{"product_id":"william-optics-ad-2x42-m48","title":"William Optics M48 Filter Adapters for Cat Eyes Binoculars","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eEnables use of standard 2-inch (M48 x 0.75) filters\u003c\/li\u003e\n\u003cli\u003eConnects to the M44.5 x 0.75 objective threads on Cat Eyes Binoculars\u003c\/li\u003e\n\u003cli\u003eAdds a minimal 6 mm of optical length to the light path\u003c\/li\u003e\n\u003cli\u003ePrecision-machined from black-anodized aluminum\u003c\/li\u003e\n\u003cli\u003eSold individually\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\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\u003eM48 Filter Adapters for Cat Eyes Binoculars\u003c\/h2\u003e\n      \u003cp\u003eThe M48 Filter Adapter for Cat Eyes Binoculars directly converts the binocular's native M44.5 x 0.75 objective thread to the standard M48 x 0.75 (2-inch) filter thread, adding only 6 mm of optical length to your optical train. This simple, robust adapter unlocks the ability to use a vast range of nebula, light pollution, and color filters to dramatically enhance your visual observing.\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\u003eAdd 2-inch (M48) Filter Capability to Your Cat Eyes Binoculars\u003c\/h3\u003e\n      \u003cp\u003eThis adapter solves the primary challenge of using filters with Cat Eyes Binoculars by providing a secure M48 threaded interface. By attaching nebula filters, you can significantly increase the contrast between faint deep-sky objects and the light-polluted sky, revealing detail that would otherwise be invisible. The adapter adds just 6 mm to the optical path, a minimal length designed to maintain focus capability.\u003c\/p\u003e\n      \u003cul\u003e\n        \u003cli\u003e\n\u003cstrong\u003eDirect Connection:\u003c\/strong\u003e The female M44.5 x 0.75 threads are designed for a perfect fit on the objective housing of Cat Eyes Binoculars.\u003c\/li\u003e\n        \u003cli\u003e\n\u003cstrong\u003eUniversal Filter Mount:\u003c\/strong\u003e The male M48 x 0.75 threads accept any standard 2-inch astronomy filter from any manufacturer.\u003c\/li\u003e\n        \u003cli\u003e\n\u003cstrong\u003eDurable Construction:\u003c\/strong\u003e Machined from a single piece of black-anodized aluminum to reduce internal reflections and withstand years of field use.\u003c\/li\u003e\n      \u003c\/ul\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n  \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eHow does using the M48 Filter Adapter help when viewing the Orion Nebula (M42) with my Cat Eyes Binoculars?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eThis adapter allows you to attach a UHC or other light pollution filter directly to your Cat Eyes Binoculars. For a target like the Orion Nebula (M42), this darkens the sky background and selectively passes the light emitted by the nebula, making its faint, extended structures stand out with much higher contrast.\u003c\/p\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eWill the 6mm optical length of the M48 adapter cause focusing issues on my Cat Eyes Binoculars?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eFor most visual applications, the \u003cstrong\u003e6 mm of added optical length\u003c\/strong\u003e is well within the focus travel range of the Cat Eyes Binoculars. This minimal extension is specifically designed to ensure you can still reach a sharp focus with your filters installed.\u003c\/p\u003e\n  \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eWhat kind of filters can I use with the M48 Filter Adapter for Cat Eyes Binoculars?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eYou can use any standard 2-inch mounted astronomy filter. The \u003cstrong\u003eM48 x 0.75 thread\u003c\/strong\u003e is the universal standard for this filter size, giving you access to a wide variety of options:\u003c\/p\u003e\n    \u003cul\u003e\n        \u003cli\u003eBroadband Light Pollution Filters (LPR)\u003c\/li\u003e\n        \u003cli\u003eNarrowband Filters (UHC, OIII, H-Beta)\u003c\/li\u003e\n        \u003cli\u003eColor Filters for planetary viewing\u003c\/li\u003e\n    \u003c\/ul\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eDoes this M48 adapter thread directly onto the objective lens of the Cat Eyes Binoculars?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eYes. The adapter's female \u003cstrong\u003eM44.5 x 0.75\u003c\/strong\u003e side is engineered to thread directly onto the objective cell of the Cat Eyes Binoculars, typically replacing a factory-installed protective ring or dew shield extension. The male M48 x 0.75 side then faces outward to accept your filter.\u003c\/p\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eAre these M48 Filter Adapters sold individually or as a pair?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eThese adapters are sold \u003cstrong\u003eindividually\u003c\/strong\u003e. To use filters on both optical tubes of your Cat Eyes Binoculars for a balanced view, you will need to purchase two adapters.\u003c\/p\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eIs the M48 Filter Adapter compatible with other brands of binoculars?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eIt is specifically designed for the \u003cstrong\u003eM44.5 x 0.75 threads\u003c\/strong\u003e found on Cat Eyes Binoculars. It is highly unlikely to be compatible with other binoculars unless they happen to use the exact same, non-standard objective thread size.\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      \u003ctr\u003e\n\u003ctd\u003eFilter Thread (Light-In)\u003c\/td\u003e\n\u003ctd\u003eM48 × 0.75 (Standard 2-inch)\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eBinocular Thread (Light-Out)\u003c\/td\u003e\n\u003ctd\u003eM44.5 × 0.75\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eOptical Path Length\u003c\/td\u003e\n\u003ctd\u003e6 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\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\"\u003eM48 Filter Adapter for Cat Eyes Binoculars\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\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eDavid Astro General Accessories Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"William Optics","offers":[{"title":"Default Title","offer_id":52853689909533,"sku":"WO-AD-2X42-M48","price":12.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/WilliamOptics-M48-Filter-Adapters-for-Cat-Eyes-Binoculars-1_25854592-5d79-47b3-85c4-ea9078530b36.jpg?v=1788457760","url":"https:\/\/davidastro.com\/products\/william-optics-ad-2x42-m48","provider":"David Astro","version":"1.0","type":"link"}