{"product_id":"optolong-l-quad-enhance-filter-2","title":"Optolong 2\" L-Quad Enhance Broadband Filter - LQUAD2","description":"\u003cmeta charset=\"UTF-8\"\u003e\n\u003cp\u003e\u003cspan\u003eThe Optolong L-Quad Enhance Broadband Filter is designed for light pollution suppression with color cameras.  The L-QEF is a quad bandpass filter lowers the light generated by mercury and sodium lamps as well as natural skylight.  When used with a color CMOS camera, contrast is enhanced and objects are more distinct.  The filter provides better color balance while improving resistance to light pollution.  This 2\" L-Quad filter can be used for wide field astrophotography and deep-sky objects like nebulae, galaxies, star clusters and more.  It maximizes the color balance of nebulae, galaxies and other broadband spectral targets.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch4\u003e\u003cspan\u003eMajor Emission Lines of Nebulae:\u003c\/span\u003e\u003c\/h4\u003e\n\u003cp\u003e\u003cspan\u003eH-a - 656.3nm\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eH-b -486.1nm\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eOIII - 495.9nm\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eOIII - 500.7nm\u003c\/span\u003e\u003c\/p\u003e\n\u003ch4\u003e\u003cspan\u003eMajor Emission Lines of Artificial Light Pollution\u003c\/span\u003e\u003c\/h4\u003e\n\u003cp\u003e\u003cspan\u003eHg - 435.8nm, 546.1nm, 577nm, 578.1nm\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eNa - 598nm, 589.6nm, 615.4nm, 616.1nm\u003c\/span\u003e\u003c\/p\u003e\n\u003ch3 style=\"text-align: center;\"\u003e\u003cspan\u003eFeatures of the L-Quad Enhance 2\" Filter\u003c\/span\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eCuts out light pollution from mercury and sodium lamps and produces a nice broadband image with minimal color cast;\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cspan style=\"font-size: 0.875rem;\"\u003eSignal-to-noise ratio (SNR);\u003c\/span\u003e\u003cbr\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cspan style=\"font-size: 0.875rem;\"\u003eNear IR cut-off to 1000nm, reducing the effects of IR noise;\u003c\/span\u003e\u003cbr\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cspan style=\"font-size: 0.875rem;\"\u003eL-QEF has more than 90% transmittance of the nebula emission lines at H-Beta\/OIII\/H-Alpha\/SII, with cut-off depth from OD2 to OD4, thus providing a significant increase in resistance to light pollution. L-QEF is good for night sky from Bortel 1 to Bortel 7 levels; (Bortel 8, Bortel 9 environments are not  recommended);\u003c\/span\u003e\u003cbr\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cspan style=\"font-size: 0.875rem;\"\u003eSuitable for wide range of deep sky targets: it covers most nebulae, galaxies, star clusters, reflected and emitted line signals astronomical objects with higher contrast and rich details while maintaining excellent color balance. \u003c\/span\u003e\u003cbr\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3 style=\"text-align: center;\"\u003e \u003cstrong\u003eTechnical Data\u003c\/strong\u003e\n\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cspan\u003eSubstrate:  Optical glass\u003c\/span\u003e\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan\u003eThickness:  1.85 mm\u003c\/span\u003e\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan\u003eSurface Quality: 60\/40 (Refer to MIL-O-13830)\u003c\/span\u003e\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003eFine-optically polished to ensure accurate 1\/4 wavefront and \u0026lt; 30 seconds parallelism over the both surfaces\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan\u003eBlocking Range:  300 nm - 1000 nm\u003c\/span\u003e\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan\u003eBlocking Depth:  OD2 - OD4\u003c\/span\u003e\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan\u003eParallelism: 30s\u003c\/span\u003e\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003eMulti-layers of anti-reflection coating\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003eFWHM:  Quad bandpass filter\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Optolong","offers":[{"title":"Default Title","offer_id":40272219373681,"sku":"OPTO-LQUAD2","price":186.95,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0851\/2766\/files\/L-Quad_2inch_Filter.jpg?v=1776459036","url":"https:\/\/khanscope.com\/en-fr\/products\/optolong-l-quad-enhance-filter-2","provider":"Khan Scope Centre","version":"1.0","type":"link"}