{"product_id":"used-hutech-idas-ngs1-light-pollution-filter-2","title":"Used Hutech IDAS NGS1 Night Glow Suppression Filter - 2\"","description":"\u003cp\u003eThis is a 2\" Hutech IDAS Night Glow Suppression Pollution filter in very good condition. The optics have a small amount of dust on the back side that we have not been able to remove; see the photos.  We have reduced the price accordingly to account for this condition issue. \u003cmeta charset=\"utf-8\"\u003eThis includes the jewel case. \u003c\/p\u003e\n\u003cp\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003ch4\u003eDescription:\u003c\/h4\u003e\n\u003cdiv class=\"specs-table\"\u003e\n\u003cmeta charset=\"utf-8\"\u003e\n\u003cmeta charset=\"UTF-8\"\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"specs-table\"\u003e\u003c\/div\u003e\n\u003cdiv class=\"specs-table\"\u003e\n\u003ca data-encoded-attr-charset=\"dXRmLTg=\" data-encoded-tag-value=\"\" data-encoded-tag-name=\"meta\"\u003e\u003c\/a\u003e\u003cimg src=\"https:\/\/agenaastro.com\/media\/opti_image\/webp\/catalog\/product\/cache\/74c1057f7991b4edb2bc7bdaa94de933\/n\/g\/ngs1.webp\" alt='IDAS Night Glow Supression Filter - 2\" Mounted # NGS1-48ST2'\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"specs-table\"\u003e\n\u003ca data-encoded-attr-charset=\"dXRmLTg=\" data-encoded-tag-value=\"\" data-encoded-tag-name=\"meta\"\u003e\u003c\/a\u003e\n\u003cdiv class=\"prose\"\u003e\n\u003cdiv data-content-type=\"row\" data-appearance=\"contained\" data-element=\"main\"\u003e\n\u003cdiv data-enable-parallax=\"0\" data-parallax-speed=\"0.5\" data-background-images=\"{}\" data-background-type=\"image\" data-video-loop=\"true\" data-video-play-only-visible=\"true\" data-video-lazy-load=\"true\" data-video-fallback-src=\"\" data-element=\"inner\" data-pb-style=\"LTK5X6I\"\u003e\n\u003cdiv data-content-type=\"text\" data-appearance=\"default\" data-element=\"main\"\u003e\n\u003cp\u003eThe NGS1 is the world-first filter that suppresses both man-made and night glow interferences to the green, orange and red ranges. This is the same filter that was previously sold as the IDAS LPS-D3.\u003c\/p\u003e\n\u003cspan\u003e \u003c\/span\u003e\n\u003cp\u003eNight Glow: OI (557.7nm, 630.0nm, 636.4nm), NaI (589.0nm, 589.6nm)\u003c\/p\u003e\n\u003cspan\u003e \u003c\/span\u003e\n\u003cp\u003eThe NGS1 the successor of the conventional IDAS light pollution cut filters, and thus can suppress the inteference from white LED lights. This filter is also effective against low- and high-pressure sodium lamp pollutions.\u003c\/p\u003e\n\u003cspan\u003e \u003c\/span\u003e\n\u003cp\u003eNight glow interferenced image (photo taken by Shigemi Numasawa):\u003c\/p\u003e\n\u003cspan\u003e \u003c\/span\u003e\n\u003cp\u003e\u003cpicture\u003e\u003csource type=\"image\/webp\" srcset=\"https:\/\/agenaastro.com\/media\/opti_image\/webp\/catalog\/product\/3\/0\/307-nightglow-s.webp\"\u003e\u003csource type=\"image\/jpg\" srcset=\"https:\/\/agenaastro.com\/media\/catalog\/product\/3\/0\/307-nightglow-s.jpg\"\u003e\u003cimg src=\"https:\/\/agenaastro.com\/media\/catalog\/product\/3\/0\/307-nightglow-s.jpg\" alt=\"\" width=\"325\" height=\"219\" decoding=\"async\" data-num=\"0\" id=\"img0\"\u003e\u003c\/source\u003e\u003c\/picture\u003e\u003c\/p\u003e\n\u003cspan\u003e \u003c\/span\u003e\n\u003cp\u003eImage ideally processed to reproduce the NGS1:effect\u003c\/p\u003e\n\u003cspan\u003e \u003c\/span\u003e\n\u003cp\u003e\u003cpicture\u003e\u003csource type=\"image\/webp\" srcset=\"https:\/\/agenaastro.com\/media\/opti_image\/webp\/catalog\/product\/3\/0\/307-nightglow-rs.webp\"\u003e\u003csource type=\"image\/jpg\" srcset=\"https:\/\/agenaastro.com\/media\/catalog\/product\/3\/0\/307-nightglow-rs.jpg\"\u003e\u003cimg src=\"https:\/\/agenaastro.com\/media\/catalog\/product\/3\/0\/307-nightglow-rs.jpg\" alt=\"\" width=\"325\" height=\"219\" decoding=\"async\" data-num=\"1\" id=\"img1\"\u003e\u003c\/source\u003e\u003c\/picture\u003e\u003c\/p\u003e\n\u003cspan\u003e \u003c\/span\u003e\n\u003cp\u003e The NGS1 is designed based on the same concept as of the other IDAS light pollution cut filters so that it maxmizes  the  transfer of the light emissions from various emission nebulae, C2 comae of comet heads and CO+ ionized tails of  comet  tails as well as coninuous spectrum emissions from space. Its transmittance range is intentionally shifted to the  longer wave length side. allowing margins for \"the shift tendency towards the shorter wave length side against oblique incidences\" typically associated with thin-film interference filters. The NGS1 can almost fully transfer the abovementioned nebular emission lines under the conditions , for example, where the incidence of the parallel flux is kept below 14 degrees, or a lens of the F value 2 or faster (or 1.4 or faster depending on lens) is used before this filter.\u003c\/p\u003e\n\u003cspan\u003e \u003c\/span\u003e\n\u003cp\u003eThe NGS1 filter utilizes the IGAD (ion-Gun AssistDeposition) coating technology which has been applied to our coventional light pollution cut filters. The IGAD technology densifies the multi-layers - the heart of interference filters - resulting in the physical properties that cannot be obtained from the conventional multi-layers.\u003c\/p\u003e\n\u003col\u003e\n\u003cli\u003eHighly durable thin layers of which hardness equals to quartz glasses. Tremendously improved adherence between the\u003cbr\u003esubstrate and the multi-layers set.\u003c\/li\u003e\n\u003cli\u003eAbsolutely almost no aging variation in optical spectral characteristics due to temperature and humidity change as\u003cbr\u003efar as used in the regular human living environments.\u003c\/li\u003e\n\u003c\/ol\u003e\n\u003cp\u003e*This product is an interference filter.  Its spectrum characteristics will be subject to the incidence of incoming light. Please carefully read the following instruction for proper use:\u003c\/p\u003e\n\u003cspan\u003e \u003c\/span\u003e\n\u003cp\u003e\u003cstrong\u003eWhen the NGS1 is placed before the lens:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cspan\u003e \u003c\/span\u003e\n\u003cp\u003eUse a lens having the light incidence angle of 14 degrees or lower (field angle of 34 degrees or lower).\u003c\/p\u003e\n\u003cspan\u003e \u003c\/span\u003e\n\u003cp\u003e\u003cpicture\u003e\u003csource type=\"image\/webp\" srcset=\"https:\/\/agenaastro.com\/media\/opti_image\/webp\/catalog\/product\/n\/g\/ngs-front.webp\"\u003e\u003csource type=\"image\/jpg\" srcset=\"https:\/\/agenaastro.com\/media\/catalog\/product\/n\/g\/ngs-front.jpg\"\u003e\u003cimg src=\"https:\/\/agenaastro.com\/media\/catalog\/product\/n\/g\/ngs-front.jpg\" alt=\"\" width=\"500\" height=\"271\" decoding=\"async\" data-num=\"2\" id=\"img2\"\u003e\u003c\/source\u003e\u003c\/picture\u003e\u003c\/p\u003e\n\u003cspan\u003e \u003c\/span\u003e\n\u003cp\u003e\u003cstrong\u003eSpecifications:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eM48 x 0.75\u003c\/li\u003e\n\u003cli\u003eFilter thickness: 2.0mm (Previous version NGS1-48mmS was 2.5mm thick)\u003c\/li\u003e\n\u003cli\u003eLightweight frame\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"prose\"\u003e\n\u003chr\u003e\n\u003ch2\u003eOther Information\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eCountry of Manufacture: Japan\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e","brand":"Astro-Hutech","offers":[{"title":"Default Title","offer_id":49163773083907,"sku":"U2607-MS-HU-NGS1-48","price":125.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1979\/5379\/files\/6b549502-1d9a-4646-873c-0d8354366d00.jpg?v=1783120821","url":"https:\/\/milehighastro.com\/products\/used-hutech-idas-ngs1-light-pollution-filter-2","provider":"Mile High Astronomy","version":"1.0","type":"link"}