{"product_id":"used-thousand-oaks-lp-2-narrowband-filter-1-25","title":"Used Thousand Oaks LP-2 Narrowband Filter, 1.25\"","description":"\u003ch4\u003eCondition:\u003c\/h4\u003e\n\u003cp\u003eThis is a Thousand Oaks LP-2 narrowband filter for 1.25\" eyepieces.  It is in good condition, with some spotting on both sides of the optical surfaces.  See the photos.  We have taken this condition issue into consideration in the pricing.  At less than HALF PRICE, this won't last! \u003c\/p\u003e\n\u003cp\u003eIt comes in its original jewel case. \u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003ch4\u003eDescription:\u003c\/h4\u003e\n\u003cdiv id=\"shopify-section-template--16198956580937__main\" class=\"shopify-section product--section section--canonical\"\u003e\n\u003csection class=\"product__container\n    product__container--two-columns\"\u003e\n\u003carticle class=\"product--outer\"\u003e\n\u003cdiv class=\"product-main\"\u003e\n\u003cdiv class=\"product-details\"\u003e\n\u003cdiv class=\"product-block\n            product-block--description\"\u003e\n\u003cdiv class=\"product-description rte\"\u003e\n\u003cp class=\"\"\u003e\u003cstrong\u003eHigh-Contrast Nebula Views, Even from the City\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp class=\"\"\u003eThe\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003eThousand Oaks LP-2\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eis a\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e1.25\" narrowband filter\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003edesigned for visual observers who want to cut through light pollution and see emission nebulae in greater detail—even from the suburbs or city. With a generous\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e280 Ångstrom passband\u003c\/strong\u003e, it transmits strongly at all three key nebular emission lines:\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003ehydrogen-beta at 4861Å\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eand\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003eoxygen-III at 4959Å and 5007Å\u003c\/strong\u003e, while sharply blocking unwanted light from streetlights, skyglow, and moonlight.\u003c\/p\u003e\n\u003cp class=\"\"\u003eThe result is a darker sky background and dramatically improved contrast on nebulae like the\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003eVeil\u003c\/strong\u003e,\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003eNorth American\u003c\/strong\u003e,\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003eHelix\u003c\/strong\u003e,\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003eRosette\u003c\/strong\u003e,\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003eDumbbell\u003c\/strong\u003e, and\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003eLagoon\u003c\/strong\u003e—even under less-than-ideal conditions. It also performs beautifully under dark skies, making faint nebulae easier to detect.\u003c\/p\u003e\n\u003cp class=\"\"\u003eUnlike conventional narrowband filters with soft transmission edges, the LP-2 features\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003every steep passband cutoff slopes\u003c\/strong\u003e, helping it deliver\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003eroughly twice the contrast\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eof a typical broadband filter. All coatings are\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003esafely sealed between two layers of optical glass\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003efor durability and easy cleaning, even if your lens cloth gets a little enthusiastic.\u003c\/p\u003e\n\u003chr class=\"\"\u003e\n\u003ch3 class=\"\"\u003e\u003cstrong\u003eKey Features:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli class=\"\"\u003e\n\u003cp class=\"\"\u003e\u003cstrong\u003e280Å Narrowband Passband:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eCovers the critical H-Beta and O-III emission lines at 4861Å, 4959Å, and 5007Å\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli class=\"\"\u003e\n\u003cp class=\"\"\u003e\u003cstrong\u003eExceptional Transmission:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003e95–96%+ at key nebular wavelengths for brighter, bolder detail\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli class=\"\"\u003e\n\u003cp class=\"\"\u003e\u003cstrong\u003eVery Steep Cutoff Slopes:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eSuppresses unwanted wavelengths with higher contrast than standard narrowband filters\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli class=\"\"\u003e\n\u003cp class=\"\"\u003e\u003cstrong\u003eVisual Use Only:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eNot intended for imaging or reflection nebulae\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli class=\"\"\u003e\n\u003cp class=\"\"\u003e\u003cstrong\u003e1.25\" Eyepiece Compatibility:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eFits all standard 1.25\" threaded eyepieces and filter wheels\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli class=\"\"\u003e\n\u003cp class=\"\"\u003e\u003cstrong\u003eDurable Coatings:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eAll coatings are sandwiched between glass for long life and easy cleaning\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli class=\"\"\u003e\n\u003cp class=\"\"\u003e\u003cstrong\u003eMade in the USA:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eQuality you can rely on from Thousand Oaks Optical\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr class=\"\"\u003e\n\u003ch3 class=\"\"\u003e\u003cstrong\u003eRecommended Use:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp class=\"\"\u003eIdeal for\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003emedium and large aperture telescopes\u003c\/strong\u003e, especially when paired with\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003emedium to long focal length 1.25\" eyepieces\u003c\/strong\u003e. Performs well in both\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003elight-polluted environments\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eand\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003edark-sky sites\u003c\/strong\u003e, revealing nebulae with improved contrast and visibility.\u003c\/p\u003e\n\u003chr class=\"\"\u003e\n\u003ch3 class=\"\"\u003e\u003cstrong\u003eNot for Imaging or Reflection Nebulae:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp class=\"\"\u003eThis filter is designed strictly for\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003evisual use\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eon\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003eemission nebulae\u003c\/strong\u003e. It will not enhance views of galaxies, star clusters, or reflection nebulae.\u003c\/p\u003e\n\u003chr class=\"\"\u003e\n\u003ch3 class=\"\"\u003e\u003cstrong\u003eHow to Choose the Right Eyepiece for Your Filter\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp class=\"\"\u003eNot sure which eyepiece will give you the best view with this filter? Here's a quick tip:\u003c\/p\u003e\n\u003cp class=\"\"\u003eThe brightness of a nebula (and how well a filter performs) depends on something called the\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003eexit pupil\u003c\/strong\u003e—the size of the light beam exiting your eyepiece and entering your eye. For most filters, certain exit pupil sizes give you better contrast and visibility depending on your\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003esky conditions\u003c\/strong\u003e.\u003c\/p\u003e\n\u003cp class=\"\"\u003eTo find the right eyepiece (your target eyepiece), just\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003eenter your telescope's focal ratio\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003e(like f\/5, f\/10, etc.) in the calculator box below. It will show you which eyepiece focal lengths work best under different skies:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli class=\"\"\u003e\n\u003cp class=\"\"\u003e\u003cstrong\u003eDark Sky, Large Nebulae\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003e→ Use a long focal length eyepiece for a\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003elarge exit pupil\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003e(6–7mm)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli class=\"\"\u003e\n\u003cp class=\"\"\u003e\u003cstrong\u003eCity or Suburban Skies\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003e→ Use a medium eyepiece for a\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003emoderate exit pupil\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003e(3–5mm)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli class=\"\"\u003e\n\u003cp class=\"\"\u003e\u003cstrong\u003eSmaller Nebulae or High Contrast Needs\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003e→ A shorter focal length eyepiece for a\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003esmaller exit pupil\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003e(2–3mm) may help\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"\"\u003e\u003cstrong\u003eLP-2 Tip:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eFor general-purpose nebula viewing under light-polluted skies, a\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e3–5mm exit pupil\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eoffers the best balance of brightness and contrast. Under dark skies, stretch to\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e6–7mm\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003efor wide, immersive views of large emission structures.\u003c\/p\u003e\n\u003ch2\u003eTech Details: \u003c\/h2\u003e\n\u003ctable class=\"table\" id=\"product-attribute-specs-table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eMax City Exit Pupil\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e4mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eMax Dark Site Exit Pupil\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e6mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eMin City Exit Pupil\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e1mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eMin Dark Site Exit Pupil\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e2mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"manuals\"\u003e\u003cbr\u003e\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"product-block\n            product-block--complementary_products\"\u003e\n\u003cdiv class=\"complementary-products complementary-products--emphasized complementary-products--no-recommendations\"\u003e\u003cbr\u003e\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/article\u003e\n\u003c\/section\u003e\n\u003c\/div\u003e","brand":"Thousand Oaks","offers":[{"title":"Default Title","offer_id":49358313652483,"sku":"U2608-XXX-1000OAKS-LP-2","price":40.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1979\/5379\/files\/219e51f4-3928-4ee5-b857-b5ca01ca7d0d.jpg?v=1785614435","url":"https:\/\/milehighastro.com\/products\/used-thousand-oaks-lp-2-narrowband-filter-1-25","provider":"Mile High Astronomy","version":"1.0","type":"link"}