{"product_id":"astronomik-cls-light-pollution-filter-2-pre-owned","title":"Astronomik CLS Light Pollution Filter 2\" (Pre-owned)","description":"\u003cdiv class=\"card__header\"\u003e\n\u003ch2 class=\"card__title heading h3\"\u003eDescription\u003c\/h2\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"card__section\"\u003e\n\u003cdiv class=\"rte text--pull\"\u003e\n\u003cp\u003e\u003cstrong\u003eAstronomik CLS filters are suitable under light-polluted skies for DSLR Cameras which have not been modified for astronomical use.  \u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe Astronomik CLS is a budget filter for visual observation, black \u0026amp; white photography and CCD photographs of nebulae, galaxies and star clusters with astronomical instruments of any size.\u003c\/p\u003e\n\u003cp\u003eThe Astronomik CLS blocks the light of the spectral lines of mercury and sodium-vapor lamps and lets the largest part of the visible light and H-alpha emissions pass. All the important emission lines, as well as the spectral region that the very well dark adapted eye can see, can pass through the filter.\u003c\/p\u003e\n\u003cbr\u003e\n\u003ch4\u003eMain Uses\u003c\/h4\u003e\n\u003cp\u003eThe filters are optimized for use with aperture ratios from 1:3 to 1:15. Transmission losses and chromatic distortions, which are problems with other filters, only appear with Astronomik filters when extremely bright aperture ratios of 1:2 and more are used. The CLS filter is suitable for use with telescopes of all aperture sizes.\u003c\/p\u003e\n\u003cdiv class=\"basic ui-accordion\" id=\"list1b\"\u003e\u003ca href=\"https:\/\/www.astronomik.com\/en\/visual-filters.html\" rel=\"noopener\" aria-describedby=\"a11y-new-window-message\" target=\"_blank\"\u003e\u003c\/a\u003e\u003c\/div\u003e\n\u003ch4\u003eSuitability\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003eVisual observation (dark skies): Good, to reduce light pollution by mercury-vapour lamps (streetlight)\u003c\/li\u003e\n\u003cli\u003eVisual observation (urban skies): Good, an UHC-E or UHC filter is more suitable\u003c\/li\u003e\n\u003cli\u003eFilm photography: Very good, colour balance is near perfect\u003c\/li\u003e\n\u003cli\u003eCCD photography: Good, when used with an additional IR-block-filter\u003c\/li\u003e\n\u003cli\u003eDSLR photography (original): Good, colour balance shifted but contrast enhanced\u003c\/li\u003e\n\u003cli\u003eDSLR photography (astro modified): Very good, colour balance is near perfect\u003c\/li\u003e\n\u003cli\u003eDSLR photography (MC modified): Good, when used with an additional IR-block-filter\u003c\/li\u003e\n\u003cli\u003eWebcam \/ Video (Planets): Unsuitable\u003c\/li\u003e\n\u003cli\u003eWebcam \/ Video (Deep Sky): Very good, if light pollution is a big problem\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eTechnical Data\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003e92% transmission at 486nm (H-beta)\u003c\/li\u003e\n\u003cli\u003e92% transmission at 496nm (O\u003cspan\u003eIII\u003c\/span\u003e)\u003c\/li\u003e\n\u003cli\u003e92% transmission at 501nm (O\u003cspan\u003eIII\u003c\/span\u003e)\u003c\/li\u003e\n\u003cli\u003e97% transmission at 656nm (H alpha)\u003c\/li\u003e\n\u003cli\u003epass from 450 to 540nm and beyond 650nm\u003c\/li\u003e\n\u003cli\u003ePar focal with other Astronomik filters\u003c\/li\u003e\n\u003cli\u003eGlass thickness: 1mm\u003c\/li\u003e\n\u003cli\u003eCompletely resistant against high humidity, scratches and aging effects\u003c\/li\u003e\n\u003cli\u003eDiffraction limited, the filter will not reduce the optical performance of your telescope!\u003c\/li\u003e\n\u003cli\u003eAstronomik filters are delivered in a high-quality, long lasting, filter box\u003c\/li\u003e\n\u003cli\u003eSince 2008 we do ship filters with a completely new design. Any kind of halo or strange reflection is a matter of past\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e","brand":"Astronomik","offers":[{"title":"Default Title","offer_id":43153424449649,"sku":"USED041704","price":174.95,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0851\/2766\/files\/astronomik-filter-2-m48-astronomik-cls-light-pollution-filter-16148759183440.webp?v=1776452918","url":"https:\/\/khanscope.com\/fr\/products\/astronomik-cls-light-pollution-filter-2-pre-owned","provider":"Khan Scope Centre","version":"1.0","type":"link"}