{"product_id":"optolong-sho-3nm-narrowband-filter-kit-3-pcs","title":"Optolong Ha, OIII \u0026 SII 3nm Narrowband Filter Set","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eComplete SHO set includes H-alpha, OIII, and SII filters\u003c\/li\u003e\n\u003cli\u003eUltra-narrow 3nm bandpass for maximum contrast\u003c\/li\u003e\n\u003cli\u003eIsolates 656nm Ha and 500nm OIII emission lines\u003c\/li\u003e\n\u003cli\u003eAdvanced coatings for halo suppression and durability\u003c\/li\u003e\n\u003cli\u003eIdeal for imaging in heavily light-polluted or moonlit skies\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eOptolong Ha, OIII \u0026amp; SII 3nm Narrowband Filter Set\u003c\/h2\u003e\n\u003cp\u003eThe Optolong Ha, OIII \u0026amp; SII 3nm Narrowband Filter Set provides the essential tools for creating high-contrast Hubble Palette images from light-polluted locations. This three-filter kit isolates the most critical emission lines in deep-sky objects with an extremely narrow 3nm bandpass, targeting H-alpha at 656nm and OIII at 500nm. By aggressively rejecting skyglow, moonlight, and artificial light sources, this SHO set delivers a near-black sky background, making faint nebular structures visible with striking clarity.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003e3nm Bandpass: Isolate Emission Lines with Extreme Contrast\u003c\/h3\u003e\n\u003cp\u003eThe core of this filter set's power is its ultra-narrow 3nm full width at half maximum (FWHM). This level of precision allows only the light from specific ionized gases to reach your monochrome sensor, dramatically increasing the signal-to-noise ratio. The H-alpha filter captures the 656nm line characteristic of hydrogen, while the OIII filter isolates the dual 495.9nm and 500.7nm lines from doubly ionized oxygen, revealing the intricate structures within planetary nebulae and supernova remnants.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eAdvanced Coatings for Durability and Halo Suppression\u003c\/h3\u003e\n\u003cp\u003eOptolong utilizes an ion-assisted deposition coating process to ensure these filters are durable, scratch-resistant, and optically stable. This advanced manufacturing method maintains a consistent central wavelength that does not shift with temperature changes during an imaging session. Special attention has been paid to the OIII filter, which features an optimized coating design to significantly reduce the halos and internal reflections around bright stars that can compromise narrowband images.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eMastering the Hubble Palette: Building SHO Images\u003c\/h3\u003e\n\u003cp\u003eThis filter set is designed for creating false-color \"Hubble Palette\" images, where data from each filter is mapped to a specific color channel. By assigning the Sulphur-II (SII) data to red, Hydrogen-alpha (Ha) to green, and Oxygen-III (OIII) to blue (the SHO combination), you gain immense creative control over the final image. This technique is responsible for the iconic, high-impact astrophotography seen from the Hubble Space Telescope and allows you to highlight specific structures within a nebula based on its chemical composition.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003e3nm vs. 7nm Filters: Choosing the Right Bandwidth\u003c\/h3\u003e\n\u003cp\u003eWhile wider 7nm filters gather light more quickly, allowing for shorter individual exposures, they are more susceptible to light pollution and moonlight. The primary advantage of the Optolong 3nm filter set is its superior rejection of unwanted light, which is a decisive factor in urban or suburban skies.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eContrast:\u003c\/strong\u003e The 3nm bandpass delivers a significantly darker sky background and higher contrast on emission targets, making it the better choice for revealing the faintest details.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eExposure Time:\u003c\/strong\u003e The narrower bandpass requires longer total integration time to achieve the same signal level as a 7nm filter. However, the resulting data is often cleaner and requires less aggressive processing.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStar Control:\u003c\/strong\u003e The 3nm filters pass less continuum light from stars, resulting in smaller, tighter stars in the final image, which further enhances the visibility of the nebula itself.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the main advantage of the Optolong 3nm SHO filter set over wider filters?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe main advantage is \u003cstrong\u003econtrast\u003c\/strong\u003e. The ultra-narrow 3nm bandpass is extremely effective at blocking out light pollution, skyglow, and moonlight. This results in a much darker background and allows faint details in emission nebulae to stand out more clearly, which is especially critical for imaging from urban or suburban locations.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the Optolong 3nm SHO set perform under a full moon or in Bortle 8\/9 skies?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThis set excels in such conditions. Narrowband imaging is the preferred technique for challenging skies, and a 3nm bandpass is the most aggressive tool for the job. While a bright moon will still have some impact, these filters allow you to continue imaging targets like the North American Nebula (NGC 7000) even when broadband LRGB imaging would be impossible.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the Optolong 3nm filters with a color camera?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWhile designed for monochrome cameras, you can use them with a color camera, but it's inefficient. A color camera's Bayer matrix blocks roughly two-thirds of the incoming light for any given filter. For best results and to fully leverage the power of the 3nm bandpass, a \u003cstrong\u003emonochrome astronomy camera\u003c\/strong\u003e is strongly recommended.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhy is the OIII filter in the Optolong 3nm set specifically optimized for halo reduction?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eOIII filters are historically prone to producing halos or rings around very bright stars due to internal reflections within the filter glass. Optolong has applied its experience and advanced coating technologies to the 3nm OIII filter to minimize these artifacts, ensuring cleaner data, especially on targets within star-rich regions like the Cygnus constellation.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat kind of objects are best suited for imaging with the Optolong 3nm SHO set, like the Cygnus Loop (NGC 6960)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThis filter set is ideal for all types of emission nebulae. For a target like the Veil Nebula (Cygnus Loop), the results are spectacular. The \u003cstrong\u003eH-alpha\u003c\/strong\u003e filter will reveal the broad, rope-like hydrogen filaments, while the \u003cstrong\u003eOIII\u003c\/strong\u003e filter will isolate the delicate, blue-green shock fronts, which are extremely bright in oxygen. The SII provides additional structural detail for a full Hubble Palette composition.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow do I combine data from the Optolong Ha, OIII, and SII filters?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eIn post-processing software like PixInsight or Photoshop, you combine the three monochrome images into a single color image. The most common method is the \u003cstrong\u003eHubble Palette (SHO)\u003c\/strong\u003e:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eAssign the \u003cstrong\u003eSII\u003c\/strong\u003e image to the Red channel.\u003c\/li\u003e\n\u003cli\u003eAssign the \u003cstrong\u003eH-alpha\u003c\/strong\u003e image to the Green channel.\u003c\/li\u003e\n\u003cli\u003eAssign the \u003cstrong\u003eOIII\u003c\/strong\u003e image to the Blue channel.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eThis creates the classic gold-and-blue Hubble look, which you can then adjust for color balance and aesthetics.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Type\u003c\/td\u003e\n\u003ctd\u003eNarrowband Interference Filter Set\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eIncluded Filters\u003c\/td\u003e\n\u003ctd\u003eH-alpha, Oxygen III, Sulphur II\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBandpass (FWHM)\u003c\/td\u003e\n\u003ctd\u003e3nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCentral Wavelength (H-Alpha)\u003c\/td\u003e\n\u003ctd\u003e656nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCentral Wavelength (OIII)\u003c\/td\u003e\n\u003ctd\u003e500nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCoatings\u003c\/td\u003e\n\u003ctd\u003eMulti-layer, Anti-Reflection, Ion-Assisted Deposition\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\u003eAvailable Sizes\u003c\/td\u003e\n\u003ctd\u003e2\" Mounted, 36mm Round Unmounted\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eOptolong H-alpha 3nm Filter\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eOptolong OIII 3nm Filter\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eOptolong SII 3nm Filter\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eProtective Storage Case\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/optolong-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eOptolong 3-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Optolong","offers":[{"title":"2\" Mounted","offer_id":52941910901021,"sku":"OPT-SHO3NM-2","price":1199.0,"currency_code":"USD","in_stock":true},{"title":"36mm Round Unmounted","offer_id":52941910933789,"sku":"OPT-SHO3NM-RD36","price":960.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Optolong-2021-NEW-Optolong-SHO-3nm-narrowband-filters-kit-1_af14908b-fe74-4be0-a7b8-3d92151a6b1b.jpg?v=1789592322","url":"https:\/\/davidastro.com\/fr-us\/products\/optolong-sho-3nm-narrowband-filter-kit-3-pcs","provider":"David Astro","version":"1.0","type":"link"}