansive celestial views. Its robust build, exceptional optics, and innovative features redefine the standard for astrophotography.\u003c\/p\u003e\n\u003cp style=\"text-align: center;\"\u003e\u003cimg alt=\"\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0851\/2766\/files\/UltraCat_56_Angle_Right.webp?v=1766509109\"\u003e\u003c\/p\u003e\n\u003ch3\u003eKey Features:\u003c\/h3\u003e\n\u003ch3 style=\"text-align: center;\"\u003e\u003cstrong\u003e\u003cimg alt=\"\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0851\/2766\/files\/Needs_No_Flattener.webp?v=1769112161\"\u003e\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eAdvanced 5-Element Petzval Design\u003cbr\u003e\u003c\/strong\u003eEliminates field curvature, providing sharp, flat-field images without requiring additional flatteners.\u003c\/p\u003e\n\u003cp style=\"text-align: center;\"\u003e\u003cimg alt=\"\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0851\/2766\/files\/FOV_Performance.webp?v=1769112161\"\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e50mm Image Circle\u003cbr\u003e\u003c\/strong\u003eFully supports full-frame and medium-format cameras for wide-field and detailed astrophotography.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eF\/4.8 Fast Optics\u003cbr\u003e\u003c\/strong\u003eOffers exceptional light-gathering capability for vibrant deep-sky photography.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWIFD (William’s Internal Focuser Design)\u003cbr\u003e\u003c\/strong\u003ePatented internal focuser ensures precise, stable, and hassle-free imaging, avoiding balance issues and eliminating vignetting. Zero image shift!\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eAnti-Shrink Lens Cell Technology\u003cbr\u003e\u003c\/strong\u003eMinimizes thermal expansion and contraction, maintaining perfect optical alignment in any environment.\u003c\/p\u003e\n\u003cp style=\"text-align: center;\"\u003e\u003cimg alt=\"\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0851\/2766\/files\/Tilt_Xterminator.webp?v=1769112161\"\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eSensor Tilt Xterminator\u003cbr\u003e\u003c\/strong\u003eIntegrated and patented design eliminates distortion, optimizing sharpness and detail for professional-level results.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eBuilt-In Patented Bahtinov Mask in Front Cap\u003cbr\u003e\u003c\/strong\u003eSimplifies focusing for pinpoint precision, a feature that sets it apart from competitors.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003ePatented Handle Bar Design\u003cbr\u003e\u003c\/strong\u003eCombines ergonomic usability with enhanced portability.\u003c\/p\u003e\n\u003ch3\u003eUltraCat 56 Specifications...\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eLens Type:\u003c\/strong\u003e 5-Element Advanced Petzval\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eFocal Length:\u003c\/strong\u003e 269 mm\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eLens Diameter:\u003c\/strong\u003e 56 mm\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eFocal Ratio:\u003c\/strong\u003e f\/4.8\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eFocuser:\u003c\/strong\u003e WIFD Rack \u0026amp; Pinion, compatible with EAF, 0-30mm focus travel\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eAdapters Included:\u003c\/strong\u003e Sensor Tilt Corrector\/Rotator, M68 to M48 Camera Adapter\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eOptional Flattener?\u003c\/strong\u003e No flattener required due to inherent flat field of this five-element Petzval scope. Backspacing calculations are a thing of the past as well! As long as your camera can reach focus, the entire frame will, too. You'll love the ease of set up and quality of the images!\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eCamera Format:\u003c\/strong\u003e Full Frame, APS-C, M 4\/3, Medium Format\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eTube Length (minimum and maximum):\u003c\/strong\u003e 11.7\" retracted, 12.7\" extended\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOTA Weight:\u003c\/strong\u003e 2.56 kg\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eWhat's in the Box?\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eUltraCat 56 OTA\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul\u003e\n\u003cli\u003eSensor Tilt Xterminator with integrated Rotator\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul\u003e\n\u003cli\u003eM68 to M48 Adapter\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul\u003e\n\u003cli\u003eRear Dust Cap\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul\u003e\n\u003cli\u003eObjective Cap with Bahtinov Mask for help with focusing\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul\u003e\n\u003cli\u003eTemperature Gauge built into coarse focus knob\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul\u003e\n\u003cli\u003eHandle Bar with top Vixen-Style dovetail for guidescope\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul\u003e\n\u003cli\u003e210mm Dovetail Plate - Two sided, Vixen \u0026amp; Arca-Swiss\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul\u003e\n\u003cli\u003eAllen Keys\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"William Optics","offers":[{"title":"Default Title","offer_id":42883054207089,"sku":"WIL-T-C-56BR","price":1237.95,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0851\/2766\/files\/UltraCat_56_Angle_Right.webp?v=1776459062","url":"https:\/\/khanscope.com\/fr-fr\/products\/william-optics-ultracat-56-wifd-petzval-apo-refractor-t-c-56","provider":"Khan Scope Centre","version":"1.0","type":"link"}