Wanderer Astro Filter Shim for 50mm Filters
- Designed for SFW50 & SFW50S Filter Wheels
- Adapts 50mm Unmounted Filters Thinner than 2.5mm
- Ensures Accurate and Stable Filter Seating
- Prevents Filter Tilt and Optical Artifacts
The 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.
Wanderer 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.
This 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.
You need the SFW50/SFW50S Filter Shim if you are using 50mm unmounted filters that are thinner than the wheel's 2.5mm slot depth. The shim fills the gap, preventing the filter from tilting or moving, which is critical for maintaining sharp, consistent focus and preventing optical artifacts.
You 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.
Without a shim, a thin filter will be loose within the 2.5mm slot. This can cause several problems during an imaging session:
This shim is specifically designed for the 2.5mm slot depth 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.
No, 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.
Installation 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.