{"product_id":"william-optics-fluorostar-91-apo-refractor","title":"William Optics Fluorostar 91 APO Refractor","description":"\u003cp\u003eThe \u003cstrong\u003eWilliam Optics Fluorostar 91 APO\u003c\/strong\u003e is a premium 91mm f\/5.9 triplet apochromatic refractor designed for visual astronomy, portable observing, and high-quality deep-sky astrophotography. With a 540mm focal length, compact optical tube, and premium triplet design, it is a strong choice for customers who want serious refractor performance in a manageable size.\u003c\/p\u003e\u003ch2\u003eWho Is This Product Best For?\u003c\/h2\u003e\u003cp\u003eThe Fluorostar 91 is best for intermediate and advanced observers or astrophotographers who want a higher-performance triplet refractor than a compact entry-level APO. It is suitable for visual observing, lunar and planetary viewing, wide-field deep-sky imaging, and premium portable telescope setups.\u003c\/p\u003e\u003ch2\u003eWhy Choose This Product?\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e91mm triplet APO optics:\u003c\/strong\u003e Delivers strong colour correction and sharp image quality.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ef\/5.9 focal ratio:\u003c\/strong\u003e A versatile balance for visual observing and astrophotography.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e540mm focal length:\u003c\/strong\u003e Useful for nebulae, star fields, larger galaxies, and lunar observing.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePortable premium refractor:\u003c\/strong\u003e More capable than smaller travel scopes while still manageable on many mounts.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eImaging upgrade path:\u003c\/strong\u003e Pairs with compatible William Optics flatteners\/reducers for camera use.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eRecommended Uses\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eVisual astronomy\u003c\/li\u003e\n\u003cli\u003eWide-field and mid-field astrophotography\u003c\/li\u003e\n\u003cli\u003eLunar and planetary observing\u003c\/li\u003e\n\u003cli\u003ePremium portable refractor setups\u003c\/li\u003e\n\u003cli\u003eDeep-sky imaging with compatible flattener\/reducer\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eCompatibility and Accessory Notes\u003c\/h2\u003e\u003cp\u003eFor astrophotography, customers should pair the Fluorostar 91 with the appropriate William Optics flattener or reducer and confirm camera spacing, adapters, filter wheel clearance, focuser support, and mount capacity. For visual observing, use compatible diagonals and eyepieces.\u003c\/p\u003e\u003ch2\u003eImportant Limitations\u003c\/h2\u003e\u003cp\u003eThe Fluorostar 91 is more capable than compact travel refractors but still has a shorter focal length than dedicated planetary or small-galaxy telescopes. For best full-frame astrophotography performance, a matched field flattener or reducer is recommended.\u003c\/p\u003e\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\u003ch3\u003eIs the Fluorostar 91 good for beginners?\u003c\/h3\u003e\u003cp\u003eIt can be used by a beginner, but it is best for customers who want a premium refractor and are prepared to invest in a suitable mount and accessories.\u003c\/p\u003e\u003ch3\u003eCan it be used visually?\u003c\/h3\u003e\u003cp\u003eYes. The Fluorostar 91 can be used for visual observing with compatible diagonals and eyepieces.\u003c\/p\u003e\u003ch3\u003eCan it be used for astrophotography?\u003c\/h3\u003e\u003cp\u003eYes. It is well suited to astrophotography when paired with the appropriate flattener or reducer and a suitable tracking mount.\u003c\/p\u003e\u003ch2\u003eOur Recommendation\u003c\/h2\u003e\u003cp\u003eThe William Optics Fluorostar 91 APO is a strong choice for customers who want a premium portable triplet refractor for both observing and imaging. Choose it if you want better optical performance and more reach than a smaller travel scope while keeping the system manageable.\u003c\/p\u003e","brand":"William Optics","offers":[{"title":"Red","offer_id":53154229452911,"sku":"T-FLT-91RD-RP33-NEW","price":2797.2,"currency_code":"CAD","in_stock":true},{"title":"Gold","offer_id":53154229485679,"sku":"T-FLT-91GC-RP33-NEW","price":2797.2,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/william-optics-fluorostar-91-perspective-1.jpg?v=1779652911","url":"https:\/\/ontariotelescope.com\/products\/william-optics-fluorostar-91-apo-refractor","provider":"Ontario Telescope and Accessories","version":"1.0","type":"link"}