{"product_id":"takahashi-tpl-25-plossl-eyepiece","title":"Takahashi TPL-25 Plossl Eyepiece","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe TPL-25 is a 25 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 18 mm of eye relief, from four elements in two groups — the classic Plossl configuration, built 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 25 mm it sits toward the lower-power, wider-true-field end of the TPL range — a comfortable eyepiece for framing a broader area of sky rather than pushing magnification.\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, lower-power eyepiece for open clusters, star fields and wider lunar views, with a comfortable 18 mm of eye relief. The 48° field is the traditional Plossl width — narrower than a modern wide-field design, 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\u003e25 mm focal length:\u003c\/strong\u003e lower power and a wider true field on most Takahashi telescopes — 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 mild softening toward the edge.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e18 mm eye relief:\u003c\/strong\u003e comfortable eye position, including for many glasses wearers.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e4 elements in 2 groups:\u003c\/strong\u003e the symmetric Plossl configuration.\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, one of the longest-serving eyepiece formulas in production because it delivers a sharp, high-contrast image at reasonable cost. Takahashi's TPL series builds it in higher-refraction, lower-dispersion glass than the company's earlier Abbe and LE lines, which measurably tightens chromatic correction at the center of the field.\u003c\/p\u003e\u003cp\u003eTakahashi 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 — typical of the Plossl form at this field width. Takahashi states that pairing the 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\u003eOpen clusters and star fields\u003c\/strong\u003e at low-to-moderate power with a wide true field for the focal length.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLunar observing\u003c\/strong\u003e where a fuller view of the disc is wanted rather than crater-level detail.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDouble star sweeping\u003c\/strong\u003e and general low-power visual observing.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eA comfortable eyepiece for extended sessions,\u003c\/strong\u003e given the 18 mm eye relief.\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 25. An FS-60CB at 355 mm gives about 14x; an FC-100DZ at 800 mm gives about 32x; a Mewlon 210 at 2415 mm gives about 97x.\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 25 mm gives about 14x on a short 60 mm refractor and 97x 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\u003e140 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 25. 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\u003eYes — at 25 mm it gives one of the wider true fields in the TPL range, well suited to open clusters and star fields rather than high-power planetary detail.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan I use it with glasses?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003e18 mm of eye relief is comfortable for most glasses wearers.\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\u003eYou'll need to refocus when switching between eyepiece families.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eIn short: a 25 mm Plossl eyepiece with a 48° field and 18 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 low-power cluster and star-field viewing, and flattens out further when paired with Takahashi's 2x Ortho Barlow.\u003c\/p\u003e","brand":"Takahashi","offers":[{"title":"Default Title","offer_id":54047075565679,"sku":"TAK-TKA00623","price":317.46,"currency_code":"CAD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/tka00623.jpg?v=1786912784","url":"https:\/\/ontariotelescope.com\/products\/takahashi-tpl-25-plossl-eyepiece","provider":"Ontario Telescope and Accessories","version":"1.0","type":"link"}