{"product_id":"pegasus-astro-2inch-mounted-photographic-filter-green","title":"Pegasus Astro 2inch mounted photographic filter - Green","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e2-inch mounted LRGB Green filter\u003c\/li\u003e\n\u003cli\u003eTransmission \u0026gt;95% from 500-550nm\u003c\/li\u003e\n\u003cli\u003eParfocal design requires no refocusing between filters\u003c\/li\u003e\n\u003cli\u003e1\/4 wavefront polished glass preserves image sharpness\u003c\/li\u003e\n\u003cli\u003eMultilayer anti-reflection coatings reduce halos\u003c\/li\u003e\n\u003cli\u003eStandard M48 x 0.75 filter threads\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\u003e2-inch Mounted LRGB Green Filter\u003c\/h2\u003e\n\u003cp\u003eThis 2-inch mounted photographic green filter isolates a specific 500-550nm wavelength range, delivering over 95% average transmission for the green channel in LRGB deep-sky imaging. The 1\/4 wavefront polished glass is parfocal with other filters in its series, ensuring that you can switch between channels without losing focus. Standard M48 x 0.75 threads allow for easy integration into any 2-inch filter wheel or accessory train.\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\u003eGreen Channel Isolation: \u0026gt;95% Transmission from 500-550nm\u003c\/h3\u003e\n\u003cp\u003eEngineered as a high-performance bandpass filter, this filter targets the core green portion of the visible spectrum. By transmitting a narrow 500-550nm window with an average efficiency greater than 95%, it captures clean, high-signal data for the \"G\" component of your color images while aggressively rejecting light pollution and other unwanted wavelengths. This precise isolation is critical for building a final LRGB image with natural star colors and well-defined nebulosity.\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 Parfocal Construction\u003c\/h3\u003e\n\u003cp\u003eTo ensure the filter does not degrade your telescope's optical resolution, the 2mm thick glass is polished to a 1\/4 wavefront standard. The filter is also designed to be parfocal, meaning you can swap between your L, R, G, and B filters without adjusting your focuser. This saves critical time during an imaging session and eliminates the risk of focus shift between exposures, resulting in consistently sharper final images.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMultilayer Anti-Reflection Coatings:\u003c\/strong\u003e Applied to both surfaces to minimize halos, internal reflections, and ghosting on bright stars.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eM48 x 0.75 Threads:\u003c\/strong\u003e The industry-standard threading for 2-inch filters ensures compatibility with virtually all filter wheels, drawers, and camera nosepieces.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDurable Cell:\u003c\/strong\u003e The 2mm thick glass is housed in a robust metal cell with a total thickness of 5mm, providing durability and secure handling.\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 this 2-inch Green filter primarily used for?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThis is a monochrome imaging filter designed to capture the green light component for creating a full-color LRGB (Luminance, Red, Green, Blue) image. You would take separate exposures with this filter, a red filter, a blue filter, and a luminance filter, then combine them in post-processing to create a final color photograph.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill I need to refocus my telescope when switching to this Green filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo. This filter is \u003cstrong\u003eparfocal\u003c\/strong\u003e, meaning it is manufactured to the same optical thickness as the other filters in its set (Red, Blue, and Luminance). This allows you to switch between them without needing to adjust your focuser, maintaining sharp stars across all your color channels.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the 500-550nm transmission of this Green filter help when imaging a galaxy like Andromeda (M31)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe 500-550nm range captures the green light from star-forming regions and the integrated light from billions of stars in the galaxy's core and spiral arms. By isolating this specific band with \u0026gt;95% transmission, the filter provides a high-signal, low-noise green channel, which is essential for rendering the natural colors of M31 when combined with Red and Blue data.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIf I'm using an f\/8 refractor, will the 1\/4 wavefront polish on this Green filter make a difference?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. A 1\/4 wavefront polish ensures the filter will not introduce any significant optical errors that could soften the image from your telescope. Maintaining the quality of the incoming wavefront is crucial for achieving the sharpest possible stars and finest details, regardless of your telescope's focal ratio.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat do the M48 x 0.75 threads on this 2-inch Green filter mean?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThis is the standard thread size for 2-inch astronomy filters. The \"M48\" refers to the 48mm diameter, and \"0.75\" is the thread pitch in millimeters. This ensures the filter will screw directly into any 2-inch filter wheel, filter drawer, or camera nosepiece designed for this common format.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDo the anti-reflection coatings on this Green filter help reduce halos?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eAbsolutely. The multilayer anti-reflection coatings are specifically designed to minimize reflections between the filter surfaces, your camera sensor, and other optical elements. This significantly reduces the size and intensity of halos and ghosting artifacts around bright stars like Vega or Sirius.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Size\u003c\/td\u003e\n\u003ctd\u003e2 inch\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Type\u003c\/td\u003e\n\u003ctd\u003eBandpass (LRGB Green)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTransmission Band\u003c\/td\u003e\n\u003ctd\u003e500-550nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePeak Transmission\u003c\/td\u003e\n\u003ctd\u003e\u0026gt;95% (average)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOptical Polish\u003c\/td\u003e\n\u003ctd\u003e1\/4 wavefront\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eParfocal\u003c\/td\u003e\n\u003ctd\u003eYes\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCoatings\u003c\/td\u003e\n\u003ctd\u003eMultilayer Anti-reflection\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eThreads\u003c\/td\u003e\n\u003ctd\u003eM48 x 0.75\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eGlass Thickness\u003c\/td\u003e\n\u003ctd\u003e2mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTotal Cell Thickness\u003c\/td\u003e\n\u003ctd\u003e5mm (filter) + 2.5mm (thread)\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\"\u003e2-inch Mounted LRGB 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\"\u003eProtective Storage Case\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"https:\/\/davidastro.com\/pages\/pegasus-astro-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003ePegasus Astro 2-Year Warranty\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Pegasus Astro","offers":[{"title":"Default Title","offer_id":52686359822621,"sku":"PEG-FLTR-2M-G","price":84.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/pegasus-astro-2inch-mounted-photographic-filter-green-1_334fbc10-4b7e-425a-8946-1862e896e505.png?v=1793650767","url":"https:\/\/davidastro.com\/fr-us\/products\/pegasus-astro-2inch-mounted-photographic-filter-green","provider":"David Astro","version":"1.0","type":"link"}