{"product_id":"svbony-sv240-near-infrared-multi-narrowband-light-pollution-filter","title":"SVBONY SV240 Near-Infrared Multi-Narrowband Light Pollution Filter","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eDesigned for urban astrophotography with one-shot color cameras\u003c\/li\u003e\n\u003cli\u003ePasses H-Alpha, OIII, H-Beta, and Near-Infrared (NIR) wavelengths\u003c\/li\u003e\n\u003cli\u003ePeak transmittance over 95% for H-Alpha (656.3nm) and H-Beta (486.1nm)\u003c\/li\u003e\n\u003cli\u003eFeatures a wide 115nm FWHM bandpass in the NIR spectrum\u003c\/li\u003e\n\u003cli\u003eStandard 2-inch (M48x0.75) threaded cell\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 SV240 2\" NIR Multi Narrowband Filter\u003c\/h2\u003e\n\u003cp\u003eThe Svbony SV240 2\" NIR Multi Narrowband Filter is engineered for one-shot color imaging from light-polluted urban skies, capturing four critical spectral regions in a single exposure. This filter delivers peak transmittance of over 95% at H-Alpha (656.3nm) and H-Beta (486.1nm), and over 92% for OIII (495.9nm), while simultaneously opening a 115nm-wide window in the near-infrared with an average transmission greater than 95% between 830-870nm. Its 2mm substrate thickness and 1\/4λ surface parallelism ensure your optical system's sharpness is maintained, all within a standard M48x0.75 threaded cell.\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\u003eTriple-Bandpass Design: Over 92% Transmission on Key Nebula Lines\u003c\/h3\u003e\n\u003cp\u003eThe core of the SV240 is its ability to isolate the three most important emission nebula spectral lines from the glare of city lights. With a peak transmission of \u0026gt;95% at H-Alpha (656.3nm), \u0026gt;92% at OIII (495.9nm), and \u0026gt;95% at H-Beta (486.1nm), the filter gathers maximum signal from your target. This high transmission is paired with aggressive blocking of common light pollution sources, achieving \u0026gt;OD4 suppression in the 560-620nm range, effectively eliminating the orange glow from sodium vapor lamps.\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\u003eA 115nm Near-Infrared Window for Modern CMOS Sensors\u003c\/h3\u003e\n\u003cp\u003eUnlike traditional tri-band filters, the SV240 includes a fourth, wide passband in the near-infrared, spanning 830-870nm with an average transmission over 95%. This 115nm FWHM window is designed to leverage the high quantum efficiency of modern color CMOS sensors (like the Sony IMX585 and IMX464) in the NIR region. By capturing this additional signal, which is less affected by artificial light pollution, you can significantly boost the signal-to-noise ratio and contrast of your final image without complex processing. Note that imaging in the NIR band can sometimes introduce halos around bright stars, a known trade-off for the increased signal.\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\u003e2mm Substrate and 1\/4λ Parallelism for Sharp Stars\u003c\/h3\u003e\n\u003cp\u003eOptical precision is maintained by constructing the SV240 from a 2mm thick substrate with a surface parallelism of 1\/4λ. This ensures the filter will not introduce a significant focus shift or degrade the sharpness of your starfield, even in fast optical systems. The filter is housed in a standard 2-inch cell with M48x0.75 threads, making it compatible with most filter wheels, drawers, and camera nosepieces, while the 44mm clear aperture prevents vignetting on larger sensors.\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\u003eSvbony SV240 vs. SV220: Adding the H-Beta and NIR Bands\u003c\/h3\u003e\n\u003cp\u003eThe SV240 represents a significant evolution from a standard dual-bandpass filter like the Svbony SV220. While the SV220 is highly effective at isolating H-Alpha and OIII, the SV240 expands on this capability in two key ways.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eH-Beta Passband:\u003c\/strong\u003e The SV240 adds a dedicated passband for Hydrogen-Beta, crucial for capturing the full color and detail in objects like the Horsehead Nebula (Barnard 33) and California Nebula (NGC 1499).\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNear-Infrared (NIR) Window:\u003c\/strong\u003e The SV240's primary advantage is its 115nm-wide NIR passband. This feature is specifically designed for modern color cameras highly sensitive to NIR light, allowing you to gather more signal data from a broader range of targets, including galaxies and star-forming regions, than is possible with the SV220.\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\"\u003eHow does the Svbony SV240 filter's NIR band help with imaging the Orion Nebula (M42) from the city?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Orion Nebula (M42) has strong emissions in H-Alpha, OIII, and H-Beta, which the \u003cstrong\u003eSvbony SV240\u003c\/strong\u003e captures with \u0026gt;92% transmission. The added 115nm-wide NIR band captures additional signal from the star-forming regions deep within the nebula. Since urban light pollution has less impact in the NIR, this fourth band boosts your overall signal-to-noise ratio, revealing fainter details than a traditional tri-band filter could from the same location.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the Svbony SV240 a good choice for my color camera with an IMX585 sensor?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, it is an excellent choice. The \u003cstrong\u003eSvbony SV240\u003c\/strong\u003e was specifically designed with sensors like the Sony IMX585 in mind. These modern CMOS chips have very high quantum efficiency in the near-infrared. The filter's \u0026gt;95% average transmission in the 830-870nm range is designed to leverage this sensitivity, allowing you to collect significantly more data and achieve higher-contrast images.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat's the difference between the SV240 and a standard UHC or CLS filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eUHC and CLS (City Light Suppression) filters are broadband filters that pass a much wider range of the spectrum, which can still let significant light pollution through. The \u003cstrong\u003eSvbony SV240\u003c\/strong\u003e is a multi-narrowband filter with much tighter bandpasses (20nm and 24nm for OIII\/H-Beta and H-Alpha) that isolate specific emission lines with high precision. This results in much darker skies, higher contrast on nebulae, and the ability to image from more heavily light-polluted areas.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the SV240 filter with my 8\" f\/4 Newtonian for imaging galaxies like Andromeda (M31)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. While galaxies like Andromeda (M31) are broadband targets, the \u003cstrong\u003eSvbony SV240\u003c\/strong\u003e can still be very effective. It will capture the H-Alpha signal from the star-forming regions in the galaxy's spiral arms while suppressing city glow. The NIR band is also beneficial, as it captures signal from the older, redder star populations in the galactic core. The filter's 1\/4λ parallelism ensures it performs well with your fast f\/4 optics.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhy does the Svbony SV240 have three different FWHM values (24nm, 20nm, 115nm)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe different Full-Width Half-Maximum (FWHM) values correspond to the different passbands of the \u003cstrong\u003eSvbony SV240\u003c\/strong\u003e filter. The 24nm and 20nm bandpasses are for the visible light emission lines (H-Alpha, H-Beta, OIII), providing a tight but manageable window for capturing nebula detail. The much wider 115nm FWHM is for the near-infrared (NIR) band, designed to gather as much signal as possible from this region where modern sensors are highly sensitive.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill I need to refocus when using the 2mm thick Svbony SV240 filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003eSvbony SV240\u003c\/strong\u003e uses a 2mm thick substrate, which is a common standard. While any filter will shift the focal point slightly, a 2mm thickness is generally considered \"parfocal\" with many other modern filters. The shift will be minimal, but for critical sharpness, especially in fast telescopes, it is always best practice to check and refine focus after inserting any filter into the optical path.\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\u003eMulti-Narrowband Filter\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eModel\u003c\/td\u003e\n\u003ctd\u003eSV240\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSize\u003c\/td\u003e\n\u003ctd\u003e2-inch\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eThread\u003c\/td\u003e\n\u003ctd\u003eM48x0.75\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eClear Aperture\u003c\/td\u003e\n\u003ctd\u003e44mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSubstrate Thickness\u003c\/td\u003e\n\u003ctd\u003e2mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWavelength Range\u003c\/td\u003e\n\u003ctd\u003e300-1100nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFWHM\u003c\/td\u003e\n\u003ctd\u003e24nm \u0026amp; 20nm \u0026amp; 115nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePeak Transmittance\u003c\/td\u003e\n\u003ctd\u003eT＞95%@656.3nm (H-α)\u003cbr\u003eT＞95%@486.1nm (H-β)\u003cbr\u003eT＞92%@495.9nm (OIII)\u003cbr\u003eT\u0026gt;85%@500.7nm (OIII)\u003cbr\u003eTavg\u0026gt;95%@830-870nm (NIR)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBlocking\u003c\/td\u003e\n\u003ctd\u003e\u0026gt;OD5 @ 300-450nm\u003cbr\u003e\u0026gt;OD4 @ 560-620nm\u003cbr\u003e\u0026gt;OD2 @ 690-750nm\u003cbr\u003e\u0026gt;OD3 @ 940-1100nm\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\u003eSingle Thread\u003c\/td\u003e\n\u003ctd\u003eYes\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNet Weight\u003c\/td\u003e\n\u003ctd\u003e12.5g \/ 0.44oz\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\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":"1.25\" Round Mounted","offer_id":52861237199133,"sku":"SV-W9191B","price":126.0,"currency_code":"CAD","in_stock":true},{"title":"2\" Round Mounted","offer_id":52861237231901,"sku":"SV-W9191A","price":168.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/SVBONY-SV240-1-25-Multi-Narrowband-Filter-for-Urban-Astrophotography-1_9a989526-8ef6-408f-827e-43d86ba7f618.jpg?v=1788660312","url":"https:\/\/davidastro.com\/fr\/products\/svbony-sv240-near-infrared-multi-narrowband-light-pollution-filter","provider":"David Astro","version":"1.0","type":"link"}