{"product_id":"player-one-2-1mm-cs-lens","title":"Player One 2.1mm CS lens","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e2.1mm Focal Length\u003c\/li\u003e\n\u003cli\u003eCS-Mount Interface\u003c\/li\u003e\n\u003cli\u003e190° Field of View on 1\/2\" Sensors\u003c\/li\u003e\n\u003cli\u003e150° Field of View on 1\/3\" Sensors\u003c\/li\u003e\n\u003cli\u003eAll-Sky and Wide-Field Monitoring\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003e2.1mm CS lens\u003c\/h2\u003e\n\u003cp\u003eThis 2.1mm CS-mount lens is engineered for extreme wide-angle applications, delivering a 150° field of view when attached to a camera with a 1\/3\" sensor. When paired with a larger 1\/2\" sensor, the imaging circle expands to a full 190°, capturing a hemispheric vista ideal for all-sky cameras, meteor detection, and security monitoring.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eDual-Sensor Field of View: 150° on 1\/3\" and 190° on 1\/2\" Sensors\u003c\/h3\u003e\n\u003cp\u003eThe lens's utility is defined by the sensor it illuminates. On a smaller 1\/3\" sensor, common in guide cameras and planetary imagers, it produces a 150° diagonal field, offering a vast sky view suitable for wide-field framing or situational awareness. Attaching the lens to a camera with a 1\/2\" sensor utilizes the full image circle, creating a 190° fisheye perspective that can see from horizon to horizon in a single frame.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat kind of camera is the 2.1mm CS lens compatible with?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThis lens is designed for cameras that use the \u003cstrong\u003eCS-mount standard\u003c\/strong\u003e. This includes many dedicated all-sky cameras, security and surveillance cameras, and some specific astronomical guide cameras. It is not compatible with C-mount cameras without an adapter, nor will it work with DSLR or mirrorless cameras.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhy does the 2.1mm CS lens have two different fields of view listed?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe field of view depends entirely on the size of the camera sensor you pair it with. The lens projects a circular image; a smaller sensor captures a smaller portion of that circle, while a larger sensor captures more of it.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eOn a 1\/3\" sensor:\u003c\/strong\u003e The field of view is 150°.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOn a 1\/2\" sensor:\u003c\/strong\u003e The field of view increases to 190°.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the 2.1mm CS lens to build a meteor camera?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, this is an ideal application. For maximum sky coverage to capture meteor showers like the Perseids or Geminids, you should pair the 2.1mm lens with a 1\/2\" sensor camera. This combination achieves the 190° field of view, ensuring you can monitor the largest possible patch of sky all night.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the 2.1mm CS lens suitable for use as a wide-field guider?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWhile technically possible, it is not recommended for precise guiding. The extremely short 2.1mm focal length results in a very low image scale (many arcseconds per pixel), making it difficult for guiding software to detect the small star movements needed for accurate corrections on a long focal length telescope. It is designed for imaging the entire sky, not for high-magnification guiding.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDoes this 2.1mm CS lens have adjustable focus or aperture?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eLenses of this type are typically fixed-aperture and are focused by adjusting the lens's distance to the sensor by threading it in or out of the camera's CS-mount. Once focus is achieved for infinity, it is often locked in place for dedicated applications like all-sky monitoring.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill the 2.1mm CS lens show the entire Milky Way?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, when used with a 1\/2\" sensor to achieve the 190° field of view, this lens can easily capture the entire visible arch of the Milky Way in a single shot, from one horizon to the other. This makes it excellent for dramatic, wide-field astrophotography and time-lapses.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Length\u003c\/td\u003e\n\u003ctd\u003e2.1mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMount\u003c\/td\u003e\n\u003ctd\u003eCS-Mount\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eField of View (on 1\/3\" sensor)\u003c\/td\u003e\n\u003ctd\u003e150°\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eField of View (on 1\/2\" sensor)\u003c\/td\u003e\n\u003ctd\u003e190°\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003e2.1mm CS Lens\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003ca title=\"Player One 2-Year Warranty\" href=\"https:\/\/davidastro.com\/pages\/player-one-warranty-policy\" target=\"_blank\"\u003ePlayer One 2-Year Warranty\u003c\/a\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Player One","offers":[{"title":"Default Title","offer_id":52913428005149,"sku":"POA-21LENS","price":22.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/PlayerOne-2-1mm-CS-lens-1_cd9c6577-f99f-4e5a-a637-41d455761f27.jpg?v=1789090972","url":"https:\/\/davidastro.com\/en-us\/products\/player-one-2-1mm-cs-lens","provider":"David Astro","version":"1.0","type":"link"}