{"title":"ZWO Filters","description":"\u003cp\u003eZWO filters cover deep-sky, planetary and camera protection needs. For deep-sky imaging there are LRGB Optimized filters, 7nm H-alpha, OIII and SII narrowband filters sold singly or as a set, and a Duo-Band filter for color cameras under light pollution.\u003c\/p\u003e\u003cp\u003ePlanetary imagers can use the CH4 methane 20nm filter and the IR 850nm pass filter. UV\/IR cut filters and IR-cut or AR protective windows keep dust off the sensor while shaping the spectrum.\u003c\/p\u003e","products":[{"product_id":"zwo-ch4-methane-filter-20nm-1-25","title":"ZWO CH4 Methane Filter - 20nm 1.25\"","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eReveals high-altitude detail on Jupiter and Saturn\u003c\/li\u003e\n\u003cli\u003e20nm bandpass centered on the methane absorption line\u003c\/li\u003e\n\u003cli\u003eStandard 1.25\" (31.75mm) threaded cell\u003c\/li\u003e\n\u003cli\u003eReduces effects of atmospheric seeing\u003c\/li\u003e\n\u003cli\u003e2-Year ZWO Warranty\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\u003eDownloads\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\u003eZWO 20nm CH4 Methane Band Filter - 1.25\"\u003c\/h2\u003e\n\u003cp\u003eThe ZWO CH4 Methane Filter isolates a specific 20nm bandpass deep in the near-infrared spectrum, targeting the strong methane absorption lines in the atmospheres of gas giants. Housed in a standard 1.25\" (31.75mm) threaded cell, this filter is purpose-built to reveal high-altitude clouds and storm systems on Jupiter and Saturn that are completely invisible in visible light.\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\u003eIsolating Planetary Detail with a 20nm Bandpass\u003c\/h3\u003e\n\u003cp\u003eThe 20nm FWHM (Full Width at Half Maximum) is precisely tuned to the methane (CH4) absorption band. When you image Jupiter, regions rich in methane absorb this wavelength of light and appear dark, while high-altitude features like the Great Red Spot or bright equatorial zones reflect this light strongly, creating dramatic contrast. This allows you to resolve atmospheric stratification and storm structures that are otherwise lost against the planet's brighter, lower-level cloud decks.\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\u003eSeeing-Resistant Imaging with a 1.25\" Filter\u003c\/h3\u003e\n\u003cp\u003eBecause this filter operates in the near-infrared, it leverages a key principle of atmospheric optics: longer wavelengths of light are less susceptible to distortion from air turbulence (\"seeing\"). On nights of average or poor seeing, the ZWO CH4 filter can deliver a steadier, sharper image than a standard luminance or color filter. This stability is critical for capturing fine planetary detail, making this 1.25\" filter an essential tool for dedicated planetary imagers.\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\u003eCompatibility and Use with Monochrome Cameras\u003c\/h3\u003e\n\u003cp\u003eThis is a specialized filter designed for monochrome cameras that have good sensitivity in the near-infrared. While it can be used with some IR-sensitive color cameras, the best results are achieved with a mono sensor where you can optimize exposure for this specific wavelength. The standard 1.25\" threaded cell ensures it fits any standard filter wheel, filter drawer, or 1.25\" nosepiece, making it a seamless addition to your existing imaging train.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eStandard Threads:\u003c\/strong\u003e The 1.25\" cell is threaded to screw directly into standard astronomical accessories.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMono Sensor Optimized:\u003c\/strong\u003e Achieves maximum contrast and detail when paired with a sensitive monochrome planetary camera.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProtective Case:\u003c\/strong\u003e Includes a durable plastic case to keep the filter safe and clean when not in use.\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 will the ZWO CH4 filter change my images of Jupiter's Great Red Spot?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Great Red Spot (GRS) is a high-altitude storm. With the \u003cstrong\u003eZWO CH4 filter\u003c\/strong\u003e, the GRS will appear exceptionally bright against the surrounding, darker methane-rich atmospheric belts. This dramatically increases its contrast and visibility, allowing you to capture its structure even when it appears washed out in visible-light images.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat camera do I need to use the ZWO 20nm CH4 filter with my telescope?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYou need an imaging camera with good sensitivity in the near-infrared (around 890nm, where methane absorbs). \u003cstrong\u003eMonochrome planetary cameras\u003c\/strong\u003e are the ideal choice as they typically have higher IR sensitivity than one-shot color cameras. Standard DSLRs are generally not sensitive enough at this wavelength without modification.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the ZWO CH4 filter for visual observing?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, this filter is designed for imaging only. The human eye is not sensitive to the near-infrared wavelengths that the ZWO CH4 filter transmits, so you would not be able to see anything through it visually.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the ZWO CH4 filter help with bad seeing conditions?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe filter passes light in the near-infrared part of the spectrum. These longer wavelengths are less distorted by turbulence in Earth's atmosphere (\"seeing\") compared to shorter, visible-light wavelengths. The result is a more stable image at the sensor, which often translates to sharper final images on nights with unsteady air.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill this 1.25\" ZWO CH4 filter fit my existing filter wheel?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The ZWO CH4 filter is housed in a standard \u003cstrong\u003e1.25\" (31.75mm) threaded cell\u003c\/strong\u003e. It will screw into any filter wheel, filter drawer, or accessory designed to accept standard 1.25\" astronomical filters.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the ZWO CH4 filter useful for planets other than Jupiter and Saturn?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWhile it is most effective on Jupiter and Saturn due to their prominent methane atmospheres, it can also be used to study the atmospheres of Uranus and Neptune. However, these ice giants are much dimmer and smaller, requiring larger telescopes and longer exposures to achieve good results.\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\u003eSKU\u003c\/td\u003e\n\u003ctd\u003eZWO-CH4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Type\u003c\/td\u003e\n\u003ctd\u003eCH4 (Methane) Band\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBandpass (FWHM)\u003c\/td\u003e\n\u003ctd\u003e20nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSize\u003c\/td\u003e\n\u003ctd\u003e31.75mm (1.25\")\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFormat\u003c\/td\u003e\n\u003ctd\u003eThreaded Round Cell\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eIntended Use\u003c\/td\u003e\n\u003ctd\u003ePlanetary Imaging\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWarranty\u003c\/td\u003e\n\u003ctd\u003e2 Years\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\"\u003eZWO CH4 20nm Methane Filter in 1.25\" Cell\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\"\u003ePlastic Filter 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\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/www.zwoastro.com\/software\/\" target=\"_blank\"\u003e\u003csvg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewbox=\"0 0 640 512\" class=\"DAV-img-box\"\u003e\u003cpath fill=\"#0047a7\" d=\"M128 32C92.7 32 64 60.7 64 96l0 256 64 0 0-256 384 0 0 256 64 0 0-256c0-35.3-28.7-64-64-64L128 32zM19.2 384C8.6 384 0 392.6 0 403.2C0 445.6 34.4 480 76.8 480l486.4 0c42.4 0 76.8-34.4 76.8-76.8c0-10.6-8.6-19.2-19.2-19.2L19.2 384z\"\u003e\u003c\/path\u003e\u003c\/svg\u003e \n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDownload ZWO Software\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/zwo-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eZWO 2-Year Limited Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"ZWO","offers":[{"title":"Default Title","offer_id":44967386022173,"sku":"ZWO-CH4","price":139.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/ZWO-20nm-CH4-Methane-Filter-1-25-inch-1__16094.1596910046.1280.1280.jpg?v=1684341754"},{"product_id":"zwo-ir-850nm-pass-filter-1-25","title":"ZWO IR 850nm Pass Filter – 1.25\"","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003ePasses Infrared Light \u0026gt; 850nm\u003c\/li\u003e\n\u003cli\u003eDramatically Steadies Planetary Views in Poor Seeing\u003c\/li\u003e\n\u003cli\u003eEnables Daylight Planetary and Lunar Imaging\u003c\/li\u003e\n\u003cli\u003eStandard 1.25\" (31.75mm) Threaded Filter Cell\u003c\/li\u003e\n\u003cli\u003eIncludes Protective Plastic Case\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\u003eDownloads\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\u003eZWO 850nm IR Pass Filter - 1.25\"\u003c\/h2\u003e\n\u003cp\u003eThe ZWO 850nm IR Pass Filter isolates a specific slice of the near-infrared spectrum, transmitting only wavelengths longer than 850nm. Housed in a standard 1.25\" (31.75mm) threaded cell, this filter is a specialized tool for high-resolution planetary and lunar imaging, effectively bypassing the atmospheric turbulence that blurs details in the visible spectrum.\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\u003eCut Through Bad Seeing at 850nm\u003c\/h3\u003e\n\u003cp\u003eAtmospheric turbulence, or \"seeing,\" is the primary obstacle to sharp planetary detail. Because longer wavelengths of light are less scattered by air currents, imaging at 850nm and beyond dramatically stabilizes the image. This allows you to resolve finer details in Jupiter's cloud bands, the Cassini Division in Saturn's rings, and subtle craterlets on the Moon, even when seeing conditions are poor or your target is low on the horizon.\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\u003eDaylight Planetary Imaging Beyond 850nm\u003c\/h3\u003e\n\u003cp\u003eBy aggressively blocking all visible light below 850nm, this filter renders the daytime sky nearly black to an IR-sensitive camera. This unique capability opens up the possibility of imaging bright planets like Venus and Jupiter during daylight hours. The result is a high-contrast image of the planet against a dark background, free from the glare of the blue sky.\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\u003eZWO 850nm vs. 685nm IR Pass: Which to Choose?\u003c\/h3\u003e\n\u003cp\u003eZWO offers multiple IR Pass filters, and the choice depends on your conditions and camera. The 850nm filter is the more specialized of the two most common options.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eZWO 685nm IR Pass:\u003c\/strong\u003e This filter allows more light to reach the sensor, resulting in a brighter image and shorter exposure times. It is a great all-around choice for improving detail in average-to-poor seeing and works well with a broader range of monochrome cameras.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eZWO 850nm IR Pass:\u003c\/strong\u003e This filter is the ultimate seeing-killer. When conditions are exceptionally turbulent, the 850nm passband delivers the steadiest possible image. The trade-off is a significantly dimmer signal, which requires a camera with high IR sensitivity and potentially higher gain settings to achieve focus and capture data.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eDesigned for IR-Sensitive Cameras in a 1.25\" Cell\u003c\/h3\u003e\n\u003cp\u003eThis filter is designed for astro-imaging with an IR-sensitive monochrome or color camera; the human eye is not sensitive to 850nm light, so it cannot be used for visual observation. Its performance is directly tied to the quantum efficiency of your camera in the near-infrared. For best results, pair the ZWO 850nm IR Pass filter with a mono camera known for strong IR response. The industry-standard 1.25\" (31.75mm) threaded cell fits any standard 1.25\" filter wheel or nosepiece.\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\"\u003eHow does the ZWO 850nm filter improve imaging of Jupiter on a turbulent night?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eOn nights with poor seeing, the Earth's atmosphere blurs the fine details of planets like Jupiter. The ZWO 850nm filter blocks the shorter, more easily scattered visible wavelengths and only lets the steadier, longer-wavelength infrared light through. This results in a much more stable image on your sensor, allowing you to capture sharper details in the Great Red Spot and equatorial cloud bands that would otherwise be a shimmering mess.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the ZWO 850nm IR Pass filter with my color astronomy camera to image the Moon?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, if the camera has good near-infrared sensitivity. Beyond 850nm the red, green and blue pixels of a color sensor respond almost equally, so ZWO notes that a color camera such as the ASI224MC or ASI185MC can be used like a mono camera with this filter (keep white balance at 50). The signal is dim, so a camera with strong IR response, mono or color, gives the best results.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the ZWO 850nm filter suitable for visual observation?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo. The human eye cannot see light at a wavelength of 850nm. Looking through an eyepiece with this filter attached will result in a completely black field of view. It is a specialized tool designed exclusively for use with an infrared-sensitive astronomy camera.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the main difference between the ZWO 850nm and a 685nm IR Pass filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe primary difference is how aggressively they cut off visible light.\n\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eA \u003cstrong\u003e685nm filter\u003c\/strong\u003e is a good general-purpose choice, offering a significant improvement in seeing with a relatively bright signal.\u003c\/li\u003e\n\u003cli\u003eThe \u003cstrong\u003e850nm filter\u003c\/strong\u003e provides maximum seeing stabilization for the most turbulent conditions but passes much less light, requiring a very IR-sensitive camera and longer exposures or higher gain.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhy would I want to image planets during the day with the ZWO 850nm filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eImaging during the day allows you to capture planets when they are at their highest point in the sky, where atmospheric distortion is at a minimum. The ZWO 850nm filter makes this possible by blocking the visible light that makes the sky appear blue, effectively creating a dark background for your camera and allowing bright planets like Venus or Jupiter to be imaged in high contrast.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDoes the ZWO 850nm filter require a filter wheel?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, a filter wheel is not required. The filter's 1.25\" cell is threaded to screw directly onto any standard 1.25\" camera nosepiece or accessory. However, using it in a filter wheel makes it easy to switch between the 850nm filter and other filters (like LRGB) without disassembling your imaging train.\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\u003eSKU\u003c\/td\u003e\n\u003ctd\u003eZWO-850IR1.25\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Type\u003c\/td\u003e\n\u003ctd\u003eIR Pass \/ Luminance\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSize\u003c\/td\u003e\n\u003ctd\u003e31.75mm (1.25\")\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFormat\u003c\/td\u003e\n\u003ctd\u003eThreaded, Round\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePassband\u003c\/td\u003e\n\u003ctd\u003e\u0026gt; 850nm\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\"\u003eZWO 850nm IR Pass Filter in 1.25\" Cell\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\"\u003ePlastic Filter 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\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/www.zwoastro.com\/software\/\" target=\"_blank\"\u003e\u003csvg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewbox=\"0 0 640 512\" class=\"DAV-img-box\"\u003e\u003cpath fill=\"#0047a7\" d=\"M128 32C92.7 32 64 60.7 64 96l0 256 64 0 0-256 384 0 0 256 64 0 0-256c0-35.3-28.7-64-64-64L128 32zM19.2 384C8.6 384 0 392.6 0 403.2C0 445.6 34.4 480 76.8 480l486.4 0c42.4 0 76.8-34.4 76.8-76.8c0-10.6-8.6-19.2-19.2-19.2L19.2 384z\"\u003e\u003c\/path\u003e\u003c\/svg\u003e \n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDownload Software\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"https:\/\/davidastro.com\/pages\/zwo-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eZWO 2-Year Limited Warranty\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"ZWO","offers":[{"title":"Default Title","offer_id":44967439859997,"sku":"ZWO-850IR1-25","price":40.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/ZWO-IR-850nm-Pass-Filter-1-25-inch-1__82864.1596910056.1280.1280.jpg?v=1684341991"},{"product_id":"zwo-lrgb-optimized-filters","title":"ZWO LRGB Optimized Filters","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e1.25\" (31.75mm) Threaded Filter Set\u003c\/li\u003e\n\u003cli\u003eGreater than 92% Transmission at Passband\u003c\/li\u003e\n\u003cli\u003eBalanced 1:1:1 RGB Exposure Weighting\u003c\/li\u003e\n\u003cli\u003e1\/4 Wavefront Polished Optical Glass\u003c\/li\u003e\n\u003cli\u003e700-1100nm Infrared Wavelength Cut-Off\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\u003eZWO LRGB 1.25\" Premium Filter Set\u003c\/h2\u003e\n\u003cp\u003eThe ZWO LRGB 1.25\" Premium Filter Set delivers exceptional color fidelity and high-contrast data by ensuring over 92% light transmission across the critical passbands. Each filter is fine-optically polished to 1\/4 wavefront accuracy to preserve the sharpness of your telescope's optics. The set's precise 700-1100nm infrared cut-off and approximately 1:1:1 RGB color weighting simplify both image capture and processing, yielding brilliant results with modern CMOS cameras.\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\u003eOver 92% Transmission \u0026amp; 1:1:1 Color Balance\u003c\/h3\u003e\n\u003cp\u003eThis filter set captures faint signal efficiently, with each filter transmitting more than 92% of the light in its target wavelength. This high throughput reduces necessary exposure times, improving your overall signal-to-noise ratio. The coatings are engineered for an approximate 1:1:1 RGB color balance, allowing you to use similar exposure durations for each color channel and spend less time correcting color gradients in post-processing.\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\/4 Wavefront Accuracy for Maximum Sharpness\u003c\/h3\u003e\n\u003cp\u003eA filter is part of your telescope's optical train, and low-quality glass can degrade an otherwise sharp image. ZWO polishes these filters to a 1\/4 wavefront standard, ensuring they do not introduce aberrations or soften star images. Paired with multiple layers of anti-reflection coatings, this optical precision maintains high contrast and protects fine details in planetary and deep-sky targets.\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\u003ePrecision Off-Band Blocking Down to 700nm\u003c\/h3\u003e\n\u003cp\u003eModern monochrome CMOS sensors are highly sensitive to infrared light, which can cause star bloat and wash out color data if not properly blocked. This LRGB set features a sharp IR cut-off at 700nm, eliminating this issue entirely. The filters also incorporate a small spectral gap between the transmission bands, which helps to reject common sources of urban light pollution and further darken the sky 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\u003eZWO Premium vs. Standard LRGB Filters\u003c\/h3\u003e\n\u003cp\u003eWhile ZWO's standard filters offer an excellent entry into LRGB imaging, the Premium set is a significant step up in optical design for the discerning astrophotographer.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBetter Color Separation:\u003c\/strong\u003e The Premium filters have sharper cutoffs, which reduces wavelength overlap between channels for richer, more distinct colors.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHigher Transmission:\u003c\/strong\u003e With \u0026gt;92% transmission, the Premium filters gather more light than the standard versions, enabling deeper shots in the same amount of time.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSimplified Processing:\u003c\/strong\u003e The 1:1:1 color balance of the Premium set is a key advantage, removing the need for significant color weighting corrections that are often required with the standard set.\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 ZWO Premium LRGB filters over the standard set?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe primary advantages are higher transmission (\u0026gt;92%), better color separation from superior coatings, and a carefully engineered 1:1:1 color balance. This balance simplifies processing by allowing you to use roughly equal exposure times for the Red, Green, and Blue filters, resulting in a more natural color image with less correction needed.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhy is the 1\/4 wavefront accuracy important for the ZWO Premium LRGB filters?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eA \u003cstrong\u003e1\/4 wavefront\u003c\/strong\u003e specification means the filter's surface is extremely flat and will not distort the light passing through it. This preserves the native optical quality of your telescope, ensuring that stars remain as sharp and point-like as possible. Lower quality filters can introduce optical errors, softening the final image.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDo the ZWO Premium LRGB filters work well with cameras other than the ASI1600?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. While they were originally optimized for the popular ZWO ASI1600MM, their transmission curves, 1:1:1 color balance, and IR-cut features are beneficial for nearly any modern monochrome astronomy camera. They are an excellent match for sensors from Sony, Gpixel, and others.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the IR-cut feature on this ZWO LRGB filter set help my images?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eMonochrome sensors are sensitive to infrared (IR) light, which focuses at a different point than visible light. Unfiltered IR causes bloated, soft-looking stars and reduces overall image contrast. The sharp \u003cstrong\u003e700-1100nm\u003c\/strong\u003e IR cut-off on these filters completely blocks this unwanted light, leading to tighter stars and more accurate color data.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow will this ZWO LRGB filter set perform on the Andromeda Galaxy (M31) from a suburban location?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThis set is well-suited for imaging M31 from suburban skies. The Luminance filter will capture fine detail in the dust lanes with high transmission, while the RGB filters will gather color from the core and star-forming regions. The small spectral gaps between the filter passbands help to reject common light pollution sources, increasing the contrast between the galaxy and the skyglow.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill the 1.25\" ZWO LRGB filters cause vignetting on my full-frame camera and f\/5 refractor?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, significant vignetting is likely in that scenario. 1.25\" filters are best suited for Four Thirds or smaller sensors; on APS-C sensors they will vignette, so 36mm or 2\" filters are needed there. For a full-frame sensor, especially in a fast f\/5 optical system, 2\" threaded filters are strongly recommended to ensure the entire sensor is illuminated.\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\u003eSKU\u003c\/td\u003e\n\u003ctd\u003eZWO-LRGB125NEW\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Type\u003c\/td\u003e\n\u003ctd\u003eLRGB Filter Set\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSize\u003c\/td\u003e\n\u003ctd\u003e31.75mm (1.25\")\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFormat\u003c\/td\u003e\n\u003ctd\u003eThreaded, Round\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAccessory Type\u003c\/td\u003e\n\u003ctd\u003eFilter Set\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWarranty\u003c\/td\u003e\n\u003ctd\u003eZWO 2-Year Warranty\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\" Luminance (UV-IR) 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\"\u003e1.25\" Red 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\"\u003e1.25\" Green 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\"\u003e1.25\" Blue Filter\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\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/zwo-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eZWO 2-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"ZWO","offers":[{"title":"1.25\" Round Mounted","offer_id":44967440744733,"sku":"ZWO-LRGB1.25NEW","price":207.0,"currency_code":"CAD","in_stock":true},{"title":"2\" Round Mounted","offer_id":44967440810269,"sku":"ZWO-LRGB2","price":419.0,"currency_code":"CAD","in_stock":true},{"title":"36mm Round Unmounted","offer_id":44967440875805,"sku":"ZWO-LRGB36","price":279.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/ZWO-LRGB-Filters-Optimized-1-25-inch__12893.1596923433.1280.1280.jpg?v=1684341994"},{"product_id":"zwo-narrowband-filter-set-7nm-h-alpha-oiii-sii","title":"ZWO Narrowband Filter Set - 7nm H-alpha, OIII \u0026 SII","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eIncludes 1.25\" H-alpha, OIII, and SII filters\u003c\/li\u003e\n\u003cli\u003e7nm bandpass for high-contrast imaging\u003c\/li\u003e\n\u003cli\u003eIdeal for creating \"Hubble Palette\" images\u003c\/li\u003e\n\u003cli\u003eFine-optically polished to 1\/4 wave accuracy\u003c\/li\u003e\n\u003cli\u003eAbout 90% light transmission at the emission line\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\u003eZWO 1.25\" Narrowband Filter Set - 7nm H-alpha, OIII \u0026amp; SII\u003c\/h2\u003e\n\u003cp\u003eThe ZWO 1.25\" Narrowband Filter Set isolates the three most critical emission lines for deep-sky astrophotography with a tight 7nm bandpass. This set includes filters for Hydrogen-alpha (H-a) at 656nm, doubly-ionized Oxygen (OIII) at 500nm, and singly-ionized Sulfur (SII) at 672nm. Each filter is fine-optically polished to 1\/4 wave accuracy and features multi-layer anti-reflection coatings to achieve about 90% light transmission, ensuring maximum signal reaches your monochrome camera sensor.\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\u003eIsolating Nebulosity with a 7nm Bandpass\u003c\/h3\u003e\n\u003cp\u003eA 7nm bandpass is the key to high-contrast nebula imaging, especially from light-polluted locations. By transmitting only a razor-thin slice of the spectrum around the target emission line, these filters reject broadband light from streetlights, moonlight, and the general skyglow background. The result is a dramatic increase in contrast, revealing faint, intricate structures in emission nebulae like the Veil Nebula (NGC 6960) or the Heart Nebula (IC 1805) that would be invisible in a standard LRGB image.\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\u003eCreate Hubble Palette Images with 656nm, 500nm, and 672nm Filters\u003c\/h3\u003e\n\u003cp\u003eThis specific combination of H-a, OIII, and SII filters is the foundation of the iconic \"Hubble Palette.\" By mapping the data from each filter to a different color channel (typically SII to red, H-a to green, and OIII to blue), you can create vibrant, scientifically informative images that reveal the chemical composition of a nebula. The 672nm SII filter traces the coolest ionized gas, the 656nm H-a filter captures the most abundant hydrogen, and the 500nm OIII filter highlights the hottest, most energetic regions, giving your images incredible depth and color separation.\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\u003eOptical Precision: 1\/4 Wave Polish and 90% Transmission\u003c\/h3\u003e\n\u003cp\u003eImage quality is maintained by polishing each filter to a 1\/4 wave standard, ensuring the wavefront from your telescope's optics passes through without distortion, preserving star sharpness. With light transmission of about 90% within the narrow 7nm bandpass, the filters capture a strong signal from nebulae without requiring excessively long sub-exposure times. This balance makes the ZWO 7nm set a highly efficient choice for capturing deep-sky data.\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\u003eZWO 7nm vs. Tighter 3nm Bandpass Filters\u003c\/h3\u003e\n\u003cp\u003eWhen choosing narrowband filters, a common question is the ideal bandpass. While more expensive 3nm filters offer slightly higher contrast and even better rejection of light pollution, the ZWO 7nm filters present a more practical starting point for many imagers.\n\u003c\/p\u003e\n\u003cul\u003e\n \u003cli\u003e\n\u003cstrong\u003eSignal:\u003c\/strong\u003e Both bandpasses pass nearly all of the target emission line; the extra light a 7nm filter admits is mostly sky background, so 3nm filters give better contrast under light pollution.\u003c\/li\u003e\n \u003cli\u003e\n\u003cstrong\u003eSystem Compatibility:\u003c\/strong\u003e Tighter filters can sometimes introduce artifacts or be less effective with very fast optical systems (f\/4 and below) without careful setup. The 7nm bandpass is more forgiving across a wider range of telescope focal ratios.\u003c\/li\u003e\n \u003cli\u003e\n\u003cstrong\u003eCost-Effectiveness:\u003c\/strong\u003e For imagers moving from LRGB or one-shot color, the 7nm set delivers the vast majority of the benefits of narrowband imaging at a more accessible price point.\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\"\u003eCan I use the ZWO 7nm Narrowband filter set with a color camera?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNarrowband filters are designed for \u003cstrong\u003emonochrome cameras\u003c\/strong\u003e. A color camera has a Bayer matrix (a grid of red, green, and blue filters) over its sensor. Using a narrowband filter, like H-alpha which is deep red, would only allow light to pass through the red pixels, wasting the signal from the green and blue pixels and resulting in a very inefficient, low-resolution image.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow will the ZWO 7nm filters perform on the Orion Nebula (M42) from my backyard?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe ZWO 7nm filters will perform exceptionally well. M42 is extremely bright in both H-alpha and OIII. From a light-polluted backyard, these filters will darken the sky background significantly, allowing you to use longer exposures to capture the faint outer structures of the nebula without washing out the core. You will be able to resolve the intricate details within the Trapezium region with far more contrast than with standard LRGB filters.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat are the best deep-sky objects for this ZWO narrowband filter set?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThis set is ideal for \u003cstrong\u003eemission nebulae\u003c\/strong\u003e, which are clouds of ionized gas. Excellent targets include:\n\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eNorth America Nebula (NGC 7000):\u003c\/strong\u003e Rich in H-alpha and SII.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eVeil Nebula Complex (NGC 6960\/6992):\u003c\/strong\u003e A supernova remnant that glows brightly in H-alpha and OIII.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEagle Nebula (M16):\u003c\/strong\u003e Famous for the \"Pillars of Creation,\" which are stunning in the Hubble Palette.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHeart and Soul Nebulae (IC 1805 \u0026amp; IC 1848):\u003c\/strong\u003e Large complexes that are perfect for wider-field scopes.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eGalaxies and reflection nebulae are not good targets for these filters as they emit broadband light.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDo I need a filter wheel to use the ZWO 1.25\" filter set?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eA filter wheel is the most convenient way to automate switching between the H-a, OIII, and SII filters during an imaging session. However, it is not strictly necessary. You can also use a manual filter drawer or a filter slider, which allows you to swap the 1.25\" threaded filters by hand between exposures.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the \"Hubble Palette\" and how do I create it with these ZWO filters?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Hubble Palette, also known as \"SHO,\" is a color mapping technique used to visualize the different gases in a nebula. After capturing separate images with each of the ZWO filters, you combine them in post-processing software like PixInsight or Photoshop. The standard mapping is:\n\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eS-II Data → Red Channel\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eH-a Data → Green Channel\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eO-III Data → Blue Channel\u003c\/strong\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eThis creates the iconic gold-and-teal aesthetic seen in many images from the Hubble Space Telescope.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhy would I choose this ZWO 7nm set over a more expensive 3nm set?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWhile 3nm filters offer the highest possible contrast, the 7nm set is often a better choice for practicality. The ZWO 7nm filters pass nearly the same emission-line signal as 3nm filters; the extra light they admit is mostly sky background. They are \u003cstrong\u003emore forgiving\u003c\/strong\u003e on fast optical systems and more affordable, providing an excellent entry into serious narrowband imaging.\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\u003eSKU\u003c\/td\u003e\n\u003ctd\u003eZWO-NB7NMD1.25\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eProduct Type\u003c\/td\u003e\n\u003ctd\u003eFilter Set\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Class\u003c\/td\u003e\n\u003ctd\u003eNarrowband\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSize\u003c\/td\u003e\n\u003ctd\u003e31.75mm (1.25\")\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eShape\u003c\/td\u003e\n\u003ctd\u003eRound\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMounting Style\u003c\/td\u003e\n\u003ctd\u003eThreaded Cell\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBandwidth\u003c\/td\u003e\n\u003ctd\u003e7 nm\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\" Mounted H-a 7nm 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\"\u003e1.25\" Mounted OIII 7nm 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\"\u003e1.25\" Mounted SII 7nm 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\"\u003ePlastic Storage Box\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\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/zwo-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eZWO 2-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"ZWO","offers":[{"title":"1.25\" Round Mounted","offer_id":44967443366173,"sku":"ZWO-NB7nm1.25","price":517.0,"currency_code":"CAD","in_stock":true},{"title":"2\" Round Mounted","offer_id":44967443398941,"sku":"ZWO-NB7nm2","price":979.0,"currency_code":"CAD","in_stock":true},{"title":"36mm Round Unmounted","offer_id":44967443464477,"sku":"ZWO-NB7nmD36","price":671.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/ZWO-Narrowband-Filter-Set-1-25-inch__67133.1596920829.1280.1280.jpg?v=1684342071"},{"product_id":"zwo-narrowband-h-alpha-filter-7nm","title":"ZWO Narrowband H-alpha Filter - 7nm","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eIsolates Hydrogen-Alpha light at a 7nm bandpass\u003c\/li\u003e\n\u003cli\u003eStandard 1.25\" threaded metal cell\u003c\/li\u003e\n\u003cli\u003eBlocks light pollution and moonlight for extreme contrast\u003c\/li\u003e\n\u003cli\u003eMulti-layer anti-reflection coatings\u003c\/li\u003e\n\u003cli\u003eFine-optically polished to 1\/4 wave accuracy\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\u003eDownloads\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\u003eZWO H-Alpha 7nm CCD Filter - 1.25\"\u003c\/h2\u003e\n\u003cp\u003eThe ZWO H-Alpha 7nm CCD Filter isolates the most important emission line in astrophotography within a tight 7nm bandpass, designed for standard 1.25\" filter wheels and camera nosepieces. This single-filter solution provides the highest contrast on emission nebulae for monochrome imaging setups and is protected by a 2-year warranty.\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\u003eIsolating Nebulae with a 7nm Bandpass\u003c\/h3\u003e\n\u003cp\u003eBy passing only a 7nm window of light centered on the 656nm Hydrogen-alpha wavelength, this ZWO filter creates a near-black sky background. This surgical isolation dramatically increases the contrast of emission nebulae like the Orion Nebula (M42) or the North American Nebula (NGC 7000), making their faint structures visible even under severe moonlight or urban light pollution.\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\u003eOptical Precision at 1\/4 Wave\u003c\/h3\u003e\n\u003cp\u003eEach ZWO narrowband filter is fine-optically polished to a 1\/4 wave accuracy, ensuring that the filter itself does not degrade the sharpness of your optical train. Multi-layer anti-reflection coatings are applied to further suppress internal reflections, which prevents the halos and ghosting around bright stars that can compromise lesser filters.\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\u003eZWO 7nm vs. 3nm H-alpha Filters\u003c\/h3\u003e\n\u003cp\u003eChoosing a bandpass involves a direct trade-off between signal strength and contrast. While a 3nm filter provides the highest contrast and rejection of light pollution, both pass nearly all of the H-alpha emission; the extra light a 7nm filter admits is mostly sky background. The 7nm filter is more affordable and more forgiving on fast optical systems, which makes it a more balanced choice for a wider range of setups.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eZWO 3nm H-alpha:\u003c\/strong\u003e Offers maximum contrast for extremely light-polluted skies or for resolving the finest filamentary details in bright nebulae like the Veil Nebula. Costs more and is less forgiving on very fast optical systems.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eZWO 7nm H-alpha:\u003c\/strong\u003e More affordable and more forgiving on faster optical systems (f\/4-f\/7). It still provides excellent contrast, far exceeding broadband filters.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eCompatibility with Any 1.25\" System\u003c\/h3\u003e\n\u003cp\u003eThe filter is mounted in a durable, threaded metal cell that conforms to the standard 1.25\" filter format. This ensures it will thread directly into any 1.25\" filter wheel, manual filter drawer, or camera nosepiece that accepts filters, providing a secure, tilt-free fit in your imaging train.\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 ZWO H-alpha 7nm filter used for?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe ZWO H-alpha 7nm filter is designed for astrophotography with monochrome cameras. It isolates the specific wavelength of light emitted by ionized hydrogen (656nm), which is prevalent in star-forming regions and emission nebulae. This dramatically increases contrast and allows you to capture detailed images of nebulae, even from light-polluted locations.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the ZWO H-alpha 7nm filter with a color camera?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWhile you can, it's not ideal. A narrowband filter like this blocks almost all light except for a thin 7nm slice of deep red. A color camera's Bayer matrix has red, green, and blue pixels, so the green and blue pixels will receive no signal. You will get a monochrome red image with only 1\/4 of the camera's resolution. For color cameras, a multi-bandpass filter like the ZWO Duo-Band is a much more effective choice.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhy choose a 7nm filter over a tighter 3nm ZWO filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe 7nm bandpass is a trade-off. Both filters pass nearly all of the H-alpha emission; the extra light a 7nm filter admits is mostly sky background. The 7nm filter is more affordable and more forgiving on fast optical systems, while a 3nm filter offers higher contrast, which matters most under heavy light pollution or moonlight.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the ZWO 7nm H-alpha filter perform on the Orion Nebula (M42) from the city?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eIt performs exceptionally well. The 7nm bandpass will reject the vast majority of urban light pollution (which is primarily broadband), darkening the sky background significantly. This will make the faint outer loops of M42 stand out clearly while preventing the bright core of the Trapezium from being completely blown out, allowing you to capture a much higher dynamic range image.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat exposure times can I expect for the Cygnus Wall in NGC 7000 with this 7nm filter and an f\/5 refractor?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWith a typical monochrome CMOS camera (like a ZWO ASI294MM Pro) on an f\/5 refractor, you can expect to get a strong signal on the Cygnus Wall region of the North American Nebula (NGC 7000) with sub-exposures of 180 to 300 seconds. The 7nm bandpass allows for reasonably short exposures while still providing excellent contrast against the skyglow.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use this ZWO filter for viewing the Sun?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003e\u003cstrong\u003eAbsolutely not.\u003c\/strong\u003e This is an imaging filter for night-sky objects only. It is not a solar filter and provides no protection from harmful UV or infrared radiation. Attempting to view the sun with this filter will cause immediate and permanent eye damage and will destroy your camera sensor. Always use a certified solar filter that covers the entire front of your telescope for any solar observation.\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\u003eSKU Number\u003c\/td\u003e\n\u003ctd\u003eZWO-Ha7NM1.25\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Type\u003c\/td\u003e\n\u003ctd\u003eH-Alpha\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Size\u003c\/td\u003e\n\u003ctd\u003e31.75mm (1.25\")\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBandwidth\u003c\/td\u003e\n\u003ctd\u003e7 nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Format\u003c\/td\u003e\n\u003ctd\u003eSingle Filter\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eShape\u003c\/td\u003e\n\u003ctd\u003eRound\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMounting Style\u003c\/td\u003e\n\u003ctd\u003eThreaded Cell\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWarranty\u003c\/td\u003e\n\u003ctd\u003e2 Years\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\" Mounted H-Alpha 7nm 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 Plastic 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\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/www.zwoastro.com\/software\/\" target=\"_blank\"\u003e\u003csvg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewbox=\"0 0 640 512\" class=\"DAV-img-box\"\u003e\u003cpath fill=\"#0047a7\" d=\"M128 32C92.7 32 64 60.7 64 96l0 256 64 0 0-256 384 0 0 256 64 0 0-256c0-35.3-28.7-64-64-64L128 32zM19.2 384C8.6 384 0 392.6 0 403.2C0 445.6 34.4 480 76.8 480l486.4 0c42.4 0 76.8-34.4 76.8-76.8c0-10.6-8.6-19.2-19.2-19.2L19.2 384z\"\u003e\u003c\/path\u003e\u003c\/svg\u003e \n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDownload ZWO Software\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"https:\/\/davidastro.com\/pages\/zwo-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eZWO 2-Year Limited Warranty\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"ZWO","offers":[{"title":"1.25\" Round Mounted","offer_id":44967443562781,"sku":"ZWO-Ha7nm1.25","price":181.0,"currency_code":"CAD","in_stock":true},{"title":"2\" Round Mounted","offer_id":44967443595549,"sku":"ZWO-Ha7nm2","price":349.0,"currency_code":"CAD","in_stock":true},{"title":"36mm Round Unmounted","offer_id":44967443661085,"sku":"ZWO-Ha7nmD36","price":237.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/ZWO-H-alpha-Filter-1-25-inch__66275.1596920478.1280.1280.jpg?v=1684342084"},{"product_id":"zwo-narrowband-oiii-filter-7nm","title":"ZWO Narrowband OIII Filter - 7nm","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e7nm Bandpass at OIII Emission Line\u003c\/li\u003e\n\u003cli\u003eIsolates Planetary Nebulae and Supernova Remnants\u003c\/li\u003e\n\u003cli\u003eStandard 1.25\" Threaded Filter Cell\u003c\/li\u003e\n\u003cli\u003e1\/4 Wave Optical Substrate Accuracy\u003c\/li\u003e\n\u003cli\u003eMulti-Layer Anti-Reflection Coatings\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\u003eZWO OIII 7nm Narrowband Filter - 1.25\"\u003c\/h2\u003e\n\u003cp\u003eThe ZWO OIII 7nm 1.25\" Filter isolates the critical doubly-ionized oxygen emission line with a precise 7nm bandpass, dramatically increasing contrast on key deep-sky targets. Mounted in a standard 31.75mm threaded cell, its glass substrate is polished to an accuracy of 1\/4 wave to preserve the fine details resolved by your telescope.\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\u003eTargeting Emission Nebulae with a 7nm Bandpass\u003c\/h3\u003e\n\u003cp\u003ePlanetary nebulae and many supernova remnants are strong emitters in the OIII line near 500nm. This ZWO filter uses a 7nm bandpass to reject broadband light pollution from city skies and unwanted starlight, making faint structures like the Veil Nebula (NGC 6960) or the Dumbbell Nebula (M27) stand out against a dark background. The 7nm window is wide enough to be effective with faster optical systems while still delivering a significant contrast boost.\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\/4 Wave Optics for High-Resolution Imaging\u003c\/h3\u003e\n\u003cp\u003eA filter should only transmit light, not distort it. ZWO's narrowband filters are built on a fine-optically polished substrate with 1\/4 wave accuracy, ensuring the filter does not degrade the sharpness of your optical train. Multi-layer anti-reflection coatings maximize light transmission at the OIII wavelength and suppress internal reflections that can cause halos around bright stars.\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\u003eBuilding the Hubble Palette with a 1.25\" Filter\u003c\/h3\u003e\n\u003cp\u003eThe OIII filter is an essential component for creating tri-color \"Hubble Palette\" images when combined with H-alpha and SII filters. The standard 1.25\" (31.75mm) threaded cell is compatible with most astronomy cameras and filter wheels designed for smaller format sensors. While ideal for many setups, be aware that 1.25\" filters may introduce vignetting on cameras with APS-C or larger sensors, especially in fast f-ratio telescopes.\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 types of objects are best for the ZWO OIII 7nm filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThis filter excels at isolating structures in emission nebulae that are rich in doubly-ionized oxygen. Prime targets include \u003cstrong\u003eplanetary nebulae\u003c\/strong\u003e like the Ring Nebula (M57) and the Dumbbell Nebula (M27), and \u003cstrong\u003esupernova remnants\u003c\/strong\u003e such as the Veil Nebula (NGC 6960) and the Crab Nebula (M1).\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the 7nm bandpass on the ZWO OIII filter compare to a 3nm or 5nm filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eA \u003cstrong\u003e7nm bandpass\u003c\/strong\u003e offers a great balance between performance and flexibility. It provides a major contrast boost over a broadband filter but is more forgiving with faster focal ratio telescopes. A 3nm or 5nm filter passes nearly the same OIII signal while rejecting more light pollution, giving higher contrast on faint details, but it performs best with slower optical systems.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill this 1.25\" ZWO OIII filter work with my full-frame camera?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eIt is not recommended. While the 1.25\" filter will thread into compatible nosepieces, it is too small to fully illuminate a full-frame sensor (or even most APS-C sensors) without significant vignetting, which appears as a darkening of the corners of the image. For larger sensors, a 2\" or larger filter is required to achieve an evenly illuminated field.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhen imaging the Veil Nebula (NGC 6960) with an 8\" SCT, is this ZWO OIII filter a good choice?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, it's an excellent choice. The Veil Nebula is extremely rich in OIII emission, and this filter will make its delicate, filamentary structure pop against the sky background. An 8\" SCT at f\/10 or f\/6.3 provides an ideal focal ratio for the 7nm bandpass, allowing you to capture high-contrast details in this classic supernova remnant.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the ZWO OIII 7nm filter for visual observing?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, narrowband filters can be used visually with great effect, especially on planetary nebulae. By threading the 1.25\" filter onto your eyepiece, you can dramatically increase the contrast of objects like the Ring Nebula (M57), often making it visible from suburban skies where it would otherwise be washed out.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow do I create a \"Hubble Palette\" image with this ZWO OIII filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eTo create a Hubble Palette (SHO) image, you need to capture data through three different narrowband filters:\n\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSulfur-II (SII):\u003c\/strong\u003e This data is typically mapped to the Red channel.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHydrogen-alpha (H-alpha):\u003c\/strong\u003e This data is mapped to the Green channel.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOxygen-III (OIII):\u003c\/strong\u003e This ZWO filter provides data for the Blue channel.\u003c\/li\u003e\n\u003c\/ul\u003e\nBy combining these three monochrome images in processing software, you create a false-color result that reveals intricate details and structure within the nebula.\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\u003eSKU\u003c\/td\u003e\n\u003ctd\u003eZWO-OIII7NM1.25\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Type\u003c\/td\u003e\n\u003ctd\u003eOIII (Oxygen-III) Narrowband\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFormat\u003c\/td\u003e\n\u003ctd\u003eSingle Filter\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBandpass\u003c\/td\u003e\n\u003ctd\u003e7 nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSize\u003c\/td\u003e\n\u003ctd\u003e1.25\" (31.75mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMounting\u003c\/td\u003e\n\u003ctd\u003eThreaded Cell\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eShape\u003c\/td\u003e\n\u003ctd\u003eRound\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWarranty\u003c\/td\u003e\n\u003ctd\u003e2 Years\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\"\u003eZWO 1.25\" Mounted OIII 7nm 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 Plastic 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\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/zwo-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eZWO 2-Year Limited Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"ZWO","offers":[{"title":"1.25\" Round Mounted","offer_id":44967443726621,"sku":"ZWO-OIII7nm1.25","price":181.0,"currency_code":"CAD","in_stock":true},{"title":"2\" Round Mounted","offer_id":44967443759389,"sku":"ZWO-OIII7nm2","price":349.0,"currency_code":"CAD","in_stock":true},{"title":"36mm Round Unmounted","offer_id":44967443824925,"sku":"ZWO-OIII7nmD36","price":237.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/ZWO-OIII-Filter-1-25-inch__00574.1596920412.1280.1280.jpg?v=1684342099"},{"product_id":"zwo-narrowband-sii-filter-7nm","title":"ZWO Narrowband SII Filter - 7nm","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eIsolates the 672nm Sulfur-II emission line\u003c\/li\u003e\n\u003cli\u003e7nm bandpass for high-contrast imaging\u003c\/li\u003e\n\u003cli\u003eStandard 1.25\" threaded metal cell\u003c\/li\u003e\n\u003cli\u003e1\/4 wave polished substrate with multi-layer coatings\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\u003eDownloads\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\u003eZWO SII 7nm 1.25\" Narrowband Filter\u003c\/h2\u003e\n\u003cp\u003eThe ZWO SII 7nm 1.25\" Filter isolates the deep-red Sulfur-II emission line centered at 672nm, a critical wavelength for mapping ionized structure in emission nebulae. Its tight 7nm bandpass dramatically increases contrast by rejecting light pollution and moonlight, while the 1\/4 wave polished substrate ensures that the finest details are not lost to optical imperfections.\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\u003eIsolating Deep-Red Structure with a 7nm Bandpass\u003c\/h3\u003e\n\u003cp\u003eBy restricting transmission to a narrow 7nm window around the 672nm SII line, this filter renders the sky background nearly black, causing faint nebulosity to stand out with striking clarity. This high signal-to-noise ratio is essential for revealing the delicate, wispy structures in supernova remnants like the Veil Nebula (NGC 6960) or the intricate star-forming regions within the Eagle Nebula (M16).\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\/4 Wave Optics for High-Fidelity Imaging\u003c\/h3\u003e\n\u003cp\u003eEach ZWO narrowband filter is ground and polished to a 1\/4 wave surface accuracy, a specification that prevents distortion and maintains image sharpness across the field. Multiple layers of anti-reflection coatings are then applied to eliminate halos around bright stars and maximize light transmission within the 7nm bandpass, preserving the critical signal from your target.\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\u003eBuilding the Hubble Palette with the 1.25\" ZWO SII Filter\u003c\/h3\u003e\n\u003cp\u003eThis filter is the essential \"S\" component in the SHO color palette, made famous by images from the Hubble Space Telescope. When you combine data captured through this SII filter with separate exposures using Hydrogen-alpha and Oxygen-III filters, you can create stunning, scientifically valuable images that map the chemical composition of nebulae in vibrant gold, cyan, and blue hues. The standard 1.25\" threaded cell ensures compatibility with most filter wheels and camera nosepieces.\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 purpose of the ZWO 7nm SII filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe ZWO 7nm SII filter is a narrowband filter designed for astrophotography with monochrome cameras. It isolates the 672nm wavelength of light emitted by ionized sulfur, which is crucial for capturing specific structural details in emission nebulae and creating \"Hubble Palette\" (SHO) images.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the ZWO 7nm SII filter with a color camera?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWhile technically possible, it is not recommended. Color cameras have a Bayer matrix (RGB filters) over their sensors, and only the red pixels will receive signal from the 672nm SII line. This results in a significant loss of signal and resolution, making a monochrome camera the superior choice for narrowband imaging.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the ZWO 7nm SII filter perform on the Rosette Nebula (NGC 2237) with a monochrome camera?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eOn a target like the Rosette Nebula, the ZWO 7nm SII filter excels at revealing the shock fronts and ionization structures that are less prominent in Hydrogen-alpha. It isolates the outer shell and filamentary details, providing the essential \"S\" channel data that adds depth and a golden hue to a final SHO composite image.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat exposure times should I expect for the ZWO 7nm SII filter with an 8\" f\/4 Newtonian?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWith a fast f\/4 system, you can typically start with exposures of 300 to 600 seconds per sub-frame from a moderately light-polluted (Bortle 4-5) site. Sulfur-II is often the faintest of the three main narrowband channels (Ha, OIII, SII), so you may need to expose 1.5x to 2x longer for SII than you do for Hydrogen-alpha to achieve a comparable signal level.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhy is a 7nm bandpass important for the ZWO SII filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eA narrower bandpass is more effective at rejecting unwanted light, such as from city glow, moonlight, and natural skyglow. The \u003cstrong\u003e7nm\u003c\/strong\u003e bandpass provides a very high-contrast view by darkening the sky background significantly, making it superior to wider 12nm or 15nm filters, especially from suburban locations.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill the ZWO 7nm SII filter thread into a standard 1.25\" filter wheel?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The ZWO 7nm SII filter is mounted in a standard 1.25\" metal cell with M28.5x0.6 threads. It is fully compatible with any 1.25\" filter wheel, filter drawer, or accessory that accepts standard 1.25\" threaded filters.\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\u003eSKU\u003c\/td\u003e\n\u003ctd\u003eZWO-SII7NM1.25\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Type\u003c\/td\u003e\n\u003ctd\u003eSulfur-II (SII) Narrowband\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBandwidth\u003c\/td\u003e\n\u003ctd\u003e7 nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSize\u003c\/td\u003e\n\u003ctd\u003e31.75mm (1.25\")\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMount Style\u003c\/td\u003e\n\u003ctd\u003eThreaded Cell\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eShape\u003c\/td\u003e\n\u003ctd\u003eRound\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCategory\u003c\/td\u003e\n\u003ctd\u003eSingle Filter\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\" Mounted Sulfur II 7nm 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 Plastic 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\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/www.zwoastro.com\/software\/\" target=\"_blank\"\u003e\u003csvg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewbox=\"0 0 640 512\" class=\"DAV-img-box\"\u003e\u003cpath fill=\"#0047a7\" d=\"M128 32C92.7 32 64 60.7 64 96l0 256 64 0 0-256 384 0 0 256 64 0 0-256c0-35.3-28.7-64-64-64L128 32zM19.2 384C8.6 384 0 392.6 0 403.2C0 445.6 34.4 480 76.8 480l486.4 0c42.4 0 76.8-34.4 76.8-76.8c0-10.6-8.6-19.2-19.2-19.2L19.2 384z\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDownload Software\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/zwo-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eZWO 2-Year Limited Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"ZWO","offers":[{"title":"1.25\" Round Mounted","offer_id":44967443857693,"sku":"ZWO-SII7nm1.25","price":181.0,"currency_code":"CAD","in_stock":true},{"title":"2\" Round Mounted","offer_id":44967443890461,"sku":"ZWO-SII7nm2","price":349.0,"currency_code":"CAD","in_stock":true},{"title":"36mm Round Unmounted","offer_id":44967443955997,"sku":"ZWO-SII7nmD36","price":237.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/ZWO-SII-Filter-1-25-inch__61822.1596920329.1280.1280.jpg?v=1684342114"},{"product_id":"zwo-uv-ir-cut-filter","title":"ZWO UV\/IR CUT Filter","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eThreads into standard 1.25\" filter holders and nosepieces\u003c\/li\u003e\n\u003cli\u003eBlocks unwanted ultraviolet (UV) and infrared (IR) wavelengths\u003c\/li\u003e\n\u003cli\u003eFunctions as a primary Luminance (L) filter for LRGB imaging\u003c\/li\u003e\n\u003cli\u003eEssential for achieving sharp focus with color CMOS and CCD cameras\u003c\/li\u003e\n\u003cli\u003eIncludes a protective plastic storage case\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\u003eDownloads\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\u003eZWO 1.25\" IR Cut-Off Filter\u003c\/h2\u003e\n\u003cp\u003eThe ZWO 1.25\" IR Cut-Off Filter is an essential component for any color astrocamera, threading directly into a standard 31.75mm nosepiece or filter wheel. This single filter, backed by a 2-Year ZWO warranty, corrects for bloated stars and loss of detail by blocking the unfocused infrared light your sensor sees but your eye cannot.\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\u003eRestoring Image Sharpness at 1.25\"\u003c\/h3\u003e\n\u003cp\u003eA silicon camera sensor's sensitivity extends far beyond what the human eye can see, deep into the infrared (IR) spectrum. While your telescope's optics are designed to bring visible light to a sharp focus, they do not focus IR light at the same point. This mismatch results in a sharp visual image being overlaid with a soft, blurry IR image, causing fuzzy details and bloated stars. The ZWO 1.25\" UV\/IR Cut filter solves this by completely blocking these unwanted wavelengths, restoring the sharpness your optics are capable of delivering.\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\u003eEssential IR Protection for 31.75mm Imaging Systems\u003c\/h3\u003e\n\u003cp\u003eThis filter serves a critical dual role in any astrophotography setup. For any one-shot-color camera, it is the primary defense against IR contamination and is necessary for accurate color and sharp focus. For monochrome imagers, this filter is your Luminance (L) channel in an LRGB filter set, capturing all the detail of the visible spectrum.\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\"\u003eWill the ZWO 1.25\" UV\/IR Cut filter improve my images of Jupiter with a ZWO ASI224MC camera?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, absolutely. Planetary imaging relies on capturing the finest possible details. Since your camera is highly sensitive to IR light that your telescope doesn't focus sharply, this filter removes the resulting blur, leading to much sharper views of Jupiter's cloud bands and the Great Red Spot.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDo I need the ZWO 1.25\" UV\/IR Cut filter for deep-sky imaging of the Andromeda Galaxy (M31) with my color camera?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. While the effect can be more subtle than on planets, it is still essential for high-quality deep-sky images. The filter tightens star sizes across the entire frame and improves the final sharpness of dust lanes and galactic structure by eliminating the soft, unfocused IR signal that would otherwise wash out fine detail.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the difference between this ZWO UV\/IR Cut filter and a Luminance filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eFor most astrophotography applications, they are functionally the same. A \u003cstrong\u003eLuminance (L) filter's\u003c\/strong\u003e primary job is to pass the entire visible spectrum while blocking ultraviolet (UV) and infrared (IR) light. This ZWO 1.25\" UV\/IR Cut filter serves that exact purpose, making it the correct choice for the L-filter in an LRGB imaging sequence.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eMy camera has an AR window. Do I still need the ZWO 1.25\" UV\/IR Cut filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. An \u003cstrong\u003eAnti-Reflection (AR)\u003c\/strong\u003e window is designed only to maximize light transmission and prevent internal reflections. It does \u003cstrong\u003enot\u003c\/strong\u003e block IR wavelengths. You still need a separate UV\/IR Cut filter to prevent IR bloat and achieve a sharp image.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the ZWO 1.25\" UV\/IR Cut filter for visual observing?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYou can, but you will not notice any difference in the view. The human eye is not sensitive to the infrared light this filter blocks. Its image-sharpening effect is only apparent when using a silicon-based camera sensor.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow do I attach the ZWO 1.25\" UV\/IR Cut filter to my camera?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe filter is housed in a standard 1.25\" threaded cell. You can screw it directly onto the 1.25\" nosepiece of your astronomy camera or into a dedicated slot in a 1.25\" filter wheel.\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\u003eSKU\u003c\/td\u003e\n\u003ctd\u003eZWO-IRCUT1.25\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Class\u003c\/td\u003e\n\u003ctd\u003eSingle Filter\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Type\u003c\/td\u003e\n\u003ctd\u003eUV\/IR Cut \/ Luminance\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSize\u003c\/td\u003e\n\u003ctd\u003e1.25\" (31.75mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eShape\u003c\/td\u003e\n\u003ctd\u003eRound\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMounting\u003c\/td\u003e\n\u003ctd\u003eThreaded Cell\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWarranty\u003c\/td\u003e\n\u003ctd\u003e2 Years\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\"\u003eZWO IR-Blocking Filter in 1.25\" Cell\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\"\u003ePlastic Filter 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\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/www.zwoastro.com\/software\/\" target=\"_blank\"\u003e\u003csvg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewbox=\"0 0 640 512\" class=\"DAV-img-box\"\u003e\u003cpath fill=\"#0047a7\" d=\"M128 32C92.7 32 64 60.7 64 96l0 256 64 0 0-256 384 0 0 256 64 0 0-256c0-35.3-28.7-64-64-64L128 32zM19.2 384C8.6 384 0 392.6 0 403.2C0 445.6 34.4 480 76.8 480l486.4 0c42.4 0 76.8-34.4 76.8-76.8c0-10.6-8.6-19.2-19.2-19.2L19.2 384z\"\u003e\u003c\/path\u003e\u003c\/svg\u003e \n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDownload Software\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"https:\/\/davidastro.com\/pages\/zwo-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eZWO 2-Year Limited Warranty\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"ZWO","offers":[{"title":"1.25\" Round Mounted","offer_id":44967447920925,"sku":"ZWO-IRCUT1.25","price":40.0,"currency_code":"CAD","in_stock":true},{"title":"2\" Round Mounted","offer_id":44967447953693,"sku":"ZWO-IRCUT2","price":69.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/ZWO-UV-IR-CUT-Filter-1-25-inch-1__13605.1596910062.1280.1280.jpg?v=1684342154"},{"product_id":"zwo-duo-band-filter","title":"ZWO Duo-Band Filter","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003ePasses H-Alpha (15nm) and OIII (35nm) Wavelengths\u003c\/li\u003e\n\u003cli\u003eDesigned for One-Shot Color (OSC) Cameras\u003c\/li\u003e\n\u003cli\u003e1.25\" Threaded Cell\u003c\/li\u003e\n\u003cli\u003eOver 80% Ha \u0026amp; 90% OIII Transmission\u003c\/li\u003e\n\u003cli\u003e1\/4 Wavefront Polished Substrate\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\u003eDownloads\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\u003eZWO 1.25\" Duo-Band Filter\u003c\/h2\u003e\n\u003cp\u003eThe ZWO 1.25\" Duo-Band Filter makes narrowband imaging possible for color cameras by isolating the two most critical emission nebula wavelengths. It captures H-Alpha (656.3 nm) in a 15 nm bandpass and OIII (500 nm) in a 35 nm bandpass, with transmission rates exceeding 80% and 90% respectively. This dual-band approach dramatically increases contrast on emission targets, allowing you to capture clean, detailed data from light-polluted locations with your existing one-shot color camera.\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\u003eCapture Narrowband Data with Your OSC Camera at Over 90% Transmission\u003c\/h3\u003e\n\u003cp\u003eThis filter is the most direct path to narrowband imaging for any astronomer with a color CMOS or CCD camera. By simultaneously passing both the deep red of Hydrogen-alpha and the teal-blue of Oxygen-III, it collects the primary structural and detail wavelengths of emission nebulae in a single exposure. This eliminates the need for a monochrome camera, filter wheel, and separate SHO filter set, significantly simplifying your imaging train and reducing total acquisition time.\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\u003e15nm Ha \u0026amp; 35nm OIII Bandpasses Optimized for Signal\u003c\/h3\u003e\n\u003cp\u003eThe ZWO Duo-Band filter features a 15 nm bandpass for H-Alpha and a wider 35 nm bandpass for OIII. This design is a deliberate trade-off, balancing interference rejection with the signal requirements of a color sensor's Bayer matrix. These wider-than-typical bandpasses allow more photons to reach the sensor, which is critical for achieving a strong signal-to-noise ratio with an OSC camera in reasonable exposure times, while still blocking the vast majority of light pollution from city lights 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\u003eZWO Duo-Band Filter vs. A Full Monochrome Setup\u003c\/h3\u003e\n\u003cp\u003eA dedicated monochrome camera with a filter wheel and 3nm or 5nm narrowband filters will always provide the highest possible resolution and data separation. That setup allows for precise control over each channel for complex Hubble Palette (SHO) processing. However, the ZWO Duo-Band Filter with a color camera grants access to high-contrast nebula imaging at a fraction of the cost, complexity, and setup time. For imagers in light-polluted skies who want to capture stunning nebulae without investing in a second complete imaging system, the Duo-Band filter is the more pragmatic solution.\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\/4 Wavefront Optics \u0026amp; Anti-Reflection Build\u003c\/h3\u003e\n\u003cp\u003eEach Duo-Band filter is built on a Schott substrate, polished to a 1\/4 wavefront accuracy to ensure your telescope's resolution is not compromised. The 60\/40 surface quality meets MIL-O-13830 standards, and the filter cell itself is CNC machined from aircraft-grade aluminum. An anodized finish and internal extinction treatments prevent reflections and internal glare from degrading your final image, preserving the high contrast this filter is designed to create.\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\"\u003eHow will the ZWO Duo-Band Filter perform on the Orion Nebula (M42) with a color camera?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe ZWO Duo-Band filter is excellent for the Orion Nebula (M42). It will isolate the rich Hydrogen-alpha signal in the outer wings and the strong Oxygen-III emission in the Trapezium core. From a light-polluted site, this filter will dramatically darken the sky background, making the nebula's structure and color far more prominent than with a standard light pollution filter.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I image galaxies like Andromeda (M31) with the ZWO Duo-Band Filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, this filter is not recommended for broadband targets like galaxies or star clusters. Galaxies emit light across the entire visible spectrum. The Duo-Band filter blocks almost all of that light, passing only the H-alpha and OIII wavelengths. While you would capture the small emission nebulae within M31's arms, the galaxy's core and dust lanes would be almost completely filtered out. Use a broadband light pollution filter for galaxies.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhy are the H-Alpha (15nm) and OIII (35nm) bandpasses different widths on the ZWO Duo-Band Filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe different bandpass widths are an intentional design choice for use with one-shot color cameras. The wider \u003cstrong\u003e35 nm OIII bandpass\u003c\/strong\u003e allows more signal to pass through the Bayer matrix of the sensor, which is less sensitive to these wavelengths. The tighter \u003cstrong\u003e15 nm Ha bandpass\u003c\/strong\u003e provides higher contrast on the stronger hydrogen signal, balancing signal strength with rejection of nearby light pollution sources.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the ZWO Duo-Band Filter a good replacement for a monochrome camera setup?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eIt is an excellent alternative, but not a direct replacement. A monochrome camera with separate, very narrowband (e.g., 3nm) filters offers superior data isolation for advanced processing techniques like the Hubble Palette. The ZWO Duo-Band Filter provides a much simpler and more affordable way for OSC camera users to achieve the high-contrast results of narrowband imaging on emission nebulae, without the cost and complexity of a full mono system.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill the 1.25\" ZWO Duo-Band filter work in my ZWO EFW filter wheel?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, the ZWO 1.25\" Duo-Band Filter is threaded to mount directly into any ZWO electronic filter wheel (EFW) that accepts 1.25\" filters. It can also be threaded directly onto any 1.25\" nosepiece or accessory with standard filter threads.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat does the 60\/40 surface quality specification mean for the ZWO Duo-Band Filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThis specification refers to the optical polish and surface imperfections based on the MIL-O-13830 military standard. The \"60\" is the scratch designation, nominally corresponding to a scratch width of about 6 microns, and the \"40\" refers to the maximum allowable dig or pit diameter in hundredths of a millimeter. A 60\/40 rating indicates a high-quality optical surface suitable for demanding imaging applications, ensuring minimal light scatter and preserved image contrast.\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\u003eSKU\u003c\/td\u003e\n\u003ctd\u003eZWO-DB1.25\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Type\u003c\/td\u003e\n\u003ctd\u003eDual Narrowband Pass (Ha, OIII)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSize\u003c\/td\u003e\n\u003ctd\u003e1.25\" (31.75mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMounting\u003c\/td\u003e\n\u003ctd\u003eThreaded Cell\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eH-Alpha Bandpass\u003c\/td\u003e\n\u003ctd\u003e15 nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOIII Bandpass\u003c\/td\u003e\n\u003ctd\u003e35 nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eH-Alpha Transmission\u003c\/td\u003e\n\u003ctd\u003e\u0026gt;80% at 656.3 nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOIII Transmission\u003c\/td\u003e\n\u003ctd\u003e\u0026gt;90% at 495.9 nm and 500.7 nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWavefront Accuracy\u003c\/td\u003e\n\u003ctd\u003e1\/4 Wavefront\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSubstrate\u003c\/td\u003e\n\u003ctd\u003eSchott Glass\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eThickness\u003c\/td\u003e\n\u003ctd\u003e1.85 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSurface Quality\u003c\/td\u003e\n\u003ctd\u003e60\/40 (per MIL-O-13830)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eShape\u003c\/td\u003e\n\u003ctd\u003eRound\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\"\u003eZWO 1.25\" Duo-Band Filter\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\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/www.zwoastro.com\/software\/\" target=\"_blank\"\u003e\u003csvg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewbox=\"0 0 640 512\" class=\"DAV-img-box\"\u003e\u003cpath fill=\"#0047a7\" d=\"M128 32C92.7 32 64 60.7 64 96l0 256 64 0 0-256 384 0 0 256 64 0 0-256c0-35.3-28.7-64-64-64L128 32zM19.2 384C8.6 384 0 392.6 0 403.2C0 445.6 34.4 480 76.8 480l486.4 0c42.4 0 76.8-34.4 76.8-76.8c0-10.6-8.6-19.2-19.2-19.2L19.2 384z\"\u003e\u003c\/path\u003e\u003c\/svg\u003e \n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDownload Software\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/zwo-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eZWO 2-Year Limited Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"ZWO","offers":[{"title":"1.25\" Round Mounted","offer_id":44967448379677,"sku":"ZWO-DB1.25","price":139.0,"currency_code":"CAD","in_stock":true},{"title":"2\" Round Mounted","offer_id":44967448412445,"sku":"ZWO-DB2","price":239.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/ZWO-Duo-Band-Filter-1__12335.1596910054.1280.1280.jpg?v=1684342173"},{"product_id":"zwo-ar-protective-window","title":"ZWO AR Protective Window","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eProtects camera sensor from dust and humidity\u003c\/li\u003e\n\u003cli\u003e21mm diameter for specific ZWO camera models\u003c\/li\u003e\n\u003cli\u003eHigh-transmission Anti-Reflection (AR) coatings\u003c\/li\u003e\n\u003cli\u003e1\/4λ surface flatness prevents image degradation\u003c\/li\u003e\n\u003cli\u003e1.1mm thickness ensures no change to back focus\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\u003eZWO D21 AR Protective Window\u003c\/h2\u003e\n\u003cp\u003eThe ZWO D21 AR Window provides essential sensor protection with an optically precise 1\/4λ surface flatness to maintain image sharpness. Its 21mm diameter and slim 1.1mm thickness ensure a perfect fit in compatible ZWO cameras, using high-transmission anti-reflection coatings to shield the sensor from dust and moisture without altering the optical path.\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\u003eTransparent Protection at 1\/4λ Flatness\u003c\/h3\u003e\n\u003cp\u003eThis window serves as a clear, protective barrier between your camera's delicate sensor and the outside environment. The 1\/4λ surface flatness specification guarantees the window's surfaces are optically flat, preventing it from introducing any distortion, astigmatism, or other aberrations into your images. It is an insurance policy for your sensor that has no detectable impact on optical quality.\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\u003eSeamless Fit with a 21mm Diameter\u003c\/h3\u003e\n\u003cp\u003eDesigned as a direct replacement or protective addition, the 21mm diameter window fits a wide range of popular ZWO cameras, including the ASI120, ASI224, ASI290, ASI178, and ASI385 series. This precise sizing ensures it seats correctly within the camera body, providing a complete seal against contaminants.\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\u003eMinimal Optical Impact at 1.1mm Thickness\u003c\/h3\u003e\n\u003cp\u003eAt just 1.1mm thick and featuring anti-reflection (AR) coatings on both surfaces, this window is engineered to be nearly invisible to your telescope's light path. The AR coatings maximize light transmission and eliminate ghosting from bright stars. The 1.1mm thickness matches original factory windows, ensuring you maintain the correct back focus without needing additional spacers or adjustments.\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 purpose of the ZWO D21 AR Window?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eIt acts as a protective cover for your camera's sensor. It shields the delicate sensor from dust, humidity, and potential physical contact without degrading image quality, thanks to its 1\/4λ flatness and AR coatings.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhich ZWO cameras use the D21 AR Window?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe D21 AR window is compatible with several ZWO cameras, including the \u003cstrong\u003eASI120MM\/MM-S, ASI224MC, ASI385MC, ASI290MC\/MM, ASI290MINI, ASI178MM, and ASI120MINI\u003c\/strong\u003e models. Always confirm your specific camera model before purchasing.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill installing the D21 AR Window change my focus point?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo. With a thickness of just 1.1mm, it is designed to be optically neutral and match the original window in compatible cameras. Your focus point and back focus should remain unchanged.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow do I install the ZWO D21 AR Window on my ASI290MM Mini?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eInstallation involves carefully unscrewing the front nosepiece of the camera to access the sensor chamber. The old window (if present) can be gently removed, and the new D21 AR window is dropped into its place. Ensure the environment is as dust-free as possible during the process.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the D21 AR Window instead of a UV\/IR cut filter for planetary imaging with my ASI224MC?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, this is not a filter. The D21 is an AR-coated clear window designed for protection and maximum light transmission. For planetary imaging with a color camera like the ASI224MC, you still need a separate \u003cstrong\u003eUV\/IR Cut (Luminance) filter\u003c\/strong\u003e to ensure correct color balance and sharpness, as the sensor is sensitive to out-of-band light.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow should I clean the ZWO D21 AR Window?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eTreat it like any high-quality optic. First, use a clean air blower to remove any loose dust. For fingerprints or smudges, use a microfiber cloth with a small amount of a dedicated optical cleaning solution. Wipe gently in a circular motion from the center outwards to avoid scratching the AR coatings.\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\u003eSKU\u003c\/td\u003e\n\u003ctd\u003eZWO-D21AR1\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDiameter\u003c\/td\u003e\n\u003ctd\u003e21 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eThickness\u003c\/td\u003e\n\u003ctd\u003e1.1 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSurface Flatness\u003c\/td\u003e\n\u003ctd\u003e1\/4 λ\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eType\u003c\/td\u003e\n\u003ctd\u003eAR Coated Protective Window\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\"\u003eD21 AR Window\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\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/zwo-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eZWO 2-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"ZWO","offers":[{"title":"21mm","offer_id":44967448609053,"sku":"ZWO-D21AR","price":26.0,"currency_code":"CAD","in_stock":true},{"title":"25mm","offer_id":44967448641821,"sku":"ZWO-D25AR","price":26.0,"currency_code":"CAD","in_stock":true},{"title":"60mm","offer_id":44967448674589,"sku":"ZWO-D60AR","price":69.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/ZWO-Protective-Window-1__97293.1596910060.1280.1280.jpg?v=1684342186"},{"product_id":"zwo-ir-cut-protective-window","title":"ZWO IR-Cut Protective Window","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e21 mm diameter protective window for select ZWO cameras\u003c\/li\u003e\n\u003cli\u003eIntegrated UV\/IR-Cut filter maintains natural color balance\u003c\/li\u003e\n\u003cli\u003e1\/4 λ surface flatness preserves image sharpness\u003c\/li\u003e\n\u003cli\u003e1.1 mm thickness for correct optical path length\u003c\/li\u003e\n\u003cli\u003eSeals sensor chamber from dust and humidity\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\u003eDownloads\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\u003eZWO D21 IR-Cut Window\u003c\/h2\u003e\n\u003cp\u003eThe ZWO D21 IR-Cut Window is a precision-polished optical element designed to protect your camera's sensor, featuring a 21 mm diameter and a standard 1.1 mm thickness. Its integrated UV\/IR-Cut filter preserves true color balance, while the 1\/4 λ surface flatness ensures that the window does not introduce any degradation to your final image sharpness.\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\u003ePrecision Optics: 1\/4 λ Flatness at 1.1 mm Thickness\u003c\/h3\u003e\n\u003cp\u003eThis is not simply a piece of glass; it is a critical optical component. The ZWO D21 window is ground and polished to a 1\/4 λ surface flatness, a specification that guarantees it is optically transparent and will not distort the incoming wavefront from your telescope. This preserves the finest details on planetary surfaces and ensures tight, point-like stars. The 1.1 mm thickness is standard for ZWO cameras, ensuring no change in back focus when replacing a stock window.\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\u003eOEM Protection: 21 mm Diameter with UV\/IR-Cut\u003c\/h3\u003e\n\u003cp\u003eDesigned as a direct factory replacement, the 21 mm diameter window perfectly seals the sensor chamber of compatible ZWO cameras from dust, pollen, and humidity. The integrated UV\/IR-Cut coating is essential for all color cameras, as it blocks the out-of-focus infrared and ultraviolet wavelengths that CMOS sensors are highly sensitive to. This prevents star bloat and delivers a clean, color-accurate image without requiring a separate filter.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eDirect Fit:\u003c\/strong\u003e Replaces the original window on the ASI120MC-S and ASI178MC cameras.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEssential Filtration:\u003c\/strong\u003e Acts as the built-in IR-cut filter for color cameras, correcting for the sensor's infrared sensitivity to produce natural colors on targets like Jupiter's Great Red Spot and Mars' polar caps.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSensor Safety:\u003c\/strong\u003e Provides a physical barrier that protects the delicate CMOS sensor and its microlenses from physical contact and environmental contaminants.\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\"\u003eWhich ZWO cameras are compatible with the D21 IR-Cut Window?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe ZWO D21 IR-Cut Window is a direct replacement for the stock window on the following camera series: \u003cstrong\u003eASI120MC-S and ASI178MC.\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhy is 1\/4 λ flatness important for the ZWO D21 window?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eA \u003cstrong\u003e1\/4 λ (quarter-wave) flatness\u003c\/strong\u003e specification ensures the window is optically perfect and will not bend or distort light as it passes through to the sensor. A less flat window would act like a poor-quality lens, softening the image and reducing the fine detail your telescope resolves. This precision is critical for high-resolution planetary, lunar, and solar imaging.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the ZWO D21 IR-Cut Window required for monochrome cameras?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo. ZWO lists the D21 IR-Cut Window only for the color ASI120MC-S and ASI178MC. Monochrome cameras like the ASI290MM or ASI178MM use the D21 AR window, which protects the sensor from dust and humidity without blocking IR.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIf I see dust spots on my ASI224MC images, do I need to replace this window?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNot necessarily. The first step is to try cleaning the exterior surface of the window with a sensor cleaning kit or rocket blower. If the dust motes remain fixed in the same position on your flat frames after cleaning, they are likely on the sensor itself, which may require removing the window for a deeper cleaning. You would only replace the window if it is scratched, cracked, or the coatings are degraded.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill using the ZWO D21 IR-Cut Window affect my focus when imaging the Moon with my ASI2600MC Pro?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, it will not affect your focus. The ZWO D21 is designed to be parfocal with the original window installed in the camera from the factory. At 1.1 mm thick, it maintains the correct optical path length, so you can replace a damaged window without needing to change your focuser position.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow do I know if my ZWO camera's protective window is damaged?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eDamage can be physical or a degradation of the coatings. Look for obvious scratches or cracks. Coating failure can appear as blotchy or hazy patterns on the glass that cannot be cleaned off. These issues will show up in your images as fixed artifacts or a general loss of contrast that cannot be corrected with flat frames.\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\u003eSKU\u003c\/td\u003e\n\u003ctd\u003eZWO-D21IR-CUT1\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDiameter\u003c\/td\u003e\n\u003ctd\u003e21 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Type\u003c\/td\u003e\n\u003ctd\u003eUV\/IR-Cut Protective Window\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eThickness\u003c\/td\u003e\n\u003ctd\u003e1.1 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSurface Flatness\u003c\/td\u003e\n\u003ctd\u003e1\/4 λ\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWarranty\u003c\/td\u003e\n\u003ctd\u003e2 Years\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\"\u003eD21 IR-Cut Window\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\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/www.zwoastro.com\/software\/\" target=\"_blank\"\u003e\u003csvg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewbox=\"0 0 640 512\" class=\"DAV-img-box\"\u003e\u003cpath fill=\"#0047a7\" d=\"M128 32C92.7 32 64 60.7 64 96l0 256 64 0 0-256 384 0 0 256 64 0 0-256c0-35.3-28.7-64-64-64L128 32zM19.2 384C8.6 384 0 392.6 0 403.2C0 445.6 34.4 480 76.8 480l486.4 0c42.4 0 76.8-34.4 76.8-76.8c0-10.6-8.6-19.2-19.2-19.2L19.2 384z\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDownload Software\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"https:\/\/davidastro.com\/pages\/zwo-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eZWO 2-Year Limited Warranty\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"ZWO","offers":[{"title":"21mm","offer_id":44967449723165,"sku":"ZWO-D21IR-CUT1","price":26.0,"currency_code":"CAD","in_stock":true},{"title":"25mm","offer_id":44967449755933,"sku":"ZWO-D25IR-CUT1","price":26.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/ZWO-Protective-Window-1__97293.1596910060.1280.1280__39733.1596912514.1280.1280.jpg?v=1684342198"}],"url":"https:\/\/davidastro.com\/en-us\/collections\/zwo-filters.oembed","provider":"David Astro","version":"1.0","type":"link"}