{"product_id":"wanderer-astro-sfw50-sfw50s-filter-shrim-for-50mm-filters-thinner-than-2-5mm","title":"Wanderer Astro Filter Shim for 50mm Filters","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eDesigned for SFW50 \u0026amp; SFW50S Filter Wheels\u003c\/li\u003e\n\u003cli\u003eAdapts 50mm Unmounted Filters Thinner than 2.5mm\u003c\/li\u003e\n\u003cli\u003eEnsures Accurate and Stable Filter Seating\u003c\/li\u003e\n\u003cli\u003ePrevents Filter Tilt and Optical Artifacts\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\u003eSFW50\/SFW50S Filter Shim for 50mm Filters thinner than 2.5mm\u003c\/h2\u003e\n\u003cp\u003eThe SFW50\/SFW50S Filter Shim is the essential adapter for using unmounted 50mm filters thinner than 2.5mm in compatible Wanderer Astro filter wheels. This precision ring solves the specific 2.5mm slot depth of the SFW50 and SFW50S, ensuring thin filters are seated securely without tilt for consistent imaging results.\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\u003eSecure Fit for Filters Under 2.5mm in SFW50\/SFW50S Wheels\u003c\/h3\u003e\n\u003cp\u003eWanderer Astro's SFW50 and SFW50S filter wheels are machined with a 2.5mm slot depth to accommodate a common standard for 50mm unmounted filters. However, if your filters are thinner than this, they can sit loosely in the carousel, leading to tilt. A tilted filter can introduce image shift, distorted star shapes, and internal reflections, compromising your data.\u003c\/p\u003e\n\u003cp\u003eThis shim ring fills the excess space, increasing the effective thickness of your filter for a snug, stable fit. By ensuring the filter remains perfectly perpendicular to the optical axis, the shim guarantees consistent focus and optical alignment every time the wheel rotates to a new position.\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\"\u003eWhy do I need this filter shim for my SFW50\/SFW50S filter wheel?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYou need the SFW50\/SFW50S Filter Shim if you are using 50mm unmounted filters that are thinner than the wheel's \u003cstrong\u003e2.5mm slot depth\u003c\/strong\u003e. The shim fills the gap, preventing the filter from tilting or moving, which is critical for maintaining sharp, consistent focus and preventing optical artifacts.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow do I know if my 50mm filters are thinner than 2.5mm?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYou will need to check the technical specifications provided by your filter's manufacturer. Most manufacturers list the thickness of their unmounted filters on the product page or packaging. If the specified thickness is less than 2.5mm, this shim is required for proper installation in an SFW50 or SFW50S wheel.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat happens if I use a thin 50mm filter in the SFW50 without a shim?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWithout a shim, a thin filter will be loose within the 2.5mm slot. This can cause several problems during an imaging session:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eFilter Tilt:\u003c\/strong\u003e The filter can sit at an angle, causing distorted star shapes, especially towards the edge of the field.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eImage Shift:\u003c\/strong\u003e As the wheel rotates, the filter can move slightly, causing a shift in the image frame between different filters.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInconsistent Focus:\u003c\/strong\u003e A tilted filter changes the effective light path length, which can ruin automated focus routines when switching between filters of different thicknesses.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs this SFW50\/SFW50S shim compatible with other brands of filter wheels?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThis shim is specifically designed for the \u003cstrong\u003e2.5mm slot depth\u003c\/strong\u003e and carousel design of the Wanderer Astro SFW50 and SFW50S filter wheels. While it may physically fit other 50mm filter wheels, compatibility and proper function are not guaranteed.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDoes the SFW50\/SFW50S shim affect the optical path?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, the shim is a mechanical spacer that sits around the edge of the filter. It does not protrude into the filter's clear aperture and therefore does not block any light or otherwise affect the optical performance.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow is the SFW50\/SFW50S filter shim installed?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eInstallation is straightforward. You simply place the shim into the filter slot in the carousel first, and then place your thinner-than-2.5mm filter on top of it. The combination of the shim and the filter will then correctly fill the 2.5mm slot, allowing you to secure it as you would a standard filter.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/wanderer-astro-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eWanderer Astro 2-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Wanderer Astro","offers":[{"title":"Default Title","offer_id":52940505186589,"sku":"WA-WSFW50-FS","price":25.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/WandererAstro-SFW50-SFW50S-Filter-Shim-for-50mm-Filters-thinner-than-2-5mm-1_9f06b49c-887a-4588-8c9e-1ac11b559101.jpg?v=1789571399","url":"https:\/\/davidastro.com\/products\/wanderer-astro-sfw50-sfw50s-filter-shrim-for-50mm-filters-thinner-than-2-5mm","provider":"David Astro","version":"1.0","type":"link"}