Svbony Filter Drawer
Holds a 2 inch filter in a slide-out drawer so filters can be changed without taking the imaging trainThe chain of parts between the telescope and the sensor: flattener, spacers, filter drawer, camera. Every one of them takes up length, which is why the order and the spacing matter. apart. Focus and backfocusThe exact distance a flattener or reducer needs between itself and the sensor. Get it wrong and the stars at the edges of the frame stretch into little dashes, and no amount of processing will fix it. spacing stay untouched, which removes the main reason to avoid swapping filters part-way through a session.
A small part that removes a real obstacle
Changing a filter in a threaded imaging train means unscrewing the camera, swapping the filter and reassembling. In the dark, on a mounted telescope, that risks disturbing focus, rotating the framing and dropping something expensive. The usual result is that people stop changing filters mid-session.
A filter drawer holds the filter in a tray that slides out sideways. The train stays assembled, focus is undisturbed, the camera never rotates, and a five minute operation becomes a few seconds.
Why it matters here
It is the part that makes owning more than one filter practical. Swapping between the L-eXtreme for an emission nebulaA cloud of gas that glows with its own light, in a few exact colours, because nearby stars are energising it. This is the kind that narrowband filters are built for. and the L-Quad Enhance for a galaxy is a decision about what to point at, not a decision about whether it is worth dismantling the imaging train.
The SV220 adds a second narrowbandA filter that only lets through the few exact colours that glowing gas clouds give off, and blocks nearly everything else. Streetlight is mostly blocked, the nebula is not. option at 3nm, and the choice between it and the 7nm L-eXtreme is less about the target than about the night: how much moon is up, and how many hours I am likely to get. Without a drawer that decision gets made once, at the start, and lived with. With one I can open on the 3nm, fall back to the 7nm if conditions do not justify the extra signal loss, and stack the two sets separately.
Getting the spacing right
The drawer occupies space in the optical path and that space has to be accounted for. Every imaging train has a required distance between flattenerA small lens that corrects the naturally curved focus of a telescope, so the stars in the corners are as round as the ones in the middle. and sensor, and getting it wrong gives elongated stars towards the frame edges that no processing will rescue. So it is worth installing once, deliberately, with the other spacers adjusted to compensate, rather than adding it the night before a session.
Beyond that, check the drawer is light-tight when closed and that the tray seats in the same position every time, and make sure your filters are in carriers of the right depth for it.
Getting one to the UAE
Mine came from Svbony's own store on AliExpress and reached Dubai without issue. Buying from a manufacturer's official storefront rather than a third-party seller is worth the small effort of checking, particularly for a mechanical part where the exact optical thickness matters and a near-identical looking clone would quietly break your spacing.
Where to buy
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