{"product_id":"svbony-mk90-maksutov-cassegrain-telescope","title":"SVBONY MK90 90mm f\/13.9 Maksutov-Cassegrain Telescope OTA","description":"\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6386763495481873639879280.jpg?v=1791670108\" alt=\"SVBONY MK90 90mm Maksutov-Cassegrain telescope key visual\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe SVBONY MK90 is a compact 90 mm Maksutov-Cassegrain optical tube with a 1250 mm focal length at f\/13.9. A full-aperture meniscus corrector and a folded light path pack that long focal length into a short, closed tube, which suits high-magnification views of the Moon and planets as well as daytime nature viewing.\u003c\/p\u003e\n\u003cp\u003eSVBONY collimates each tube at the factory through a three-stage process, fits a tapered internal baffle to cut stray light, and supplies a 70 mm Vixen-style dovetail plate on a mounting base. The tube weighs 1380 g, and the rear port takes T-ring and camera adapters on its M42 × 0.75 thread.\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThis is a good match if you:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eWant a small scope for the Moon and planets:\u003c\/strong\u003e 1250 mm of focal length gives high magnification with ordinary eyepieces.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTravel or observe from a balcony:\u003c\/strong\u003e at 1380 g the MK90 sits on light photo tripods and small alt-az mounts.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWatch birds and wildlife by day:\u003c\/strong\u003e the closed tube and long focal length make it a capable long-range terrestrial scope with an erecting diagonal.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAre choosing a first telescope:\u003c\/strong\u003e there is no collimation to learn and nothing to align before observing.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e90 mm aperture, 1250 mm focal length:\u003c\/strong\u003e f\/13.9 native, rated by SVBONY at 180x light-gathering power.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNo periodic collimation:\u003c\/strong\u003e the meniscus corrector replaces a Schmidt plate, and the optics are set at the factory and held by three fixing screws and three pairs of collimation screws.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTapered baffle tube:\u003c\/strong\u003e blocks and absorbs stray light for higher image contrast.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInternal focuser:\u003c\/strong\u003e focus is set by moving the primary mirror, so nothing extends from the rear of the tube.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCoatings:\u003c\/strong\u003e multi-coated precision aluminium coating on the primary; aluminium plus multi-coating on the secondary, with SVBONY quoting over 89% reflectance.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMetal construction:\u003c\/strong\u003e a sturdy tube built for travel.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6386763502694863351849700.jpg?v=1791670108\" alt=\"SVBONY MK90 design craftsmanship and tapered baffle tube\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6386763506148697666431374.jpg?v=1791670108\" alt=\"SVBONY MK90 fixing and collimation screws close-up\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6386763506185660411818477.jpg?v=1791670108\" alt=\"SVBONY MK90 dovetail mounting base close-up\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eOptical Design\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eLight passes through the meniscus corrector, reflects from the spherical primary, and returns through the central hole in the primary after bouncing off the secondary. SVBONY describes the MK90 as a two-element Maksutov-Cassegrain optical system. Because the image is formed by mirrors, all colours come to the same focus, and the closed tube keeps dust and air currents away from the optics.\u003c\/p\u003e\n\u003cp\u003eThe long f\/13.9 focal ratio keeps the field narrow and the image scale large, which is what you want for lunar craters, Jupiter's belts and Saturn's rings, and it is forgiving of eyepiece design at the edges of the field.\u003c\/p\u003e\n\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6386763472145560026834430.jpg?v=1791670108\" alt=\"SVBONY MK90 Maksutov-Cassegrain optical design for image contrast\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eLunar and planetary observing:\u003c\/strong\u003e high magnification for crater detail, planetary discs and Saturn's rings.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDouble stars:\u003c\/strong\u003e a large image scale for splitting close pairs.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDaytime nature observation:\u003c\/strong\u003e birds, wildlife and distant landscapes with an erecting diagonal.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLunar and planetary imaging:\u003c\/strong\u003e a T-ring or camera adapter threads to the M42 × 0.75 rear port.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6386763475686847706311491.jpg?v=1791670108\" alt=\"SVBONY MK90 lunar, planetary and terrestrial observation uses\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eRear thread:\u003c\/strong\u003e M42 × 0.75 for T-rings and camera adapters.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMounting:\u003c\/strong\u003e a 70 mm, 75° Vixen-standard dovetail plate on a versatile mounting base, plus a UNC 1\/4″-20 photographic thread for direct mounting on a camera tripod.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eVisual accessories:\u003c\/strong\u003e a 1.25″ diagonal and eyepieces are needed for visual use; neither is included with the OTA.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCombination sets:\u003c\/strong\u003e SVBONY also offers the MK90 as a mini mount and tripod set, a visual observation set, an EAA set and a birdwatching kit. This listing is the OTA; ask us if you would like one of the sets.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6386763506217547188118787.jpg?v=1791670108\" alt=\"SVBONY MK90 UNC 1\/4-20 photo thread and 70mm Vixen dovetail plate\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6386763480413916913839989.jpg?v=1791670108\" alt=\"SVBONY MK90 combination bundle options\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6386763480448095906132791.jpg?v=1791670108\" alt=\"SVBONY MK90 combination bundle accessories\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6387245933291949295291709.jpg?v=1791670108\" alt=\"SVBONY MK90 combination set overview\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eWhat's in the Box\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e1 x MK90 Maksutov-Cassegrain OTA\u003c\/li\u003e\n\u003cli\u003e1 x versatile dovetail mounting base\u003c\/li\u003e\n\u003cli\u003e1 x Vixen-style dovetail plate, 70 mm\u003c\/li\u003e\n\u003cli\u003e1 x objective lens cover\u003c\/li\u003e\n\u003cli\u003e1 x 1.25″ dust plug\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cstrong\u003eGood to Know Before You Order\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eOptical tube only:\u003c\/strong\u003e no mount, tripod, diagonal or eyepiece is included. The dovetail and 1\/4″-20 thread fit most small mounts and photo tripods.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNarrow field:\u003c\/strong\u003e at f\/13.9 the MK90 frames planets and lunar detail rather than large star fields.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCool-down:\u003c\/strong\u003e like any closed-tube Maksutov it gives its sharpest views once the optics reach outdoor temperature, so setting it out a little before observing helps.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDew:\u003c\/strong\u003e the front meniscus faces the sky, and on humid nights a dew heater keeps it clear.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eIs it difficult to set up?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNo. The tube arrives collimated, the dovetail drops into any Vixen-style saddle or the base threads onto a photo tripod, and a diagonal and eyepiece complete it.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDoes it need collimation?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNo periodic collimation is needed. SVBONY sets the optics at the factory and the meniscus design holds alignment well.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan I use it for birdwatching?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eYes. SVBONY designs it for terrestrial nature observation as well as astronomy; an erecting diagonal gives a correctly oriented view.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan I attach a camera?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eYes. The rear port is M42 × 0.75, which takes a T-ring for a DSLR or mirrorless camera, or a planetary camera adapter.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHow heavy is it?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e1380 g, light enough for small alt-az mounts and sturdy photo tripods.\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eIn short: a 90 mm, 1250 mm f\/13.9 Maksutov-Cassegrain that arrives collimated, weighs 1380 g and mounts by Vixen dovetail or 1\/4″-20 thread. Add a diagonal, an eyepiece and a small mount for high-power lunar, planetary and nature viewing.\u003c\/p\u003e","brand":"SvBony","offers":[{"title":"MK90 OTA","offer_id":67722269294703,"sku":"F9382B","price":242.24,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/F9382B-0_20251231142606_8993.webp?v=1791670314","url":"https:\/\/ontariotelescope.com\/products\/svbony-mk90-maksutov-cassegrain-telescope","provider":"Ontario Telescope and Accessories","version":"1.0","type":"link"}