{"product_id":"svbony-sv227-sho-5nm-h-alpha-oiii-sii-narrowband-filter-set-125in","title":"SVBONY SV227 SHO 5nm H-Alpha OIII SII Narrowband Filter Set - 1.25\"","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eComplete 1.25-inch SHO (SII, H-Alpha, OIII) filter set\u003c\/li\u003e\n\u003cli\u003eTight 5nm bandpass for high-contrast imaging\u003c\/li\u003e\n\u003cli\u003ePeak transmission rate of ≥90% at key wavelengths\u003c\/li\u003e\n\u003cli\u003eOD5 blocking of light from 300-1000nm\u003c\/li\u003e\n\u003cli\u003e1\/4λ surface parallelism for sharp stars\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\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\u003eSVBONY SV227 1.25\" SHO 5nm Narrowband Filter Set\u003c\/h2\u003e\n\u003cp\u003eThe SVBONY SV227 1.25\" SHO 5nm Narrowband Filter Set delivers the essential tools for creating high-contrast Hubble Palette images of deep-sky emission nebulae. This complete set isolates the critical emission lines of Sulfur-II at 671.6nm, Hydrogen-alpha at 656.3nm, and Oxygen-III at 500.7nm with a tight 5nm bandpass. With a peak transmission of ≥90% and OD5 blocking across the 300-1000nm spectrum, these filters capture faint nebula details while aggressively rejecting light pollution and moonlight.\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\u003eIsolate Key Nebula Emissions with a 5nm Bandwidth\u003c\/h3\u003e\n\u003cp\u003eThe core of narrowband imaging is isolating the specific wavelengths of light emitted by ionized gases in space. The SV227 set provides three filters precisely centered on these lines: 656.3nm for H-alpha, 500.7nm for OIII, and 671.6nm for SII. A narrow 5nm bandpass dramatically increases contrast by rejecting continuum emission from stars and suppressing skyglow, making faint structures within nebulae like the Pillars of Creation in the Eagle Nebula (M16) stand out against a dark background.\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\u003e≥90% Peak Transmission and 1\/4λ Surface Parallelism\u003c\/h3\u003e\n\u003cp\u003eHigh transmission and optical precision are critical for capturing clean data. The SV227 filters ensure that over 90% of the targeted narrowband light reaches your sensor, minimizing exposure times. Each filter is polished to a 1\/4λ surface parallelism, which prevents the introduction of astigmatism or other aberrations, keeping star shapes tight and round across the entire 26mm clear aperture.\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\u003eOD5 Blocking for Imaging Under Light-Polluted Skies\u003c\/h3\u003e\n\u003cp\u003eFor imagers in urban or suburban locations, aggressive blocking of unwanted light is non-negotiable. The SV227 filters provide an optical density (OD) of 5, which blocks out 99.999% of all light outside the 5nm passband, from 300nm to 1000nm. This deep blocking effectively eliminates gradients from streetlights, moonlight, and general skyglow, allowing you to capture clean, high-signal data even under compromised sky conditions.\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\u003e1.85mm Substrate with M28.5x0.6 Threads\u003c\/h3\u003e\n\u003cp\u003eBuilt for reliability, each SV227 filter uses a 1.85mm thick glass substrate housed in a CNC-machined 6061T aluminum alloy cell. The standard M28.5x0.6 male threads ensure compatibility with any 1.25-inch filter wheel or drawer. The consistent 1.85mm thickness across the set helps maintain focus between filter changes, reducing the need for constant refocusing throughout an imaging session.\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\u003eWhy Choose a 5nm Filter Set Over Wider Bandpasses?\u003c\/h3\u003e\n\u003cp\u003eWhile wider filters (like 7nm or 12nm) can allow for slightly shorter sub-exposures, a 5nm bandpass offers a distinct advantage in contrast. The tighter window rejects more of the unwanted light immediately surrounding the emission line, which results in a darker sky background and smaller, more controlled stars. This trade-off makes the 5nm SV227 set an excellent choice for imagers prioritizing maximum detail and contrast, especially from light-polluted locations.\u003c\/p\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 primary advantage of the SVBONY SV227 5nm filter set?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe primary advantage is its tight \u003cstrong\u003e5nm bandpass\u003c\/strong\u003e. This provides extremely high contrast by isolating the specific H-alpha, OIII, and SII emission lines while rejecting nearly all other light, including light pollution and starlight. This results in a darker sky background and more prominent nebula detail compared to wider filters.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow will the SVBONY SV227 5nm filters perform on the Orion Nebula (M42) from a light-polluted suburb?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe SV227 filters are ideal for this scenario. The Orion Nebula (M42) is rich in H-alpha and OIII emissions. The \u003cstrong\u003eOD5 blocking\u003c\/strong\u003e will eliminate the vast majority of your suburban skyglow, and the 5nm bandpass will separate the faint, intricate structures of the nebula from the bright stars of the Trapezium, allowing you to capture far more detail than is possible with broadband or wider narrowband filters.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the SVBONY SV227 SHO set with my color camera and 80mm f\/6 refractor?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWhile technically possible, this set is designed and optimized for \u003cstrong\u003emonochrome astronomy cameras\u003c\/strong\u003e. Using these filters with a one-shot color (OSC) camera is highly inefficient, as the camera's color filter array will block most of the light that passes through the narrowband filter. For the best results and to create Hubble Palette images, you should pair the SV227 set with a monochrome camera and a filter wheel.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eAre the SVBONY SV227 filters parfocal with each other?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe filters in the SV227 set are manufactured to be nearly parfocal. They all use the same \u003cstrong\u003e1.85mm substrate thickness\u003c\/strong\u003e, which means that any focus shift when switching between the H-alpha, OIII, and SII filters should be minimal. This saves time during an imaging session as you won't need to perform a major refocus after every filter change.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat does OD5 blocking mean for the SV227 filters?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003e\u003cstrong\u003eOD5\u003c\/strong\u003e stands for Optical Density 5. This is a logarithmic scale meaning the filters block 10^5, or 100,000 times, the amount of unwanted light. In practical terms, it means they transmit only 0.001% of light outside their specified passband across a wide spectrum from 300nm to 1000nm, ensuring exceptional rejection of light pollution and moonlight.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhy does the SVBONY SV227 set include three separate storage cases?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eAs listed in the box contents, each of the three filters (H-alpha, SII, OIII) comes with its own protective \u003cstrong\u003ePP Storage Case\u003c\/strong\u003e. This prevents the filters from scratching or rubbing against each other during transport or storage and makes it easy to identify and handle them individually without exposing the others to dust or fingerprints.\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\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eSVBONY\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eProduct Name\u003c\/td\u003e\n\u003ctd\u003eSII \u0026amp; OIII \u0026amp; H-Alpha Filter Set\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSKU\u003c\/td\u003e\n\u003ctd\u003eW9187A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Size\u003c\/td\u003e\n\u003ctd\u003e1.25-Inch\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBandwidth\u003c\/td\u003e\n\u003ctd\u003e5nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTransmission Wavelengths\u003c\/td\u003e\n\u003ctd\u003e671.6nm (SII), 656.3nm (H-Alpha), 500.7nm (OIII)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePeak Transmission\u003c\/td\u003e\n\u003ctd\u003e≥90%\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBlocking Strength\u003c\/td\u003e\n\u003ctd\u003eOD5 @ 300-1000nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCut-off Depth\u003c\/td\u003e\n\u003ctd\u003eAverage ≥ OD5\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eClear Aperture\u003c\/td\u003e\n\u003ctd\u003e26mm\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\u003eSurface Parallelism\u003c\/td\u003e\n\u003ctd\u003e1\/4λ\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eParallelism\u003c\/td\u003e\n\u003ctd\u003e30\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSubstrate Thickness\u003c\/td\u003e\n\u003ctd\u003e1.85mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eThreads\u003c\/td\u003e\n\u003ctd\u003eM28.5x0.6 (Single Male Thread)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaterial\u003c\/td\u003e\n\u003ctd\u003e6061T Aluminum Alloy\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCell Finish\u003c\/td\u003e\n\u003ctd\u003eCNC Machined, Black Anodized\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Dimensions\u003c\/td\u003e\n\u003ctd\u003eΦ31.75 x 7mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNet Weight (per filter)\u003c\/td\u003e\n\u003ctd\u003e15g\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNet Weight (set)\u003c\/td\u003e\n\u003ctd\u003e140g\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\"\u003e1.25\" H-alpha Filter (5nm)\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\"\u003e1.25\" SII Filter (5nm)\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\"\u003e1.25\" OIII Filter (5nm)\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\"\u003ePP Storage Cases\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 3\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\/svbony-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eSVBONY 1-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"SVBONY","offers":[{"title":"Default Title","offer_id":52861237068061,"sku":"SV-W9187A","price":167.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/SVBONY-SV227-1-25-SHO-5nm-Narrowband-Filter-Set-for-Deep-Sky-1_eea5be8f-ad97-4327-a6bb-e8e103fa63cc.jpg?v=1788883698","url":"https:\/\/davidastro.com\/fr-us\/products\/svbony-sv227-sho-5nm-h-alpha-oiii-sii-narrowband-filter-set-125in","provider":"David Astro","version":"1.0","type":"link"}