{"product_id":"takahashi-tpl-18-plossl-eyepiece","title":"Takahashi TPL-18 Plossl Eyepiece","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe TPL-18 is an 18 mm Plossl eyepiece from Takahashi's TPL series, the line that replaced the company's earlier Abbe and LE eyepieces. It gives a 48° apparent field with 13 mm of eye relief, from four elements in two groups — the classic Plossl configuration, built here in high-refraction, low-dispersion glass that Takahashi states cuts center-field chromatic aberration to roughly half the level of the Abbe series.\u003c\/p\u003e\u003cp\u003eAt 18 mm it sits toward the lower-power end of the TPL range: enough magnification to resolve lunar detail and closer double stars, with a true field wide enough that a target does not need constant re-centering on an undriven mount.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThis is a good match if you want a general-purpose eyepiece for the Moon, planets, double stars and brighter deep-sky objects at moderate power, without paying for a wide-field design built for a use you may not need. The 48° field is the traditional Plossl width — narrower than a modern wide-field eyepiece, and correspondingly simpler and less expensive to produce well.\u003c\/p\u003e\u003cp\u003eIt is a visual eyepiece. Imaging trains connect a camera directly and do not use one.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e18 mm focal length:\u003c\/strong\u003e moderate power on most Takahashi refractors and reflectors — see Compatibility for real figures.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e48° apparent field:\u003c\/strong\u003e the traditional Plossl field width, sharp across the center with a mild softening toward the edge.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e13 mm eye relief:\u003c\/strong\u003e a comfortable eye position for direct viewing.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e4 elements in 2 groups:\u003c\/strong\u003e the symmetric Plossl configuration, unchanged in principle for decades because it works.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHigh-refraction, low-dispersion glass:\u003c\/strong\u003e tightens center-field chromatic correction relative to Takahashi's earlier Abbe and LE eyepieces.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMulti-coated optics:\u003c\/strong\u003e 99% visible-light transmission with a matte barrel finish to control stray light.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eOptical Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe Plossl design pairs two achromatic doublets symmetrically around the field stop — four elements in two groups. It is one of the oldest eyepiece formulas still in wide production, because the layout does the basic job well: a sharp, high-contrast image at a reasonable eye relief and manufacturing cost. Takahashi's TPL series updates the formula with higher-refraction, lower-dispersion glass than its own earlier Abbe and LE lines, which measurably tightens chromatic correction at the center of the field.\u003c\/p\u003e\u003cp\u003eTakahashi's own literature describes the TPL series as sharp from the center out to roughly the halfway point of the 48° field, with mild star distortion toward the corners — a known characteristic of the Plossl form rather than a manufacturing shortfall. Takahashi also states that pairing the TPL series with the 2x Ortho Barlow clearly improves flatfieldness, with the combination approaching full-field correction.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eLunar observing\u003c\/strong\u003e — crater walls, rilles and terminator relief at moderate power.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDouble star splitting\u003c\/strong\u003e where a moderate, well-corrected field is enough.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrighter deep-sky objects\u003c\/strong\u003e — open clusters, globular clusters and planetary nebulae.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGeneral-purpose visual observing\u003c\/strong\u003e across a range of telescope apertures and focal lengths.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePaired with the 2x Ortho Barlow\u003c\/strong\u003e for a flatter field at roughly double the power.\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\u003eMagnification:\u003c\/strong\u003e divide your telescope's focal length by 18. An FS-60CB at 355 mm gives about 20x; an FC-100DZ at 800 mm gives about 44x; a Mewlon 210 at 2415 mm gives about 134x.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBarrel:\u003c\/strong\u003e 31.7 mm — a standard 1.25-inch fit for Takahashi and most third-party diagonals and focusers.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDiagonal:\u003c\/strong\u003e in a refractor you will normally use it behind a star diagonal. The Takahashi 1.25-inch prism diagonal is a direct pairing.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e2x Ortho Barlow:\u003c\/strong\u003e Takahashi publishes that flatfieldness across the TPL series clearly improves when used through the 2x Ortho Barlow, at roughly double this eyepiece's magnification.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBack focus:\u003c\/strong\u003e for adapter and spacing questions across your imaging or visual train, see the \u003ca href=\"\/pages\/takahashi-back-focus-guide\"\u003eTakahashi Back Focus Guide\u003c\/a\u003e.\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\n\u003cstrong\u003e48° is a traditional field, not an ultra-wide one.\u003c\/strong\u003e An 82° or 100° eyepiece gives a more immersive view; the TPL trades that width for a simpler design that still delivers a sharp center field.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMagnification depends on your telescope.\u003c\/strong\u003e The same 18 mm gives about 20x on a short 60 mm refractor and 134x on a Mewlon 210 — send us your telescope model and we will confirm where it lands in your eyepiece set.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIt is a visual eyepiece.\u003c\/strong\u003e Camera trains connect directly to the telescope or its corrector.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e110 g is light\u003c\/strong\u003e — it will not register in most focuser-balance calculations.\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 drops into a 1.25-inch diagonal or focuser and you focus. Nothing to assemble or adjust.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat magnification will I get?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eYour telescope's focal length divided by 18. Send us your telescope model and we will work out where it fits alongside the eyepieces you already own.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow does it compare to Takahashi's older Abbe and LE eyepieces?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eThe TPL series uses higher-refraction, lower-dispersion glass, cutting center-field chromatic aberration to roughly half the Abbe level and about two-thirds of the LE level.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs it good for deep-sky observing?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eIt works well on brighter clusters and planetary nebulae at moderate power. For a wider true field at lower power from the same series, the TPL-50 is the long-focal-length option.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan I use it with glasses?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003e13 mm of eye relief is workable for some glasses wearers, depending on your frames.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWill it work with a Barlow?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eYes — the 2x Ortho Barlow doubles the magnification and, per Takahashi, improves the TPL series' flatfieldness at the same time.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs it parfocal with other Takahashi eyepieces?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eExpect to refocus when switching between eyepiece families.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eIn short: an 18 mm Plossl eyepiece with a 48° field and 13 mm of eye relief, built from four elements in two groups with glass chosen to keep the center field free of chromatic aberration. It suits general lunar, double-star and moderate-power deep-sky viewing, and flattens out further when paired with Takahashi's 2x Ortho Barlow.\u003c\/p\u003e","brand":"Takahashi","offers":[{"title":"Default Title","offer_id":54047075434607,"sku":"TAK-TKA00622","price":290.29,"currency_code":"CAD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/tka00622.jpg?v=1786912747","url":"https:\/\/ontariotelescope.com\/products\/takahashi-tpl-18-plossl-eyepiece","provider":"Ontario Telescope and Accessories","version":"1.0","type":"link"}