{"product_id":"optolong-l-ultimate-2-inch-3nm-dual-band-filter","title":"Optolong L-Ultimate 2\" 3nm Dual-Band Light Pollution Filter","description":"\u003c!--\nSHOPIFY PRODUCT TITLE:\nOptolong L-Ultimate 2\" 3nm Dual-Band Light Pollution Filter\n--\u003e\n\n\u003cstyle\u003e\n  .olu-page,\n  .olu-page * {\n    box-sizing: border-box;\n  }\n\n  .olu-page {\n    --olu-text: #202735;\n    --olu-muted: #5f6877;\n    --olu-line: #dce1e8;\n    --olu-soft: #f5f7fa;\n    --olu-accent: #287aa7;\n    --olu-dark: #101722;\n    max-width: 1120px;\n    margin: 0 auto;\n    color: var(--olu-text);\n    font-family: inherit;\n    line-height: 1.65;\n  }\n\n  .olu-page h2 {\n    margin: 42px 0 14px;\n    color: var(--olu-text);\n    font-size: clamp(24px, 3vw, 32px);\n    line-height: 1.2;\n  }\n\n  .olu-page h3 {\n    color: inherit;\n  }\n\n  .olu-page p {\n    margin: 0 0 16px;\n  }\n\n  .olu-intro {\n    margin-bottom: 28px;\n    font-size: 16px;\n  }\n\n  .olu-intro-lead {\n    font-size: 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border-collapse: collapse;\n  }\n\n  .olu-table th,\n  .olu-table td {\n    padding: 12px 14px;\n    text-align: left;\n    vertical-align: top;\n    border-bottom: 1px solid var(--olu-line);\n  }\n\n  .olu-table th {\n    background: var(--olu-soft);\n    font-weight: 700;\n  }\n\n  .olu-table tr:last-child td {\n    border-bottom: 0;\n  }\n\n  .olu-spec-table td:first-child {\n    width: 34%;\n    font-weight: 700;\n  }\n\n  .olu-faq details {\n    margin-bottom: 10px;\n    padding: 14px 16px;\n    background: var(--olu-soft);\n    border: 1px solid var(--olu-line);\n    border-radius: 9px;\n  }\n\n  .olu-faq summary {\n    cursor: pointer;\n    font-weight: 700;\n  }\n\n  .olu-faq details p {\n    margin: 10px 0 0;\n    color: var(--olu-muted);\n  }\n\n  .olu-warning {\n    margin-top: 24px;\n    padding: 16px 18px;\n    background: #fff8e8;\n    border: 1px solid #ead6a3;\n    border-radius: 8px;\n    font-size: 14px;\n  }\n\n  @media (max-width: 700px) {\n    .olu-feature-grid,\n    .olu-target-grid,\n    .olu-capture-grid {\n      grid-template-columns: 1fr;\n    }\n\n    .olu-stage {\n      border-radius: 12px;\n    }\n\n    .olu-arrow {\n      width: 38px;\n      height: 38px;\n      font-size: 21px;\n    }\n\n    .olu-prev {\n      left: 9px;\n    }\n\n    .olu-next {\n      right: 9px;\n    }\n\n    .olu-thumbs {\n      grid-template-columns: repeat(7, 82px);\n    }\n\n    .olu-spec-table td:first-child {\n      width: 42%;\n    }\n  }\n\u003c\/style\u003e\n\n\u003csection class=\"olu-page\"\u003e\n\n  \u003c!-- INTRODUCTION --\u003e\n\n  \u003cdiv class=\"olu-intro\"\u003e\n    \u003cp class=\"olu-intro-lead\"\u003e\u003cstrong\u003eThe Optolong L-Ultimate 2\" filter is a precision 3nm dual-narrowband light-pollution imaging filter designed for high-contrast emission-nebula astrophotography.\u003c\/strong\u003e\u003c\/p\u003e\n\n    \u003cp\u003eIts two ultra-narrow 3nm bandpasses isolate H-Alpha at 656.3nm and OIII at 500.7nm while rejecting mercury-vapor and sodium-vapor lighting, natural skyglow, and other unwanted wavelengths. Designed primarily for one-shot-color cameras—and compatible with DSLR, color or monochrome CMOS, and CCD cameras—the L-Ultimate delivers exceptional contrast and signal-to-noise performance under light-polluted skies.\u003c\/p\u003e\n\n    \u003cp\u003eThe result is a dramatically darker sky background, reduced star prominence, and enhanced detail in faint emission nebulae. Compared with broader dual-band filters, the L-Ultimate’s narrow 3nm passbands provide stronger light-pollution suppression and better separation between nebulosity and the surrounding sky. Its multilayer coatings are also optimized to minimize halos and reflections around bright stars.\u003c\/p\u003e\n  \u003c\/div\u003e\n\n  \u003c!-- KEY FEATURES --\u003e\n\n  \u003ch2\u003eOptolong L-Ultimate Features\u003c\/h2\u003e\n\n  \u003cdiv class=\"olu-feature-grid\"\u003e\n    \u003cdiv class=\"olu-feature\"\u003e\n      \u003ch3\u003eDual 3nm Bandpasses\u003c\/h3\u003e\n      \u003cp\u003eIsolates H-Alpha and OIII with an ultra-narrow 3nm bandwidth at each emission line.\u003c\/p\u003e\n    \u003c\/div\u003e\n\n    \u003cdiv class=\"olu-feature\"\u003e\n      \u003ch3\u003eStrong Light-Pollution Suppression\u003c\/h3\u003e\n      \u003cp\u003eRejects artificial lighting, broadband skyglow, and most wavelengths outside the two targeted emission bands.\u003c\/p\u003e\n    \u003c\/div\u003e\n\n    \u003cdiv class=\"olu-feature\"\u003e\n      \u003ch3\u003eOptimized for Color Cameras\u003c\/h3\u003e\n      \u003cp\u003eCaptures H-Alpha and OIII simultaneously with DSLR, mirrorless, and one-shot-color astronomy cameras.\u003c\/p\u003e\n    \u003c\/div\u003e\n\n    \u003cdiv class=\"olu-feature\"\u003e\n      \u003ch3\u003eHigher Nebula Contrast\u003c\/h3\u003e\n      \u003cp\u003eProduces darker backgrounds and stronger separation between faint nebulosity and the surrounding sky.\u003c\/p\u003e\n    \u003c\/div\u003e\n\n    \u003cdiv class=\"olu-feature\"\u003e\n      \u003ch3\u003eImproved Star Control\u003c\/h3\u003e\n      \u003cp\u003eThe narrow transmission bands reduce broadband starlight and help emphasize faint nebular structure.\u003c\/p\u003e\n    \u003c\/div\u003e\n\n    \u003cdiv class=\"olu-feature\"\u003e\n      \u003ch3\u003eAdvanced Optical Coatings\u003c\/h3\u003e\n      \u003cp\u003eIon-assisted multilayer coatings provide durable performance and are optimized to reduce reflections and halos.\u003c\/p\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\n\n  \u003c!-- PERFORMANCE GALLERY --\u003e\n\n  \u003cdiv class=\"olu-gallery\" aria-label=\"Optolong L-Ultimate astrophotography gallery\"\u003e\n\n    \u003cdiv class=\"olu-gallery-heading\"\u003e\n      \u003ch2\u003eReal-World L-Ultimate Performance\u003c\/h2\u003e\n      \u003cp\u003eExplore emission-nebula images captured with the Optolong L-Ultimate and related Optolong dual-band filters. Select a thumbnail or use the arrows to browse the gallery.\u003c\/p\u003e\n    \u003c\/div\u003e\n\n    \u003cinput type=\"radio\" name=\"olu-gallery\" id=\"olu-1\" checked\u003e\n    \u003cinput type=\"radio\" name=\"olu-gallery\" id=\"olu-2\"\u003e\n    \u003cinput type=\"radio\" name=\"olu-gallery\" id=\"olu-3\"\u003e\n    \u003cinput type=\"radio\" name=\"olu-gallery\" id=\"olu-4\"\u003e\n    \u003cinput type=\"radio\" name=\"olu-gallery\" id=\"olu-5\"\u003e\n    \u003cinput type=\"radio\" name=\"olu-gallery\" id=\"olu-6\"\u003e\n    \u003cinput type=\"radio\" name=\"olu-gallery\" id=\"olu-7\"\u003e\n\n    \u003cdiv class=\"olu-stage\"\u003e\n\n      \u003c!-- SLIDE 1 --\u003e\n\n      \u003cfigure class=\"olu-slide olu-slide-1\"\u003e\n        \u003cdiv class=\"olu-image\"\u003e\n          \u003cimg src=\"https:\/\/www.optolong.com\/uploads\/images\/20220813\/8e82dcbd4356c2b25658ae4d38898da9.jpg\" alt=\"Flying Bat Nebula Sh2-129 and Squid Nebula Ou4\" width=\"1000\" height=\"683\" loading=\"lazy\"\u003e\n          \u003cspan class=\"olu-count\"\u003e01 \/ 07\u003c\/span\u003e\n          \u003clabel class=\"olu-arrow olu-prev\" for=\"olu-7\" aria-label=\"Previous image\"\u003e‹\u003c\/label\u003e\n          \u003clabel class=\"olu-arrow olu-next\" for=\"olu-2\" aria-label=\"Next image\"\u003e›\u003c\/label\u003e\n        \u003c\/div\u003e\n\n        \u003cfigcaption class=\"olu-caption\"\u003e\n          \u003ch3\u003eFlying Bat and Squid Nebulae\u003c\/h3\u003e\n          \u003cp\u003eOu4 is an exceptionally faint bipolar OIII structure located within the reddish H-Alpha emission of Sh2-129 in Cepheus. This two-year project combined 29 hours of integration using L-eXtreme data for Ou4 and L-Ultimate data for Sh2-129.\u003c\/p\u003e\n\n          \u003cspan class=\"olu-credit\"\u003eImage: Tommaso Massimo Stella · Italy\u003c\/span\u003e\n\n          \u003cdiv class=\"olu-capture\"\u003e\n            \u003cdiv class=\"olu-capture-title\"\u003eCapture Details\u003c\/div\u003e\n            \u003cdiv class=\"olu-capture-grid\"\u003e\n              \u003cspan\u003e\u003cstrong\u003eExposure:\u003c\/strong\u003e 258 × 300s Ou4 + 30 × 900s Sh2-129\u003c\/span\u003e\n              \u003cspan\u003e\u003cstrong\u003eTelescopes:\u003c\/strong\u003e TS PhotoLine 102 f\/5.6 + Takahashi FS-60CB f\/4.2\u003c\/span\u003e\n              \u003cspan\u003e\u003cstrong\u003eCameras:\u003c\/strong\u003e ZWO ASI294MC Pro + Omegon veTEC 571C\u003c\/span\u003e\n              \u003cspan\u003e\u003cstrong\u003eMount:\u003c\/strong\u003e Sky-Watcher AZ-EQ6 GT\u003c\/span\u003e\n              \u003cspan\u003e\u003cstrong\u003eFilters:\u003c\/strong\u003e Optolong L-eXtreme + L-Ultimate\u003c\/span\u003e\n              \u003cspan\u003e\u003cstrong\u003eProcessing:\u003c\/strong\u003e DeepSkyStacker, Photoshop CC and PixInsight\u003c\/span\u003e\n            \u003c\/div\u003e\n          \u003c\/div\u003e\n        \u003c\/figcaption\u003e\n      \u003c\/figure\u003e\n\n      \u003c!-- SLIDE 2 --\u003e\n\n      \u003cfigure class=\"olu-slide olu-slide-2\"\u003e\n        \u003cdiv class=\"olu-image\"\u003e\n          \u003cimg src=\"https:\/\/www.optolong.com\/uploads\/images\/20220813\/0a012c0ef16bddfb90595bf2502e3c51.jpg\" alt=\"Veil Nebula captured with an Optolong L-Ultimate filter\" width=\"1000\" height=\"665\" loading=\"lazy\"\u003e\n          \u003cspan class=\"olu-count\"\u003e02 \/ 07\u003c\/span\u003e\n          \u003clabel class=\"olu-arrow olu-prev\" for=\"olu-1\" aria-label=\"Previous image\"\u003e‹\u003c\/label\u003e\n          \u003clabel class=\"olu-arrow olu-next\" for=\"olu-3\" aria-label=\"Next image\"\u003e›\u003c\/label\u003e\n        \u003c\/div\u003e\n\n        \u003cfigcaption class=\"olu-caption\"\u003e\n          \u003ch3\u003eVeil Nebula\u003c\/h3\u003e\n          \u003cp\u003eA 52-minute integration revealing the intricate emission filaments of this expansive supernova remnant.\u003c\/p\u003e\n\n          \u003cspan class=\"olu-credit\"\u003eImage: Tommy Lim KW · Malaysia\u003c\/span\u003e\n\n          \u003cdiv class=\"olu-capture\"\u003e\n            \u003cdiv class=\"olu-capture-title\"\u003eCapture Details\u003c\/div\u003e\n            \u003cdiv class=\"olu-capture-grid\"\u003e\n              \u003cspan\u003e\u003cstrong\u003eCamera:\u003c\/strong\u003e QHY168C\u003c\/span\u003e\n              \u003cspan\u003e\u003cstrong\u003eTelescope:\u003c\/strong\u003e Pentax 100 SDUF II f\/4\u003c\/span\u003e\n              \u003cspan\u003e\u003cstrong\u003eMount:\u003c\/strong\u003e Sky-Watcher AZ-EQ5 GT\u003c\/span\u003e\n              \u003cspan\u003e\u003cstrong\u003eFilter:\u003c\/strong\u003e Optolong 3nm L-Ultimate\u003c\/span\u003e\n              \u003cspan\u003e\u003cstrong\u003eExposure:\u003c\/strong\u003e 13 × 240s\u003c\/span\u003e\n            \u003c\/div\u003e\n          \u003c\/div\u003e\n        \u003c\/figcaption\u003e\n      \u003c\/figure\u003e\n\n      \u003c!-- SLIDE 3 --\u003e\n\n      \u003cfigure class=\"olu-slide olu-slide-3\"\u003e\n        \u003cdiv class=\"olu-image\"\u003e\n          \u003cimg src=\"https:\/\/www.optolong.com\/uploads\/images\/20220813\/31ceb16a19983c46396af72fe7ba3cc1.jpg\" alt=\"Sh2-132 Lion Nebula captured with an Optolong L-Ultimate filter\" width=\"1000\" height=\"668\" loading=\"lazy\"\u003e\n          \u003cspan class=\"olu-count\"\u003e03 \/ 07\u003c\/span\u003e\n          \u003clabel class=\"olu-arrow olu-prev\" for=\"olu-2\" aria-label=\"Previous image\"\u003e‹\u003c\/label\u003e\n          \u003clabel class=\"olu-arrow olu-next\" for=\"olu-4\" aria-label=\"Next image\"\u003e›\u003c\/label\u003e\n        \u003c\/div\u003e\n\n        \u003cfigcaption class=\"olu-caption\"\u003e\n          \u003ch3\u003eSh2-132 · The Lion Nebula\u003c\/h3\u003e\n          \u003cp\u003eAn eight-hour L-Ultimate dataset captured without dark or flat calibration frames.\u003c\/p\u003e\n\n          \u003cspan class=\"olu-credit\"\u003eImage: Andrea Maggi\u003c\/span\u003e\n\n          \u003cdiv class=\"olu-capture\"\u003e\n            \u003cdiv class=\"olu-capture-title\"\u003eCapture Details\u003c\/div\u003e\n            \u003cdiv class=\"olu-capture-grid\"\u003e\n              \u003cspan\u003e\u003cstrong\u003eExposure:\u003c\/strong\u003e 96 × 300s\u003c\/span\u003e\n              \u003cspan\u003e\u003cstrong\u003eCalibration:\u003c\/strong\u003e No darks or flats\u003c\/span\u003e\n              \u003cspan\u003e\u003cstrong\u003eFilter:\u003c\/strong\u003e Optolong L-Ultimate\u003c\/span\u003e\n            \u003c\/div\u003e\n          \u003c\/div\u003e\n        \u003c\/figcaption\u003e\n      \u003c\/figure\u003e\n\n      \u003c!-- SLIDE 4 --\u003e\n\n      \u003cfigure class=\"olu-slide olu-slide-4\"\u003e\n        \u003cdiv class=\"olu-image\"\u003e\n          \u003cimg src=\"https:\/\/www.optolong.com\/uploads\/images\/20220813\/4672efc207e69c658cf26c68e7bea6a4.jpg\" alt=\"Supernova remnant W63 captured with an Optolong L-Ultimate filter\" width=\"1000\" height=\"672\" loading=\"lazy\"\u003e\n          \u003cspan class=\"olu-count\"\u003e04 \/ 07\u003c\/span\u003e\n          \u003clabel class=\"olu-arrow olu-prev\" for=\"olu-3\" aria-label=\"Previous image\"\u003e‹\u003c\/label\u003e\n          \u003clabel class=\"olu-arrow olu-next\" for=\"olu-5\" aria-label=\"Next image\"\u003e›\u003c\/label\u003e\n        \u003c\/div\u003e\n\n        \u003cfigcaption class=\"olu-caption\"\u003e\n          \u003ch3\u003eSupernova Remnant W63\u003c\/h3\u003e\n          \u003cp\u003eA faint cosmic smoke ring along the Milky Way in Cygnus, surrounded by a rich complex of interstellar clouds and dust.\u003c\/p\u003e\n\n          \u003cspan class=\"olu-credit\"\u003eImage: José Jiménez · Spain\u003c\/span\u003e\n\n          \u003cdiv class=\"olu-capture\"\u003e\n            \u003cdiv class=\"olu-capture-title\"\u003eCapture Details\u003c\/div\u003e\n            \u003cdiv class=\"olu-capture-grid\"\u003e\n              \u003cspan\u003e\u003cstrong\u003eCamera:\u003c\/strong\u003e CentralDS-modified Canon EOS Mark IV\u003c\/span\u003e\n              \u003cspan\u003e\u003cstrong\u003eExposure:\u003c\/strong\u003e 20 × 900s at ISO 3200\u003c\/span\u003e\n              \u003cspan\u003e\u003cstrong\u003eMount:\u003c\/strong\u003e Sky-Watcher AZ-GTi\u003c\/span\u003e\n              \u003cspan\u003e\u003cstrong\u003eGuide camera:\u003c\/strong\u003e ZWO ASI120MM\u003c\/span\u003e\n              \u003cspan\u003e\u003cstrong\u003eFilter:\u003c\/strong\u003e Optolong L-Ultimate\u003c\/span\u003e\n            \u003c\/div\u003e\n          \u003c\/div\u003e\n        \u003c\/figcaption\u003e\n      \u003c\/figure\u003e\n\n      \u003c!-- SLIDE 5 --\u003e\n\n      \u003cfigure class=\"olu-slide olu-slide-5\"\u003e\n        \u003cdiv class=\"olu-image\"\u003e\n          \u003cimg src=\"https:\/\/www.optolong.com\/uploads\/images\/20220813\/f94ddb185f8fe14b6659bda59bfa14f0.jpg\" alt=\"Sharpless 129 captured with an Optolong L-Ultimate filter\" width=\"1000\" height=\"655\" loading=\"lazy\"\u003e\n          \u003cspan class=\"olu-count\"\u003e05 \/ 07\u003c\/span\u003e\n          \u003clabel class=\"olu-arrow olu-prev\" for=\"olu-4\" aria-label=\"Previous image\"\u003e‹\u003c\/label\u003e\n          \u003clabel class=\"olu-arrow olu-next\" for=\"olu-6\" aria-label=\"Next image\"\u003e›\u003c\/label\u003e\n        \u003c\/div\u003e\n\n        \u003cfigcaption class=\"olu-caption\"\u003e\n          \u003ch3\u003eSharpless 129\u003c\/h3\u003e\n          \u003cp\u003eThe Flying Bat Nebula rendered through a 7.5-hour L-Ultimate dataset.\u003c\/p\u003e\n\n          \u003cspan class=\"olu-credit\"\u003eImage: José Jiménez · Spain\u003c\/span\u003e\n\n          \u003cdiv class=\"olu-capture\"\u003e\n            \u003cdiv class=\"olu-capture-title\"\u003eCapture Details\u003c\/div\u003e\n            \u003cdiv class=\"olu-capture-grid\"\u003e\n              \u003cspan\u003e\u003cstrong\u003eCamera:\u003c\/strong\u003e CentralDS-modified Canon EOS Mark IV\u003c\/span\u003e\n              \u003cspan\u003e\u003cstrong\u003eExposure:\u003c\/strong\u003e 30 × 900s at ISO 3200\u003c\/span\u003e\n              \u003cspan\u003e\u003cstrong\u003eFilter:\u003c\/strong\u003e Optolong L-Ultimate\u003c\/span\u003e\n            \u003c\/div\u003e\n          \u003c\/div\u003e\n        \u003c\/figcaption\u003e\n      \u003c\/figure\u003e\n\n      \u003c!-- SLIDE 6 --\u003e\n\n      \u003cfigure class=\"olu-slide olu-slide-6\"\u003e\n        \u003cdiv class=\"olu-image\"\u003e\n          \u003cimg src=\"https:\/\/www.optolong.com\/uploads\/images\/20220813\/1d8c80c3e194a0161f9b4569df88ff1f.jpg\" alt=\"NGC 6888 Crescent Nebula HOO image\" width=\"1000\" height=\"667\" loading=\"lazy\"\u003e\n          \u003cspan class=\"olu-count\"\u003e06 \/ 07\u003c\/span\u003e\n          \u003clabel class=\"olu-arrow olu-prev\" for=\"olu-5\" aria-label=\"Previous image\"\u003e‹\u003c\/label\u003e\n          \u003clabel class=\"olu-arrow olu-next\" for=\"olu-7\" aria-label=\"Next image\"\u003e›\u003c\/label\u003e\n        \u003c\/div\u003e\n\n        \u003cfigcaption class=\"olu-caption\"\u003e\n          \u003ch3\u003eNGC 6888 · HOO Version\u003c\/h3\u003e\n          \u003cp\u003eThe Crescent Nebula presented in an HOO color palette from a narrowband imaging dataset.\u003c\/p\u003e\n\n          \u003cspan class=\"olu-credit\"\u003eImage: Andrea Maggi · Italy\u003c\/span\u003e\n\n          \u003cdiv class=\"olu-capture\"\u003e\n            \u003cdiv class=\"olu-capture-title\"\u003eCapture Details\u003c\/div\u003e\n            \u003cdiv class=\"olu-capture-grid\"\u003e\n              \u003cspan\u003e\u003cstrong\u003eTelescope:\u003c\/strong\u003e Askar 500\u003c\/span\u003e\n              \u003cspan\u003e\u003cstrong\u003eCamera:\u003c\/strong\u003e ZWO ASI6200\u003c\/span\u003e\n              \u003cspan\u003e\u003cstrong\u003eFilter:\u003c\/strong\u003e Optolong 3nm\u003c\/span\u003e\n              \u003cspan\u003e\u003cstrong\u003eSoftware:\u003c\/strong\u003e Voyager\u003c\/span\u003e\n            \u003c\/div\u003e\n          \u003c\/div\u003e\n        \u003c\/figcaption\u003e\n      \u003c\/figure\u003e\n\n      \u003c!-- SLIDE 7 --\u003e\n\n      \u003cfigure class=\"olu-slide olu-slide-7\"\u003e\n        \u003cdiv class=\"olu-image\"\u003e\n          \u003cimg src=\"https:\/\/www.optolong.com\/uploads\/images\/20220813\/a637b149e53e64b7d6e98dbf75f1c346.jpg\" alt=\"NGC 7635 Bubble Nebula and Sh2-157 captured with an L-Ultimate filter\" width=\"1000\" height=\"669\" loading=\"lazy\"\u003e\n          \u003cspan class=\"olu-count\"\u003e07 \/ 07\u003c\/span\u003e\n          \u003clabel class=\"olu-arrow olu-prev\" for=\"olu-6\" aria-label=\"Previous image\"\u003e‹\u003c\/label\u003e\n          \u003clabel class=\"olu-arrow olu-next\" for=\"olu-1\" aria-label=\"Next image\"\u003e›\u003c\/label\u003e\n        \u003c\/div\u003e\n\n        \u003cfigcaption class=\"olu-caption\"\u003e\n          \u003ch3\u003eNGC 7635 and Sh2-157\u003c\/h3\u003e\n          \u003cp\u003eTwo hours of integration on the Bubble Nebula and neighboring Sh2-157 from Saint-Barthélemy.\u003c\/p\u003e\n\n          \u003cspan class=\"olu-credit\"\u003eImage: Andrea Maggi · Italy\u003c\/span\u003e\n\n          \u003cdiv class=\"olu-capture\"\u003e\n            \u003cdiv class=\"olu-capture-title\"\u003eCapture Details\u003c\/div\u003e\n            \u003cdiv class=\"olu-capture-grid\"\u003e\n              \u003cspan\u003e\u003cstrong\u003eTelescope:\u003c\/strong\u003e Askar 80PH\u003c\/span\u003e\n              \u003cspan\u003e\u003cstrong\u003eCamera:\u003c\/strong\u003e ZWO ASI2600\u003c\/span\u003e\n              \u003cspan\u003e\u003cstrong\u003eFilter:\u003c\/strong\u003e Optolong L-Ultimate\u003c\/span\u003e\n              \u003cspan\u003e\u003cstrong\u003eIntegration:\u003c\/strong\u003e 2 hours\u003c\/span\u003e\n            \u003c\/div\u003e\n          \u003c\/div\u003e\n        \u003c\/figcaption\u003e\n      \u003c\/figure\u003e\n\n    \u003c\/div\u003e\n\n    \u003cnav class=\"olu-thumbs\" aria-label=\"Choose a gallery image\"\u003e\n      \u003clabel for=\"olu-1\" title=\"Flying Bat and Squid Nebulae\"\u003e\n        \u003cimg src=\"https:\/\/www.optolong.com\/uploads\/images\/20220813\/8e82dcbd4356c2b25658ae4d38898da9.jpg\" alt=\"\" loading=\"lazy\"\u003e\n      \u003c\/label\u003e\n\n      \u003clabel for=\"olu-2\" title=\"Veil Nebula\"\u003e\n        \u003cimg src=\"https:\/\/www.optolong.com\/uploads\/images\/20220813\/0a012c0ef16bddfb90595bf2502e3c51.jpg\" alt=\"\" loading=\"lazy\"\u003e\n      \u003c\/label\u003e\n\n      \u003clabel for=\"olu-3\" title=\"Lion Nebula\"\u003e\n        \u003cimg src=\"https:\/\/www.optolong.com\/uploads\/images\/20220813\/31ceb16a19983c46396af72fe7ba3cc1.jpg\" alt=\"\" loading=\"lazy\"\u003e\n      \u003c\/label\u003e\n\n      \u003clabel for=\"olu-4\" title=\"Supernova remnant W63\"\u003e\n        \u003cimg src=\"https:\/\/www.optolong.com\/uploads\/images\/20220813\/4672efc207e69c658cf26c68e7bea6a4.jpg\" alt=\"\" loading=\"lazy\"\u003e\n      \u003c\/label\u003e\n\n      \u003clabel for=\"olu-5\" title=\"Sharpless 129\"\u003e\n        \u003cimg src=\"https:\/\/www.optolong.com\/uploads\/images\/20220813\/f94ddb185f8fe14b6659bda59bfa14f0.jpg\" alt=\"\" loading=\"lazy\"\u003e\n      \u003c\/label\u003e\n\n      \u003clabel for=\"olu-6\" title=\"NGC 6888\"\u003e\n        \u003cimg src=\"https:\/\/www.optolong.com\/uploads\/images\/20220813\/1d8c80c3e194a0161f9b4569df88ff1f.jpg\" alt=\"\" loading=\"lazy\"\u003e\n      \u003c\/label\u003e\n\n      \u003clabel for=\"olu-7\" title=\"NGC 7635 and Sh2-157\"\u003e\n        \u003cimg src=\"https:\/\/www.optolong.com\/uploads\/images\/20220813\/a637b149e53e64b7d6e98dbf75f1c346.jpg\" alt=\"\" loading=\"lazy\"\u003e\n      \u003c\/label\u003e\n    \u003c\/nav\u003e\n\n  \u003c\/div\u003e\n\n  \u003c!-- SUITABLE TARGETS --\u003e\n\n  \u003ch2\u003eWhat Can You Photograph with the L-Ultimate?\u003c\/h2\u003e\n\n  \u003cdiv class=\"olu-target-grid\"\u003e\n    \u003cdiv class=\"olu-target-card\"\u003e\n      \u003ch3\u003eExcellent Targets\u003c\/h3\u003e\n      \u003cul\u003e\n        \u003cli\u003eEmission nebulae\u003c\/li\u003e\n        \u003cli\u003ePlanetary nebulae\u003c\/li\u003e\n        \u003cli\u003eSupernova remnants\u003c\/li\u003e\n        \u003cli\u003eWolf-Rayet nebulae\u003c\/li\u003e\n        \u003cli\u003eLarge, faint HII regions\u003c\/li\u003e\n      \u003c\/ul\u003e\n    \u003c\/div\u003e\n\n    \u003cdiv class=\"olu-target-card\"\u003e\n      \u003ch3\u003eNot Intended for Broadband Targets\u003c\/h3\u003e\n      \u003cul\u003e\n        \u003cli\u003eGalaxies and natural-color imaging\u003c\/li\u003e\n        \u003cli\u003eReflection nebulae\u003c\/li\u003e\n        \u003cli\u003eOpen and globular star clusters\u003c\/li\u003e\n        \u003cli\u003eTargets without meaningful H-Alpha or OIII emission\u003c\/li\u003e\n      \u003c\/ul\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\n\n  \u003c!-- COMPATIBILITY --\u003e\n\n  \u003cdiv class=\"olu-note\"\u003e\n    \u003cp\u003e\u003cstrong\u003eFocal-ratio compatibility:\u003c\/strong\u003e The standard L-Ultimate is best suited to optical systems around f\/4 and slower. Very fast systems—including many HyperStar and RASA configurations—can shift the narrow 3nm passbands and reduce transmission. For those systems, select a filter specifically optimized for fast focal ratios.\u003c\/p\u003e\n  \u003c\/div\u003e\n\n  \u003c!-- COMPARISON --\u003e\n\n  \u003ch2\u003eOptolong L-Ultimate vs. L-eXtreme\u003c\/h2\u003e\n\n  \u003cdiv class=\"olu-table-wrap\"\u003e\n    \u003ctable class=\"olu-table\"\u003e\n      \u003cthead\u003e\n        \u003ctr\u003e\n          \u003cth\u003eFeature\u003c\/th\u003e\n          \u003cth\u003eL-Ultimate\u003c\/th\u003e\n          \u003cth\u003eL-eXtreme\u003c\/th\u003e\n        \u003c\/tr\u003e\n      \u003c\/thead\u003e\n      \u003ctbody\u003e\n        \u003ctr\u003e\n          \u003ctd\u003e\u003cstrong\u003eH-Alpha bandpass\u003c\/strong\u003e\u003c\/td\u003e\n          \u003ctd\u003e3nm\u003c\/td\u003e\n          \u003ctd\u003e7nm\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr\u003e\n          \u003ctd\u003e\u003cstrong\u003eOIII bandpass\u003c\/strong\u003e\u003c\/td\u003e\n          \u003ctd\u003e3nm\u003c\/td\u003e\n          \u003ctd\u003e7nm\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr\u003e\n          \u003ctd\u003e\u003cstrong\u003eLight-pollution rejection\u003c\/strong\u003e\u003c\/td\u003e\n          \u003ctd\u003eMore aggressive\u003c\/td\u003e\n          \u003ctd\u003eHigh\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr\u003e\n          \u003ctd\u003e\u003cstrong\u003eSky background\u003c\/strong\u003e\u003c\/td\u003e\n          \u003ctd\u003eDarkest\u003c\/td\u003e\n          \u003ctd\u003eDark\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr\u003e\n          \u003ctd\u003e\u003cstrong\u003eBest suited for\u003c\/strong\u003e\u003c\/td\u003e\n          \u003ctd\u003eHeavy light pollution and maximum nebula contrast\u003c\/td\u003e\n          \u003ctd\u003eMore forgiving general dual-band imaging\u003c\/td\u003e\n        \u003c\/tr\u003e\n      \u003c\/tbody\u003e\n    \u003c\/table\u003e\n  \u003c\/div\u003e\n\n  \u003c!-- SPECIFICATIONS --\u003e\n\n  \u003ch2\u003eOptolong L-Ultimate Specifications\u003c\/h2\u003e\n\n  \u003cdiv class=\"olu-table-wrap\"\u003e\n    \u003ctable class=\"olu-table olu-spec-table\"\u003e\n      \u003ctbody\u003e\n        \u003ctr\u003e\n          \u003ctd\u003eFilter type\u003c\/td\u003e\n          \u003ctd\u003eDual-narrowband light-pollution imaging filter\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr\u003e\n          \u003ctd\u003eMounted size\u003c\/td\u003e\n          \u003ctd\u003e2\" \/ 50.8mm\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr\u003e\n          \u003ctd\u003eFilter thread\u003c\/td\u003e\n          \u003ctd\u003eStandard 2\" M48 filter thread\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr\u003e\n          \u003ctd\u003eH-Alpha transmission\u003c\/td\u003e\n          \u003ctd\u003e656.3nm with 3nm FWHM\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr\u003e\n          \u003ctd\u003eOIII transmission\u003c\/td\u003e\n          \u003ctd\u003e500.7nm with 3nm FWHM\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr\u003e\n          \u003ctd\u003eBlocking range\u003c\/td\u003e\n          \u003ctd\u003e300–1000nm\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr\u003e\n          \u003ctd\u003eOut-of-band blocking\u003c\/td\u003e\n          \u003ctd\u003eGreater than OD4\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr\u003e\n          \u003ctd\u003eSubstrate\u003c\/td\u003e\n          \u003ctd\u003eOptical glass\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr\u003e\n          \u003ctd\u003eOptical thickness\u003c\/td\u003e\n          \u003ctd\u003e1.85mm\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr\u003e\n          \u003ctd\u003eSurface quality\u003c\/td\u003e\n          \u003ctd\u003e60\/40\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr\u003e\n          \u003ctd\u003eTransmitted wavefront\u003c\/td\u003e\n          \u003ctd\u003eλ\/4 RMS\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr\u003e\n          \u003ctd\u003eParallelism\u003c\/td\u003e\n          \u003ctd\u003e30 arc seconds\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr\u003e\n          \u003ctd\u003eCoating\u003c\/td\u003e\n          \u003ctd\u003eMultilayer anti-reflection coating with ion-assisted deposition\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr\u003e\n          \u003ctd\u003eCamera compatibility\u003c\/td\u003e\n          \u003ctd\u003eDSLR, mirrorless, color or monochrome CMOS, and CCD cameras; primarily intended for OSC imaging\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr\u003e\n          \u003ctd\u003eRecommended focal ratio\u003c\/td\u003e\n          \u003ctd\u003eApproximately f\/4 and slower\u003c\/td\u003e\n        \u003c\/tr\u003e\n      \u003c\/tbody\u003e\n    \u003c\/table\u003e\n  \u003c\/div\u003e\n\n  \u003c!-- FAQ --\u003e\n\n  \u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\n  \u003cdiv class=\"olu-faq\"\u003e\n    \u003cdetails\u003e\n      \u003csummary\u003eWhat wavelengths does the Optolong L-Ultimate pass?\u003c\/summary\u003e\n      \u003cp\u003eThe filter passes two ultra-narrow 3nm bands centered on H-Alpha at 656.3nm and OIII at 500.7nm while blocking most other wavelengths.\u003c\/p\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eIs the L-Ultimate designed for one-shot-color cameras?\u003c\/summary\u003e\n      \u003cp\u003eYes. It is particularly effective with one-shot-color cameras because H-Alpha and OIII data can be recorded simultaneously in a single exposure.\u003c\/p\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eCan the L-Ultimate be used for galaxies?\u003c\/summary\u003e\n      \u003cp\u003eIt may reveal isolated H-Alpha regions within some galaxies, but it blocks most broadband light and is not intended for natural-color galaxy imaging.\u003c\/p\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eCan I use the L-Ultimate with HyperStar or RASA?\u003c\/summary\u003e\n      \u003cp\u003eThe standard L-Ultimate is not recommended for very fast optical systems. At fast focal ratios, bandpass shift can move the narrow transmission bands away from H-Alpha and OIII, reducing signal. A fast-optics-optimized filter is the better choice for most HyperStar and RASA systems.\u003c\/p\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eIs the L-Ultimate suitable for visual observing?\u003c\/summary\u003e\n      \u003cp\u003eThe L-Ultimate is designed primarily as an astrophotography filter. Its ultra-narrow 3nm passbands transmit very little light for conventional visual observing.\u003c\/p\u003e\n    \u003c\/details\u003e\n  \u003c\/div\u003e\n\n  \u003c!-- INCLUDED ITEMS --\u003e\n\n  \u003ch2\u003eWhat’s Included\u003c\/h2\u003e\n\n  \u003cul\u003e\n    \u003cli\u003eOptolong L-Ultimate 2\" mounted filter\u003c\/li\u003e\n    \u003cli\u003eProtective plastic storage case\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \n\n\u003c\/section\u003e","brand":"Optolong","offers":[{"title":"Default Title","offer_id":50172419571969,"sku":"OPT-LULT-2","price":419.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0327\/2569\/6648\/files\/l-ultimate-125-1.jpg?v=1786391028","url":"https:\/\/starizona.com\/products\/optolong-l-ultimate-2-inch-3nm-dual-band-filter","provider":"Starizona","version":"1.0","type":"link"}