{"product_id":"optolong-l1-dual-combo-filter-set","title":"Optolong L1 Dual-Combo Filter Set – L-Quad Enhance + L-Para 2\"","description":"\u003cstyle\u003e\n  .opt-l1,\n  .opt-l1 * {\n    box-sizing: border-box;\n  }\n\n  .opt-l1 {\n    --ink: #171923;\n    --muted: #656978;\n    --line: #e3e5eb;\n    --soft: #f7f8fb;\n    --violet: #6657d9;\n    --blue: #246eb9;\n    --cyan: #2ba9b7;\n    --red: #d84e5b;\n    --orange: #d67637;\n\n    max-width: 1080px;\n    margin: 0 auto;\n    color: var(--ink);\n    font-family: inherit;\n    font-size: 16px;\n    line-height: 1.65;\n  }\n\n  .opt-l1 h2,\n  .opt-l1 h3 {\n    color: var(--ink) !important;\n  }\n\n  .opt-l1 h2 {\n    margin: 0 0 12px;\n    font-size: clamp(28px, 4vw, 42px);\n    line-height: 1.12;\n  }\n\n  .opt-l1 h3 {\n    margin: 0 0 10px;\n    font-size: 22px;\n    line-height: 1.25;\n  }\n\n  .opt-l1 p {\n    margin: 0 0 16px;\n  }\n\n  \/* HERO *\/\n\n  .opt-l1-hero {\n    position: relative;\n    overflow: hidden;\n    margin-bottom: 38px;\n    padding: clamp(34px, 7vw, 68px);\n    color: #fff;\n    background:\n      radial-gradient(circle at 85% 10%, rgba(112, 93, 255, .38), transparent 27%),\n      radial-gradient(circle at 70% 100%, rgba(31, 167, 181, .24), transparent 34%),\n      linear-gradient(125deg, #10111b 0%, #171735 52%, #20204b 100%);\n    border-radius: 18px;\n  }\n\n  .opt-l1-hero:after {\n    content: \"\";\n    position: absolute;\n    width: 260px;\n    height: 260px;\n    right: -75px;\n    bottom: -125px;\n    border: 34px solid rgba(255,255,255,.045);\n    border-radius: 50%;\n  }\n\n  .opt-l1-eyebrow {\n    display: inline-block;\n    margin-bottom: 15px;\n    padding: 6px 11px;\n    color: #ddd9ff;\n    background: rgba(255,255,255,.07);\n    border: 1px solid rgba(255,255,255,.16);\n    border-radius: 999px;\n    font-size: 11px;\n    font-weight: 800;\n    letter-spacing: .12em;\n    text-transform: uppercase;\n  }\n\n  .opt-l1-hero h2 {\n    max-width: 800px;\n    color: #fff !important;\n  }\n\n  .opt-l1-hero p {\n    position: relative;\n    z-index: 2;\n    max-width: 780px;\n    margin-bottom: 0;\n    color: #dcdeec;\n    font-size: 17px;\n  }\n\n  .opt-l1-hero strong {\n    color: #fff;\n  }\n\n  \/* QUICK FACTS *\/\n\n  .opt-l1-facts {\n    display: grid;\n    grid-template-columns: repeat(4, 1fr);\n    gap: 10px;\n    margin: -18px auto 42px;\n    width: 92%;\n    position: relative;\n    z-index: 3;\n  }\n\n  .opt-l1-fact {\n    padding: 15px 12px;\n    text-align: center;\n    background: #fff;\n    border: 1px solid var(--line);\n    border-radius: 10px;\n    box-shadow: 0 7px 24px rgba(30,32,48,.07);\n  }\n\n  .opt-l1-fact strong {\n    display: block;\n    margin-bottom: 1px;\n    font-size: 17px;\n  }\n\n  .opt-l1-fact span {\n    color: var(--muted);\n    font-size: 12px;\n  }\n\n  \/* TWO FILTER CARDS *\/\n\n  .opt-l1-section-title {\n    margin: 42px 0 18px;\n  }\n\n  .opt-l1-section-title p {\n    max-width: 760px;\n    color: var(--muted);\n  }\n\n  .opt-l1-filter-grid {\n    display: grid;\n    grid-template-columns: repeat(2, 1fr);\n    gap: 18px;\n  }\n\n  .opt-l1-filter {\n    overflow: hidden;\n    border: 1px solid var(--line);\n    border-radius: 14px;\n    background: #fff;\n  }\n\n  .opt-l1-filter-top {\n    padding: 26px 28px 22px;\n  }\n\n  .opt-l1-filter.quad .opt-l1-filter-top {\n    background:\n      linear-gradient(115deg, rgba(99,83,214,.09), rgba(43,169,183,.06));\n  }\n\n  .opt-l1-filter.para .opt-l1-filter-top {\n    background:\n      linear-gradient(115deg, rgba(43,169,183,.09), rgba(216,78,91,.07));\n  }\n\n  .opt-l1-filter-label {\n    margin-bottom: 5px;\n    color: var(--muted);\n    font-size: 11px;\n    font-weight: 800;\n    letter-spacing: .1em;\n    text-transform: uppercase;\n  }\n\n  .opt-l1-filter-name {\n    margin-bottom: 7px;\n    font-size: 25px;\n    font-weight: 800;\n    line-height: 1.15;\n  }\n\n  .opt-l1-filter-type {\n    color: var(--muted);\n    font-size: 14px;\n  }\n\n  .opt-l1-filter-body {\n    padding: 24px 28px 26px;\n  }\n\n  .opt-l1-filter-body ul {\n    margin: 0;\n    padding: 0;\n    list-style: none;\n  }\n\n  .opt-l1-filter-body li {\n    position: relative;\n    margin-bottom: 10px;\n    padding-left: 19px;\n  }\n\n  .opt-l1-filter-body li:last-child {\n    margin-bottom: 0;\n  }\n\n  .opt-l1-filter-body li:before {\n    content: \"\";\n    position: absolute;\n    top: .7em;\n    left: 0;\n    width: 6px;\n    height: 6px;\n    background: var(--violet);\n    border-radius: 50%;\n  }\n\n  .opt-l1-filter.para li:before {\n    background: var(--cyan);\n  }\n\n  \/* WAVELENGTH VISUAL *\/\n\n  .opt-l1-spectrum {\n    margin: 18px 0 0;\n    padding: 18px 20px;\n    background: #11131d;\n    border-radius: 10px;\n    color: #fff;\n  }\n\n  .opt-l1-spectrum-row {\n    display: grid;\n    grid-template-columns: 72px 1fr;\n    align-items: center;\n    gap: 12px;\n    margin-bottom: 11px;\n  }\n\n  .opt-l1-spectrum-row:last-child {\n    margin-bottom: 0;\n  }\n\n  .opt-l1-spectrum-label {\n    color: #c9ccda;\n    font-size: 12px;\n    font-weight: 700;\n  }\n\n  .opt-l1-spectrum-bar {\n    position: relative;\n    height: 9px;\n    overflow: hidden;\n    background: rgba(255,255,255,.07);\n    border-radius: 20px;\n  }\n\n  .opt-l1-spectrum-bar span {\n    position: absolute;\n    top: 0;\n    bottom: 0;\n    border-radius: 20px;\n  }\n\n  .opt-l1-spectrum-bar .hb {\n    left: 20%;\n    width: 7%;\n    background: #5267e8;\n  }\n\n  .opt-l1-spectrum-bar .oiii {\n    left: 30%;\n    width: 8%;\n    background: #33bfb0;\n  }\n\n  .opt-l1-spectrum-bar .ha {\n    left: 69%;\n    width: 8%;\n    background: #e54e57;\n  }\n\n  .opt-l1-spectrum-bar .sii {\n    left: 79%;\n    width: 8%;\n    background: #d66c3c;\n  }\n\n  .opt-l1-spectrum-bar.para .oiii {\n    left: 29%;\n    width: 6%;\n  }\n\n  .opt-l1-spectrum-bar.para .ha {\n    left: 69%;\n    width: 6%;\n  }\n\n  .opt-l1-spectrum-note {\n    margin-top: 10px !important;\n    color: #8e93a6;\n    font-size: 11px;\n  }\n\n  \/* SYNERGY *\/\n\n  .opt-l1-synergy {\n    display: grid;\n    grid-template-columns: 1fr auto 1fr;\n    align-items: center;\n    gap: 18px;\n    margin-top: 18px;\n    padding: 28px;\n    background: var(--soft);\n    border: 1px solid var(--line);\n    border-radius: 14px;\n  }\n\n  .opt-l1-synergy-card {\n    padding: 18px;\n    background: #fff;\n    border: 1px solid var(--line);\n    border-radius: 10px;\n  }\n\n  .opt-l1-synergy-card strong {\n    display: block;\n    margin-bottom: 4px;\n    font-size: 17px;\n  }\n\n  .opt-l1-synergy-card span {\n    color: var(--muted);\n    font-size: 14px;\n  }\n\n  .opt-l1-plus {\n    color: var(--violet);\n    font-size: 30px;\n    font-weight: 300;\n  }\n\n  \/* TARGET TABLE *\/\n\n  .opt-l1-table {\n    width: 100%;\n    margin-top: 18px;\n    border-collapse: separate;\n    border-spacing: 0;\n    overflow: hidden;\n    border: 1px solid var(--line);\n    border-radius: 12px;\n  }\n\n  .opt-l1-table th,\n  .opt-l1-table td {\n    padding: 13px 16px;\n    text-align: left;\n    border-bottom: 1px solid var(--line);\n  }\n\n  .opt-l1-table th {\n    background: #212331;\n    color: #fff;\n    font-size: 13px;\n  }\n\n  .opt-l1-table tr:last-child td {\n    border-bottom: 0;\n  }\n\n  .opt-l1-table tbody tr:nth-child(even) {\n    background: var(--soft);\n  }\n\n  .opt-l1-pill {\n    display: inline-block;\n    padding: 3px 8px;\n    border-radius: 999px;\n    background: #eceafe;\n    color: #5549bb;\n    font-size: 12px;\n    font-weight: 700;\n  }\n\n  .opt-l1-pill.para {\n    background: #e5f6f6;\n    color: #18767e;\n  }\n\n  .opt-l1-pill.both {\n    background: #f1edf8;\n    color: #654b80;\n  }\n\n  \/* SPECS *\/\n\n  .opt-l1-specs {\n    display: grid;\n    grid-template-columns: repeat(2, 1fr);\n    gap: 14px;\n    margin-top: 18px;\n  }\n\n  .opt-l1-spec {\n    padding: 20px;\n    border: 1px solid var(--line);\n    border-radius: 11px;\n  }\n\n  .opt-l1-spec strong {\n    display: block;\n    margin-bottom: 3px;\n  }\n\n  .opt-l1-spec span {\n    color: var(--muted);\n    font-size: 14px;\n  }\n\n  \/* INCLUDED *\/\n\n  .opt-l1-included {\n    margin-top: 18px;\n    padding: 25px 28px;\n    border-left: 4px solid var(--violet);\n    background: var(--soft);\n    border-radius: 8px;\n  }\n\n  .opt-l1-included ul {\n    margin: 8px 0 0;\n    padding-left: 20px;\n  }\n\n  \/* RESPONSIVE *\/\n\n  @media (max-width: 760px) {\n    .opt-l1-facts {\n      grid-template-columns: repeat(2, 1fr);\n    }\n\n    .opt-l1-filter-grid,\n    .opt-l1-specs {\n      grid-template-columns: 1fr;\n    }\n\n    .opt-l1-synergy {\n      grid-template-columns: 1fr;\n    }\n\n    .opt-l1-plus {\n      text-align: center;\n      line-height: 1;\n    }\n\n    .opt-l1-table th:nth-child(3),\n    .opt-l1-table td:nth-child(3) {\n      display: none;\n    }\n  }\n\u003c\/style\u003e\n\n\n\u003cdiv class=\"opt-l1\"\u003e\n\n  \u003c!-- HERO --\u003e\n  \u003csection class=\"opt-l1-hero\"\u003e\n    \u003cspan class=\"opt-l1-eyebrow\"\u003eOptolong L1 Dual-Combo Set\u003c\/span\u003e\n\n    \u003ch2\u003eTwo approaches to the deep sky.\u003c\/h2\u003e\n\n    \u003cp\u003e\n      The \u003cstrong\u003eOptolong L-Quad Enhance + L-Para Filter Set\u003c\/strong\u003e\n      pairs a versatile quad-band light-pollution filter with a\n      10nm Hα\/OIII dual-band filter, giving color-camera astrophotographers\n      a practical way to move between broadband deep-sky imaging and\n      high-contrast emission-nebula imaging.\n    \u003c\/p\u003e\n  \u003c\/section\u003e\n\n\n  \u003c!-- QUICK FACTS --\u003e\n  \u003cdiv class=\"opt-l1-facts\"\u003e\n    \u003cdiv class=\"opt-l1-fact\"\u003e\n      \u003cstrong\u003e2 Filters\u003c\/strong\u003e\n      \u003cspan\u003eBroadband + Narrowband\u003c\/span\u003e\n    \u003c\/div\u003e\n\n    \u003cdiv class=\"opt-l1-fact\"\u003e\n      \u003cstrong\u003e2\"\u003c\/strong\u003e\n      \u003cspan\u003eMounted Filters\u003c\/span\u003e\n    \u003c\/div\u003e\n\n    \u003cdiv class=\"opt-l1-fact\"\u003e\n      \u003cstrong\u003e10nm + 10nm\u003c\/strong\u003e\n      \u003cspan\u003eL-Para Hα \/ OIII\u003c\/span\u003e\n    \u003c\/div\u003e\n\n    \u003cdiv class=\"opt-l1-fact\"\u003e\n      \u003cstrong\u003ef\/2+\u003c\/strong\u003e\n      \u003cspan\u003eL-Para Fast-Optics Ready\u003c\/span\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\n\n\n  \u003c!-- INTRO --\u003e\n  \u003cdiv class=\"opt-l1-section-title\"\u003e\n    \u003ch3\u003eWhy put these two filters together?\u003c\/h3\u003e\n\n    \u003cp\u003e\n      Because they solve different problems. The L-Quad Enhance preserves\n      substantially more broadband color information for objects such as\n      galaxies, star clusters, and reflection or mixed nebulae. The L-Para\n      takes the opposite approach, isolating Hα and OIII emission to pull\n      nebular structure away from the surrounding sky background.\n    \u003c\/p\u003e\n\n    \u003cp\u003e\n      Use either filter on its own, or capture data through both and combine\n      the broadband color of the L-Quad with the narrowband structure of the\n      L-Para during processing.\n    \u003c\/p\u003e\n  \u003c\/div\u003e\n\n\n  \u003c!-- FILTER COMPARISON --\u003e\n  \u003cdiv class=\"opt-l1-filter-grid\"\u003e\n\n    \u003cdiv class=\"opt-l1-filter quad\"\u003e\n      \u003cdiv class=\"opt-l1-filter-top\"\u003e\n        \u003cdiv class=\"opt-l1-filter-label\"\u003eGeneral Deep-Sky Imaging\u003c\/div\u003e\n        \u003cdiv class=\"opt-l1-filter-name\"\u003eL-Quad Enhance\u003c\/div\u003e\n        \u003cdiv class=\"opt-l1-filter-type\"\u003e\n          Quad-band light-pollution suppression filter\n        \u003c\/div\u003e\n      \u003c\/div\u003e\n\n      \u003cdiv class=\"opt-l1-filter-body\"\u003e\n        \u003cul\u003e\n          \u003cli\u003eDesigned for color-camera astrophotography\u003c\/li\u003e\n          \u003cli\u003eUseful for galaxies, nebulae, star clusters, reflection nebulae, and wide-field imaging\u003c\/li\u003e\n          \u003cli\u003eMore than 90% transmission at Hβ, OIII, Hα, and SII emission lines\u003c\/li\u003e\n          \u003cli\u003eSuppresses common mercury and sodium light-pollution wavelengths\u003c\/li\u003e\n          \u003cli\u003eNear-IR cutoff extending to 1000nm helps control unwanted IR\u003c\/li\u003e\n          \u003cli\u003eDesigned to retain more natural broadband color balance than narrowband filters\u003c\/li\u003e\n        \u003c\/ul\u003e\n\n        \u003cdiv class=\"opt-l1-spectrum\"\u003e\n          \u003cdiv class=\"opt-l1-spectrum-row\"\u003e\n            \u003cdiv class=\"opt-l1-spectrum-label\"\u003eL-Quad\u003c\/div\u003e\n            \u003cdiv class=\"opt-l1-spectrum-bar\"\u003e\n              \u003cspan class=\"hb\"\u003e\u003c\/span\u003e\n              \u003cspan class=\"oiii\"\u003e\u003c\/span\u003e\n              \u003cspan class=\"ha\"\u003e\u003c\/span\u003e\n              \u003cspan class=\"sii\"\u003e\u003c\/span\u003e\n            \u003c\/div\u003e\n          \u003c\/div\u003e\n\n          \u003cp class=\"opt-l1-spectrum-note\"\u003e\n            Conceptual wavelength guide only — not a measured transmission curve.\n          \u003c\/p\u003e\n        \u003c\/div\u003e\n      \u003c\/div\u003e\n    \u003c\/div\u003e\n\n\n    \u003cdiv class=\"opt-l1-filter para\"\u003e\n      \u003cdiv class=\"opt-l1-filter-top\"\u003e\n        \u003cdiv class=\"opt-l1-filter-label\"\u003eEmission Nebula Imaging\u003c\/div\u003e\n        \u003cdiv class=\"opt-l1-filter-name\"\u003eL-Para\u003c\/div\u003e\n        \u003cdiv class=\"opt-l1-filter-type\"\u003e\n          Dual 10nm Hα + OIII narrowband filter\n        \u003c\/div\u003e\n      \u003c\/div\u003e\n\n      \u003cdiv class=\"opt-l1-filter-body\"\u003e\n        \u003cul\u003e\n          \u003cli\u003e10nm FWHM bandpass centered on OIII at 500.7nm\u003c\/li\u003e\n          \u003cli\u003e10nm FWHM bandpass centered on Hα at 656.3nm\u003c\/li\u003e\n          \u003cli\u003eMore than 85% transmission of Hα and OIII in optical systems f\/2 and slower\u003c\/li\u003e\n          \u003cli\u003eSuppresses mercury, sodium, LED, and other unwanted light-pollution wavelengths\u003c\/li\u003e\n          \u003cli\u003eOptimized for improved contrast and reduced halo behavior around bright stars\u003c\/li\u003e\n          \u003cli\u003eCompatible with conventional telescopes as well as fast systems including RASA and HyperStar\u003c\/li\u003e\n        \u003c\/ul\u003e\n\n        \u003cdiv class=\"opt-l1-spectrum\"\u003e\n          \u003cdiv class=\"opt-l1-spectrum-row\"\u003e\n            \u003cdiv class=\"opt-l1-spectrum-label\"\u003eL-Para\u003c\/div\u003e\n            \u003cdiv class=\"opt-l1-spectrum-bar para\"\u003e\n              \u003cspan class=\"oiii\"\u003e\u003c\/span\u003e\n              \u003cspan class=\"ha\"\u003e\u003c\/span\u003e\n            \u003c\/div\u003e\n          \u003c\/div\u003e\n\n          \u003cp class=\"opt-l1-spectrum-note\"\u003e\n            Conceptual wavelength guide only — not a measured transmission curve.\n          \u003c\/p\u003e\n        \u003c\/div\u003e\n      \u003c\/div\u003e\n    \u003c\/div\u003e\n\n  \u003c\/div\u003e\n\n\n  \u003c!-- SYNERGY --\u003e\n  \u003cdiv class=\"opt-l1-section-title\"\u003e\n    \u003ch3\u003eBroadband color + narrowband structure\u003c\/h3\u003e\n\n    \u003cp\u003e\n      The real advantage of the L1 Dual-Combo Set is that you don't necessarily\n      have to choose one filter or the other.\n    \u003c\/p\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"opt-l1-synergy\"\u003e\n\n    \u003cdiv class=\"opt-l1-synergy-card\"\u003e\n      \u003cstrong\u003eL-Quad Enhance\u003c\/strong\u003e\n      \u003cspan\u003e\n        Capture stars, continuum signal, broadband color, and the larger-scale\n        appearance of the target.\n      \u003c\/span\u003e\n    \u003c\/div\u003e\n\n    \u003cdiv class=\"opt-l1-plus\"\u003e+\u003c\/div\u003e\n\n    \u003cdiv class=\"opt-l1-synergy-card\"\u003e\n      \u003cstrong\u003eL-Para\u003c\/strong\u003e\n      \u003cspan\u003e\n        Capture concentrated Hα and OIII emission to reveal additional\n        nebulosity and fine structure.\n      \u003c\/span\u003e\n    \u003c\/div\u003e\n\n  \u003c\/div\u003e\n\n\n  \u003c!-- TARGET GUIDE --\u003e\n  \u003cdiv class=\"opt-l1-section-title\"\u003e\n    \u003ch3\u003eWhich filter should I use?\u003c\/h3\u003e\n\n    \u003cp\u003e\n      A simple starting point for choosing between the two filters.\n    \u003c\/p\u003e\n  \u003c\/div\u003e\n\n  \u003ctable class=\"opt-l1-table\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth\u003eTarget\u003c\/th\u003e\n        \u003cth\u003eStart With\u003c\/th\u003e\n        \u003cth\u003eWhy\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eGalaxies\u003c\/td\u003e\n        \u003ctd\u003e\u003cspan class=\"opt-l1-pill\"\u003eL-Quad\u003c\/span\u003e\u003c\/td\u003e\n        \u003ctd\u003ePreserves broadband RGB and continuum signal\u003c\/td\u003e\n      \u003c\/tr\u003e\n\n      \u003ctr\u003e\n        \u003ctd\u003eStar Clusters\u003c\/td\u003e\n        \u003ctd\u003e\u003cspan class=\"opt-l1-pill\"\u003eL-Quad\u003c\/span\u003e\u003c\/td\u003e\n        \u003ctd\u003eBetter suited to broadband stellar color\u003c\/td\u003e\n      \u003c\/tr\u003e\n\n      \u003ctr\u003e\n        \u003ctd\u003eReflection Nebulae\u003c\/td\u003e\n        \u003ctd\u003e\u003cspan class=\"opt-l1-pill\"\u003eL-Quad\u003c\/span\u003e\u003c\/td\u003e\n        \u003ctd\u003eReflection nebulae are broadband targets\u003c\/td\u003e\n      \u003c\/tr\u003e\n\n      \u003ctr\u003e\n        \u003ctd\u003eEmission Nebulae\u003c\/td\u003e\n        \u003ctd\u003e\u003cspan class=\"opt-l1-pill para\"\u003eL-Para\u003c\/span\u003e\u003c\/td\u003e\n        \u003ctd\u003eIsolates Hα and OIII emission\u003c\/td\u003e\n      \u003c\/tr\u003e\n\n      \u003ctr\u003e\n        \u003ctd\u003eBright HII Regions\u003c\/td\u003e\n        \u003ctd\u003e\u003cspan class=\"opt-l1-pill para\"\u003eL-Para\u003c\/span\u003e\u003c\/td\u003e\n        \u003ctd\u003eHigher contrast for ionized gas structures\u003c\/td\u003e\n      \u003c\/tr\u003e\n\n      \u003ctr\u003e\n        \u003ctd\u003eMixed Broadband + Emission Targets\u003c\/td\u003e\n        \u003ctd\u003e\u003cspan class=\"opt-l1-pill both\"\u003eUse Both\u003c\/span\u003e\u003c\/td\u003e\n        \u003ctd\u003eCombine natural broadband color with narrowband detail\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\n\n  \u003c!-- FAST OPTICS --\u003e\n  \u003cdiv class=\"opt-l1-section-title\"\u003e\n    \u003ch3\u003eMade for modern color-camera imaging\u003c\/h3\u003e\n\n    \u003cp\u003e\n      The L-Para is particularly useful for astrophotographers working with\n      fast optical systems. Optolong specifies high Hα and OIII transmission\n      for systems from \u003cstrong\u003ef\/2 and slower\u003c\/strong\u003e and specifically lists\n      fast configurations such as \u003cstrong\u003eRASA and HyperStar\u003c\/strong\u003e.\n    \u003c\/p\u003e\n\n    \u003cp\u003e\n      That makes the combination especially versatile for imagers who use one\n      camera across multiple telescopes or regularly move between conventional\n      refractors and faster astrographs.\n    \u003c\/p\u003e\n  \u003c\/div\u003e\n\n\n  \u003c!-- SPECS --\u003e\n  \u003cdiv class=\"opt-l1-section-title\"\u003e\n    \u003ch3\u003eKey specifications\u003c\/h3\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"opt-l1-specs\"\u003e\n\n    \u003cdiv class=\"opt-l1-spec\"\u003e\n      \u003cstrong\u003eFilter Format\u003c\/strong\u003e\n      \u003cspan\u003e2\" mounted filters\u003c\/span\u003e\n    \u003c\/div\u003e\n\n    \u003cdiv class=\"opt-l1-spec\"\u003e\n      \u003cstrong\u003eThread\u003c\/strong\u003e\n      \u003cspan\u003eM48 × 0.75\u003c\/span\u003e\n    \u003c\/div\u003e\n\n    \u003cdiv class=\"opt-l1-spec\"\u003e\n      \u003cstrong\u003eL-Quad Enhance\u003c\/strong\u003e\n      \u003cspan\u003eQuad-band light-pollution suppression filter\u003c\/span\u003e\n    \u003c\/div\u003e\n\n    \u003cdiv class=\"opt-l1-spec\"\u003e\n      \u003cstrong\u003eL-Para\u003c\/strong\u003e\n      \u003cspan\u003eDual 10nm Hα + OIII narrowband filter\u003c\/span\u003e\n    \u003c\/div\u003e\n\n    \u003cdiv class=\"opt-l1-spec\"\u003e\n      \u003cstrong\u003eL-Para OIII\u003c\/strong\u003e\n      \u003cspan\u003e500.7nm \/ 10nm FWHM\u003c\/span\u003e\n    \u003c\/div\u003e\n\n    \u003cdiv class=\"opt-l1-spec\"\u003e\n      \u003cstrong\u003eL-Para Hα\u003c\/strong\u003e\n      \u003cspan\u003e656.3nm \/ 10nm FWHM\u003c\/span\u003e\n    \u003c\/div\u003e\n\n    \u003cdiv class=\"opt-l1-spec\"\u003e\n      \u003cstrong\u003eL-Quad Transmission\u003c\/strong\u003e\n      \u003cspan\u003e\u0026gt;90% at Hβ \/ OIII \/ Hα \/ SII emission lines\u003c\/span\u003e\n    \u003c\/div\u003e\n\n    \u003cdiv class=\"opt-l1-spec\"\u003e\n      \u003cstrong\u003eL-Para Transmission\u003c\/strong\u003e\n      \u003cspan\u003e\u0026gt;85% at Hα \/ OIII in systems f\/2 and slower\u003c\/span\u003e\n    \u003c\/div\u003e\n\n  \u003c\/div\u003e\n\n\n  \u003c!-- COATINGS --\u003e\n  \u003cdiv class=\"opt-l1-section-title\"\u003e\n    \u003ch3\u003eOptolong coating technology\u003c\/h3\u003e\n\n    \u003cp\u003e\n      Both filters use multi-layer anti-reflection coatings and Optolong's\n      ion-assisted deposition process. The coating system is designed for\n      durability, scratch resistance, wavelength stability, and consistent\n      transmission across the optical surface.\n    \u003c\/p\u003e\n  \u003c\/div\u003e\n\n\n  \u003c!-- INCLUDED --\u003e\n  \u003cdiv class=\"opt-l1-included\"\u003e\n    \u003ch3\u003eWhat's Included\u003c\/h3\u003e\n\n    \u003cul\u003e\n      \u003cli\u003e1 × Optolong L-Quad Enhance 2\" Filter\u003c\/li\u003e\n      \u003cli\u003e1 × Optolong L-Para 2\" Filter\u003c\/li\u003e\n      \u003cli\u003eProtective filter case \/ packaging\u003c\/li\u003e\n    \u003c\/ul\u003e\n  \u003c\/div\u003e\n\n\u003c\/div\u003e","brand":"Optolong","offers":[{"title":"Default Title","offer_id":50307392471297,"sku":null,"price":399.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0327\/2569\/6648\/files\/29bb36448d29d877850fb5e0a683c570.jpg?v=1789079553","url":"https:\/\/starizona.com\/products\/optolong-l1-dual-combo-filter-set","provider":"Starizona","version":"1.0","type":"link"}