{"product_id":"shelyak-ba0036","title":"Shelyak C\/CS Adapter Ring (5mm Spacer)","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eProvides 5mm of critical spacing\u003c\/li\u003e\n\u003cli\u003eAdapts C-mount lenses for use on CS-mount cameras\u003c\/li\u003e\n\u003cli\u003eStandard C-mount (male) to CS-mount (female) threads\u003c\/li\u003e\n\u003cli\u003ePrecision-machined metal construction for secure connection\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\n\u003cli\u003eIn the Box\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\u003eC\/CS Adapter Ring (5mm Spacer)\u003c\/h2\u003e\n      \u003cp\u003eThis C\/CS adapter ring provides the essential 5mm of spacing required to achieve perfect focus when using standard C-mount lenses on cameras with a CS-mount. Many modern astronomical guide cameras and planetary imagers use the CS-mount standard, which has a shorter flange-to-sensor distance than the C-mount standard common on security and industrial lenses.\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\u003eBridge the 5mm Back Focus Gap for C-Mount Lenses\u003c\/h3\u003e\n      \u003cp\u003eC-mount lenses are designed to focus at a point farther away from the sensor than a native CS-mount camera can accommodate. Without correction, a C-mount lens will be unable to reach infinity focus on a CS-mount camera. This adapter ring acts as a simple, rigid 5mm extension that precisely bridges this mechanical gap, restoring the correct back focus.\u003c\/p\u003e\n      \u003cp\u003eInstallation is straightforward: simply thread the adapter onto your CS-mount camera body, and then thread your C-mount lens into the adapter. It's a fundamental accessory for anyone repurposing C-mount optics for astronomical imaging and is often paired with a T-mount to C-mount ring for connecting to a telescope's optical train.\u003c\/p\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\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 this C\/CS adapter ring used for?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eThis is a \u003cstrong\u003e5mm spacer\u003c\/strong\u003e designed to let you use a \u003cstrong\u003eC-mount lens\u003c\/strong\u003e on a \u003cstrong\u003eCS-mount camera\u003c\/strong\u003e. It adds the necessary distance between the lens and the camera sensor to allow the lens to achieve proper focus, especially at infinity.\u003c\/p\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eWhy do I need a 5mm spacer for a C-mount lens on my CS-mount camera?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eThe C-mount and CS-mount standards have different back focus requirements—the required distance from the lens mounting flange to the sensor plane. C-mount lenses require a longer distance. This 5mm ring provides that exact amount of extra spacing needed for a C-mount lens to work correctly on a CS-mount body.\u003c\/p\u003e\n  \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use this C\/CS adapter ring to put a CS-mount lens on a C-mount camera?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eNo, this adapter will not work for that purpose. A CS-mount lens needs to be closer to a C-mount sensor, but this adapter only adds distance. Attempting to use a CS-mount lens on a C-mount camera, even without an adapter, will typically result in an inability to reach focus.\u003c\/p\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eWill this 5mm C\/CS adapter ring work with my ZWO ASI120MM Mini guide camera?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eYes. The ZWO ASI120MM Mini, like many popular guide cameras, has a CS-mount. If you want to use a C-mount guide lens with it, you will need this 5mm C\/CS adapter ring to achieve focus. This applies to most cameras that ship with a CS-mount as their primary interface.\u003c\/p\u003e\n  \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eWhat happens if I don't use this C\/CS adapter ring with my C-mount security lens?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eWithout this 5mm adapter, your C-mount security or industrial lens will not be able to focus on a CS-mount camera. The image will be blurry because the lens cannot be moved far enough away from the sensor to form a sharp image. This ring is the essential component to make that combination work.\u003c\/p\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eHow does this C\/CS adapter ring work with a T-mount adapter?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eIt's common to use a T-to-C-mount adapter to connect a CS-mount camera to a telescope focuser or other T-threaded accessory. In this setup, the 5mm C\/CS ring would typically be threaded onto the camera first, followed by the T-to-C-mount adapter, ensuring all spacing requirements are met.\u003c\/p\u003e\n  \u003c\/div\u003e\n\u003c\/li\u003e\n\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\"\u003eC\/CS Adapter Ring\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\u003c\/ul\u003e","brand":"Shelyak","offers":[{"title":"Default Title","offer_id":52943027372317,"sku":"SHK-BA0036","price":41.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Shelyak-C-CS-adapter-ring-1_f0cb25ff-f190-43f0-a271-1d8c1ba476c5.jpg?v=1789615818","url":"https:\/\/davidastro.com\/en-us\/products\/shelyak-ba0036","provider":"David Astro","version":"1.0","type":"link"}