{"product_id":"takahashi-98mm-rd-ext-33-2mm-adapter","title":"Takahashi 98mm RD-EXT 33.2mm Adapter","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThis is Takahashi's 98mm RD-EXT adapter, part TKA86205, built to the M98 thread Takahashi uses on its CCA-250 camera angle system and related Mewlon-250CRS accessories. Takahashi publishes a light path length of 33.2 mm for it — what it adds to the train, not its physical size — and at that length it's a meaningful spacing step in a 98 mm accessory chain, not just a coupling ring.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThis is a good match if you're assembling or extending a Takahashi 98 mm-thread accessory train — typically behind a CCA-250 camera angle adjuster — and need the 33.2 mm spacing step it provides.\u003c\/p\u003e\u003cp\u003eOn its own it doesn't do much: it's one link in a larger 98 mm-thread chain, not a stand-alone camera or eyepiece adapter.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e98 mm thread family:\u003c\/strong\u003e built to Takahashi's M98 interface, shared with the CCA-250 camera angle system.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e33.2 mm light path:\u003c\/strong\u003e Takahashi's published figure for what this ring contributes to the optical train.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePurely mechanical:\u003c\/strong\u003e a spacer\/coupling ring, with no optical element of its own.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eExtending a CCA-250 or Mewlon-250CRS camera angle train\u003c\/strong\u003e by the published 33.2 mm.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFilling a specific spacing gap\u003c\/strong\u003e in a 98 mm-thread accessory chain.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003ePart of the 98 mm (M98) Takahashi accessory family,\u003c\/strong\u003e the same thread standard used on the CCA-250 camera angle adjuster and its couplings.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAdds 33.2 mm to the optical train\u003c\/strong\u003e — the figure to check against your total spacing. Our \u003ca href=\"\/pages\/takahashi-back-focus-guide\"\u003eTakahashi Back Focus Guide\u003c\/a\u003e covers backfocus figures for Takahashi telescopes and their adapters.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePurely mechanical\u003c\/strong\u003e — no glass, no reduction, no correction.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eSend us the rest of your 98 mm accessory chain — CCA-250, couplings and camera — and we'll confirm exactly where this ring fits and whether it's the spacing step you need.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eGood to Know Before You Order\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eIt's a mechanical spacer,\u003c\/strong\u003e not an optical corrector — it doesn't change focal length or focal ratio.\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 — it's a threaded ring that installs like any other coupling in the 98 mm accessory family. There's nothing to align or adjust.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat does it add to my optical train?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003e33.2 mm of light path, per Takahashi's published figure.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes it work with any Takahashi telescope?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eIt's built to the 98 mm thread standard shared by the CCA-250 camera angle system. Send us your setup and we'll confirm compatibility.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes it include any optics?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eNo. It's a mechanical adapter only.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eIn short: a 98 mm-thread spacer that adds 33.2 mm of light path to a CCA-250-based accessory train — purely mechanical, and built to slot into Takahashi's existing 98 mm system.\u003c\/p\u003e","brand":"Takahashi","offers":[{"title":"Default Title","offer_id":54047916589167,"sku":"TAK-TKA86205","price":160.16,"currency_code":"CAD","in_stock":false}],"url":"https:\/\/ontariotelescope.com\/products\/takahashi-98mm-rd-ext-33-2mm-adapter","provider":"Ontario Telescope and Accessories","version":"1.0","type":"link"}