{"product_id":"svbony-sv198-50mm-mini-guide-scope","title":"SVBONY SV198 50mm f\/4.1 Mini Guide Scope with Dual Helical Focuser","description":"\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6387563931286448064024923.jpg?v=1791669935\" alt=\"SVBONY SV198 50mm mini guide scope key visual\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe SVBONY SV198 is a 50 mm f\/4.1 achromatic mini guide scope with a 206.6 mm focal length, a dual helical focuser with 12 mm of travel, and a Vixen-standard base. The eyepiece end takes 1.25″ eyepieces or guide cameras and also carries a T2 thread. A 45 mm T2 extension tube is included so insert-style guide cameras can reach focus. The aluminium tube is 55.5 mm in diameter and 234 mm long, and the scope weighs 557 g.\u003c\/p\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6387563931325728878034280.jpg?v=1791669935\" alt=\"SVBONY SV198 50mm guide scope aperture panel\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThis is a good match if you autoguide a deep-sky imaging rig and want more aperture than a 30 mm mini guider without the weight of a 60 mm scope, or if you want a finder that can double as a guide scope.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e50 mm, f\/4.1 achromat:\u003c\/strong\u003e 2-element \/ 1-group objective, fully multi-coated, with blackened lens edges.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e206.6 mm focal length:\u003c\/strong\u003e a longer guiding focal length than a 30 mm or 120 mm mini guider.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDual helical + telescopic focuser:\u003c\/strong\u003e 12 mm helical travel with a millimetre scale, so you can return to a known focus position.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1.25″ and T2 connection:\u003c\/strong\u003e accepts 1.25″ eyepieces and cameras, or threads on via T2.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eReduced internal reflections:\u003c\/strong\u003e SVBONY's internal design limits stray light for better contrast.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eVixen-standard base\u003c\/strong\u003e for direct mounting to a Vixen-style shoe.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6387563931360071581504472.jpg?v=1791669935\" alt=\"SVBONY SV198 guide scope 1.25 inch holder with T2 thread\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6387563931393575473185523.jpg?v=1791669935\" alt=\"SVBONY SV198 guide scope dual helical focuser with scale\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eOptical Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe SV198 uses a two-element, single-group achromatic objective at f\/4.1. For guiding, the relevant figures are aperture and focal length: 50 mm gathers more light than a 30 mm guider, so more guide stars are available in a given field, and 206.6 mm gives finer guiding resolution with a small-pixel guide camera. The millimetre scale on the helical focuser lets you note and return to your guide camera's focus position.\u003c\/p\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6387563931492471996558731.jpg?v=1791669935\" alt=\"SVBONY SV198 guide scope internal baffling for contrast\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eAutoguiding\u003c\/strong\u003e deep-sky imaging rigs with a 1.25″ guide camera such as the SVBONY SV905C or SV305, which SVBONY names as examples.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFinder use\u003c\/strong\u003e with a standard 1.25″ eyepiece when the extension tube is removed.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePlate-solving or polar-alignment camera\u003c\/strong\u003e on a portable setup.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6387563931425439843191668.jpg?v=1791669935\" alt=\"SVBONY SV198 guide scope 45mm extension with guide camera\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eGuide cameras:\u003c\/strong\u003e insert 1.25″ guide cameras use the included 45 mm extension tube (M42×0.75 male and female threads), which brings them to focus and, per SVBONY, reduces vignetting.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEyepieces:\u003c\/strong\u003e without the extension tube, standard 1.25″ eyepieces reach focus.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMounting:\u003c\/strong\u003e Vixen-standard base; dew cap diameter 58 mm.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHandle bar:\u003c\/strong\u003e SVBONY shows the SV198 seated on the SV211 handle bar, which has an integrated saddle for a guide or finder scope.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6387563931458597812417600.jpg?v=1791669935\" alt=\"SVBONY SV198 guide scope used with a 1.25 inch eyepiece\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\u003cp\u003eIf you are pairing it with a different guide camera, send us the camera model and we will confirm the focus position with you.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eWhat's in the Box\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eSV198 50 mm f\/4.1 mini guide scope\u003c\/li\u003e\n\u003cli\u003eLens bracket\u003c\/li\u003e\n\u003cli\u003e45 mm T2 extension tube\u003c\/li\u003e\n\u003cli\u003e1.25″ dust plug\u003c\/li\u003e\n\u003cli\u003eSilicone objective lens cover\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eGood to Know Before You Order\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eGuide camera sold separately.\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBackfocus:\u003c\/strong\u003e SVBONY does not publish a backfocus figure; the included 45 mm extension is what brings insert-style guide cameras to focus.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight 557 g:\u003c\/strong\u003e worth including in your mount payload alongside the main telescope and camera.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eIs it difficult to set up?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eNo. Mount it on a Vixen-style shoe, insert the guide camera with the 45 mm extension, focus on a bright star with the helical focuser and lock it.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow does it compare with the SV106 and SV165?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eSVBONY's comparison lists the SV198 at 50 mm and 206.6 mm (557 g), the SV106 at 60 mm and 240 mm (790 g), and the SV165 at 30 mm and 120 mm (342 g).\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan I use it as a finder?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eYes. Remove the extension tube and use a 1.25″ eyepiece.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhich guide cameras fit?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003e1.25″ insert-style cameras such as the SVBONY SV905C and SV305, or cameras with a T2 thread.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eIn short: a 50 mm f\/4.1 guide scope with a 206.6 mm focal length, a scaled dual helical focuser and both 1.25″ and T2 connections, supplied with the 45 mm extension that guide cameras need to reach focus.\u003c\/p\u003e","brand":"SvBony","offers":[{"title":"Default Title","offer_id":67722231808111,"sku":"W9155A","price":152.46,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/w9155a-1_20250807171914_4292_20260814160248_4545.webp?v=1791670140","url":"https:\/\/ontariotelescope.com\/products\/svbony-sv198-50mm-mini-guide-scope","provider":"Ontario Telescope and Accessories","version":"1.0","type":"link"}