{"product_id":"takahashi-2-mirror-diagonal-with-1-25-adapter","title":"Takahashi 2\" Mirror Diagonal with 1.25\" Adapter","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe 2″ Mirror Diagonal with 1.25″ Adapter is Takahashi's full-aperture visual diagonal, built to the same 1\/10-wave optical standard as the secondary mirrors in its Epsilon astrographs. It accepts a 2″ (50.8 mm) barrel on both the telescope and eyepiece sides, with a 106.5 mm light path, and ships with the \u003ca href=\"\/products\/takahashi-1-25-adapter-for-2-diagonal\"\u003e1.25″ Adapter\u003c\/a\u003e (TKA00111) included so you can run 1.25″ eyepieces through the same diagonal. The diagonal mirror alone weighs 460 g; with the adapter fitted, the complete kit is 505 g.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThis is a good match if you observe visually through a Takahashi refractor or Newtonian and want full 2″ aperture through the diagonal rather than the light loss of stepping down to 1.25″ early in the light path.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eFull 2″ (50.8 mm) clear aperture:\u003c\/strong\u003e passes the full cone of light from wide-field 2″ eyepieces without the vignetting a 1.25″ diagonal introduces.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1\/10-wave mirror figure:\u003c\/strong\u003e matched to the optical standard Takahashi uses on its own telescope secondaries.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFully blackened interior:\u003c\/strong\u003e controls internal reflections and stray light.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1.25″ Adapter included:\u003c\/strong\u003e steps the eyepiece side down to 31.75 mm when you want 1.25″ eyepieces or accessories, at no extra light path cost beyond the adapter's own 11 mm.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eOptical \/ Mechanical Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eA 90-degree mirror diagonal folds the visual light path for a comfortable viewing angle on a telescope pointed high. The mirror substrate carries a 1\/10-wave figure and Takahashi's mirror coating, and the housing accepts a 2″ (50.8 mm) barrel on the telescope side plus an M48 x 0.75 female thread, with a 2″ (50.8 mm) female barrel on the eyepiece side. Light path length through the diagonal is 106.5 mm — a figure to include when you're totaling backfocus for a visual train. See the \u003ca href=\"\/pages\/takahashi-back-focus-guide\"\u003eTakahashi Back Focus Guide\u003c\/a\u003e.\u003c\/p\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/TKA00543-schema.png?v=1786912644\" alt=\"Takahashi TKA00543 2 inch mirror diagonal with 1.25 inch adapter dimensional schematic\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eWide-field visual observing with 2″ eyepieces; general-purpose visual diagonal for any Takahashi refractor or Newtonian with a 2″ focuser; stepped down to 1.25″ with the included adapter for higher-power eyepieces or a Barlow.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eFits any 2″ (50.8 mm) focuser drawtube or visual back, either directly on the barrel or via the M48 x 0.75 thread. Not compatible with the classic FSQ-106, which uses a different focuser interface. Pairs with the \u003ca href=\"\/products\/takahashi-1-25-adapter-for-2-diagonal\"\u003e1.25″ Adapter\u003c\/a\u003e (included) for 1.25″ eyepieces and accessories; the adapter is also sold separately if you need a spare.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eGood to Know Before You Order\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eIt's a visual accessory, not an imaging one.\u003c\/strong\u003e There's no camera-side thread — it's built for eyepieces.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIt isn't compatible with the classic FSQ-106.\u003c\/strong\u003e Takahashi notes this directly; if you're not sure which FSQ generation you have, send us your telescope's serial number and we'll confirm the fit.\u003c\/p\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 drops into any 2″ focuser or visual back and locks with the same thumbscrews as any diagonal.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is it best used for?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eFull-aperture visual observing with 2″ eyepieces, and 1.25″ eyepieces once the included adapter is fitted.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes it work for astrophotography?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eIt's a visual diagonal — mirror diagonals fold the light path for eye observing rather than a straight-through imaging train.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat's included?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eThe 2″ mirror diagonal and the 1.25″ Adapter (TKA00111).\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eA full-aperture, 1\/10-wave 2″ mirror diagonal that ships with a 1.25″ adapter included, giving you both eyepiece sizes off a single 106.5 mm light path.\u003c\/p\u003e","brand":"Takahashi","offers":[{"title":"Default Title","offer_id":54047080644719,"sku":"TAK-TKA00543","price":713.57,"currency_code":"CAD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/tdm0200_2_2.jpg?v=1786913032","url":"https:\/\/ontariotelescope.com\/products\/takahashi-2-mirror-diagonal-with-1-25-adapter","provider":"Ontario Telescope and Accessories","version":"1.0","type":"link"}