{"product_id":"optolong-nd30-neutral-density-filter","title":"Optolong ND3.0 Neutral Density Filter","description":"\u003ch2\u003eOptolong ND3.0 Neutral Density Filter\u003c\/h2\u003e\n\u003cp\u003eNeutral Density (ND) filters are designed to reduce transmission evenly across a portion of a specific spectrum. ND filters are typically defined by their Optical Density (OD) which describes the amount of energy blocked by the filter. A high optical density value indicates very low transmission, and low optical density indicates high transmission (Equations 1-2). ND filters can be stacked to achieve a customs optical density. To calculate the final system OD, simply add the OD of each filter together.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eTypes of Neutral Density Filters\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThere are two types of ND filters: reflective and absorptive.\u003c\/p\u003e\n\u003cp\u003eReflective ND filters consist of thin film optical coating, typically metallic, that have been applied to a galls substrate. The coating can be optimized for specific wavelength ranges such as UV-VIS or NIR. Thin film coating primarily reflects light back toward the source. Special care should be taken to ensure the reflected light does not interfere with the system setup.\u003c\/p\u003e\n\u003cp\u003eAbsorptive ND filters utilize a glass substrate to absorb light by a specific percentage.\u003c\/p\u003e\n\u003cp\u003eWARNING: The filters of Optolong are not designed for sun observation. DO NOT LOOK AT THE SUN WITH OPTOLONG FILTER. You would be BLIND if you fail to observe the warning.\u003c\/p\u003e\n\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\n\u003cp\u003e\u003cspan\u003eSubstrate: optical galss\u003c\/span\u003e\u003cbr\u003e\u003cspan\u003eThickness: 1.85mm\u003c\/span\u003e\u003cbr\u003e\u003cspan\u003eT=0.1%\u003c\/span\u003e\u003cbr\u003e\u003cspan\u003eSurface quality: 60\/40\u003c\/span\u003e\u003cbr\u003e\u003cspan\u003eTransmitted Wavefront RMS: λ\/4\u003c\/span\u003e\u003cbr\u003e\u003cspan\u003eParallelism: 30s\u003c\/span\u003e\u003c\/p\u003e\n\u003ch3\u003eIn The Box\u003c\/h3\u003e\n\u003cp\u003eFilter\u003c\/p\u003e\n\u003ch3\u003eManuals \u0026amp; Warranty\u003c\/h3\u003e\n\u003cp\u003eOptolong 3-Years Warranty\u003c\/p\u003e","brand":"Optolong","offers":[{"title":"1.25\"","offer_id":67843240853777,"sku":"dww1792663831179","price":34.9,"currency_code":"USD","in_stock":true},{"title":"2\"","offer_id":67843240886545,"sku":"glc1792663831180","price":53.75,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0971\/7242\/2929\/files\/optolong-nd30-neutral-density-filter_1.png?v=1792663837","url":"https:\/\/rollingdrawerclad.shop\/products\/optolong-nd30-neutral-density-filter","provider":"My Store","version":"1.0","type":"link"}