{"product_id":"celestron-filtro-ossigeno-iii-da-50-8mm","title":"Celestron 2-inch Oxygen III Filter","description":"\u003cdiv class=\"product-description\" style=\"font-family:Arial,sans-serif;font-size:16px;line-height:1.7;color:#333;\"\u003e\n\n\u003ch1 style=\"font-size:24px;font-weight:bold;\"\u003eCelestron 2\" Oxygen III Filter\u003c\/h1\u003e\n\n\u003cp style=\"font-size:18px;margin-top:10px;\"\u003eCelestron narrowband OIII filters isolate only the two doubly ionized oxygen lines (at 496 and 501nm wavelengths) emitted by planetary and emission nebulae, blocking all other wavelengths of the light spectrum. Using this filter often makes the difference between seeing and not seeing certain nebulae. The effect is particularly impressive with some well-known nebulae, such as the Veil (in Cygnus) and the Helix (in Aquarius). Without a filter, using small instruments, you often see nothing. With the filter, the nebula will be immediately apparent! Each filter features a high-hardness optical coating, applied using high-vacuum thin-film deposition techniques. The coating uses the principle of optical interference and is designed to block the entire visual spectrum from 400 to 700 nm. This eliminates the unnatural colored halos around bright stars that are typical of OIII filters built with less sophisticated high-vacuum deposition technologies. The filter diameter is 2 inches (50.8 mm). Celestron filters are designed to be screwed into eyepieces of the corresponding diameter. In fact, all modern eyepieces are equipped with filter threads. Celestron filters are also threaded on the opposite side with a female thread that allows you to screw multiple filters together if necessary. \u003c\/p\u003e\n\n\u003ch2 style=\"font-size:20px;margin-top:30px;\"\u003eMain features\u003c\/h2\u003e\n\n\u003cp\u003eCelestron quality for a reliable and fulfilling observation experience.\u003c\/p\u003e\n\n\u003cul style=\"padding-left:20px;\"\u003e\u003cli\u003eFilter diameter: 2\"\u003c\/li\u003e\u003c\/ul\u003e\n\n\u003ch2 style=\"font-size:20px;margin-top:30px;\"\u003eMain technical specifications\u003c\/h2\u003e\n\n\u003ctable style=\"width:100%;border-collapse:collapse;margin-top:10px;\"\u003e\u003ctbody\u003e\n\n\u003ctr\u003e\n\n\u003ctd style=\"padding:8px;border:1px solid #ccc;\"\u003eBrand\u003c\/td\u003e\n\n\u003ctd style=\"padding:8px;border:1px solid #ccc;\"\u003eCelestron\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\u003ctr\u003e\n\n\u003ctd style=\"padding:8px;border:1px solid #ccc;\"\u003eModel\u003c\/td\u003e\n\n\u003ctd style=\"padding:8px;border:1px solid #ccc;\"\u003eCelestron 2\" Oxygen III Filter\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\u003ctr\u003e\n\n\u003ctd style=\"padding:8px;border:1px solid #ccc;\"\u003eType\u003c\/td\u003e\n\n\u003ctd style=\"padding:8px;border:1px solid #ccc;\"\u003eNebula Filters\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\u003ctr\u003e\n\n\u003ctd style=\"padding:8px;border:1px solid #ccc;\"\u003eFilter diameter\u003c\/td\u003e\n\n\u003ctd style=\"padding:8px;border:1px solid #ccc;\"\u003e2\"\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\n\u003c\/tbody\u003e\u003c\/table\u003e\n\n\u003cdiv style=\"background-color:#f0f8ff;padding:15px;margin-top:30px;border-left:4px solid #007acc;\"\u003e\n\n\u003cstrong\u003eFree shipping\u003c\/strong\u003e\u003cbr\u003eTake advantage of free shipping throughout Italy on orders over €199.99!\u003c\/div\u003e\n\n\n\u003c\/div\u003e","brand":"Celestron","offers":[{"title":"Default Title","offer_id":51120709435608,"sku":"CE93624","price":211.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0766\/0722\/6072\/files\/39716208279768-pulita.jpg?v=1791320629","url":"https:\/\/www.giordanoastronomia.it\/en\/products\/celestron-filtro-ossigeno-iii-da-50-8mm","provider":"Giordano Astronomia","version":"1.0","type":"link"}