{"product_id":"player-one-2-5mm-cs-lens","title":"Player One 2.5mm CS lens","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e2.5mm Focal Length\u003c\/li\u003e\n\u003cli\u003eCS-Mount Standard\u003c\/li\u003e\n\u003cli\u003eUltra-Wide Field of View\u003c\/li\u003e\n\u003cli\u003eIdeal for All-Sky Cameras\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\u003eDownloads\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\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\u003e2.5mm CS lens\u003c\/h2\u003e\n      \u003cp\u003eThis 2.5mm CS lens is designed for a single purpose: capturing an extremely wide, horizon-to-horizon field of view. The short 2.5mm focal length is ideal for all-sky cameras, meteor detection systems, and atmospheric monitoring stations where situational awareness is more critical than high-resolution detail.\u003c\/p\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"DAV-bg-light\"\u003e\n    \u003cdiv class=\"DAV-section\"\u003e\n      \u003ch3\u003eA 2.5mm Focal Length for All-Sky Imaging\u003c\/h3\u003e\n      \u003cp\u003eThe defining characteristic of this lens is its 2.5mm focal length, which produces a \"fisheye\" or near-fisheye perspective when paired with the small sensors typical of CS-mount cameras. This allows you to capture the entire visible sky in a single frame, making it a powerful tool for automated monitoring projects.\u003c\/p\u003e\n      \u003cul\u003e\n        \u003cli\u003e\n\u003cstrong\u003eMeteor and Fireball Networks:\u003c\/strong\u003e Capture the full path of bright meteors against a fixed star-field background for triangulation and analysis.\u003c\/li\u003e\n        \u003cli\u003e\n\u003cstrong\u003eObservatory Cloud Monitoring:\u003c\/strong\u003e Get an instant, 24\/7 view of sky conditions to know when it's clear enough to open the dome.\u003c\/li\u003e\n        \u003cli\u003e\n\u003cstrong\u003eAurora and Airglow Imaging:\u003c\/strong\u003e The ultra-wide perspective is perfect for framing large-scale, dynamic atmospheric phenomena like the aurora borealis.\u003c\/li\u003e\n        \u003cli\u003e\n\u003cstrong\u003eTrade-Offs:\u003c\/strong\u003e Be aware that a 2.5mm focal length prioritizes field of view over image scale. There will be significant geometric distortion toward the edges, and individual objects will be very small. This lens is for capturing context, not close-up details.\u003c\/li\u003e\n      \u003c\/ul\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\n\n\n\u003c\/div\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n  \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the primary application for the 2.5mm CS lens?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eThe primary application is \u003cstrong\u003eall-sky imaging\u003c\/strong\u003e. Its 2.5mm focal length is designed to capture the widest possible field of view, making it ideal for meteor cameras, observatory weather stations, and monitoring large-scale atmospheric events like the aurora.\u003c\/p\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eWhat kind of camera mount does the 2.5mm CS lens use?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eThis lens uses the \u003cstrong\u003eCS-mount standard\u003c\/strong\u003e. This is a common threaded mount found on many security, industrial, and specialized small-format astronomy cameras, particularly those used for guiding or planetary imaging that have been repurposed for all-sky work.\u003c\/p\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eWill I see distortion with the 2.5mm CS lens?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eYes, significant geometric distortion is an inherent characteristic of such a short focal length lens. Stars and objects near the edge of the field will appear stretched. This is a normal trade-off for achieving an ultra-wide, \"fisheye\" perspective.\u003c\/p\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eIs the 2.5mm CS lens suitable for imaging planets or galaxies?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eNo, this lens is not designed for high-magnification imaging. Its purpose is to provide the widest possible field of view, which means planets and galaxies would appear as unresolved points of light. For detailed imaging of celestial objects, you need a telescope with a much longer focal length.\u003c\/p\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the 2.5mm CS lens to build a meteor camera for the Perseids?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eAbsolutely. This is an ideal use case. The 2.5mm focal length will capture a massive swath of the sky, maximizing your chances of recording meteor trails during major showers like the Perseids or Geminids without needing to aim the camera precisely.\u003c\/p\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eWould this 2.5mm CS lens work for a permanent cloud monitoring station?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eYes, it is perfectly suited for this role. Mounted in a weatherproof enclosure and connected to a small astronomy camera, the 2.5mm CS lens can provide a continuous, horizon-to-horizon view of your local sky conditions, day or night.\u003c\/p\u003e\n  \u003c\/div\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n  \u003ctable class=\"DAV-specifications\"\u003e\n    \u003ctbody\u003e\n      \n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n  \u003cul class=\"DAV-grid\"\u003e\n    \n  \u003c\/ul\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\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":52913427841309,"sku":"POA-25LENS","price":22.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/PlayerOne-2-5mm-CS-lens-1_d1dc43d2-3bb0-49a5-aaaf-81455b4f11b2.jpg?v=1789090965","url":"https:\/\/davidastro.com\/fr-us\/products\/player-one-2-5mm-cs-lens","provider":"David Astro","version":"1.0","type":"link"}