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Baader Neodymium Moon and Skyglow Filter

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Narrow-band interference filters have been around for many years now. Nebula filters, “deep sky” filters, “Ultra-high contrast” filters, etc. All designed to enhance the viewing of emission nebulae by blocking specific wavelengths of artificial light sources, but letting the wavelengths of the viewed objects to pass through.

Personally, I’ve never cared much for them, as they all decrease overall brightness – some quite substantially – of the object in view, despite the fact that they DO increase contrast. Don’t get me wrong. I use an h-beta filter to view things like the Helix nebula and such. From my location, these objects would be invisible without one, but whenever possible I try to observe without a filter.

The The Baader Neodymium Moon and Skyglow filter is different. Unlike other filters that have a few transmission peaks for one or two specific wavelengths, this filter has a very complex transmission profile that allows much more light to pass through from a wider variety of objects, including stars, planets, and galaxies.

The filter looks pale purple, when looking through it at an object outdoors, doesn’t seem to do much. In a telescope, however, it works quite differently.

I would call it a “low-contrast filter” in that it doesn’t have the steep, sky-darkening effect of a typical UHC LPR, but what it cuts back on is definitely noticeable. What it doesn’t really do is diminish the brightness of the objects you are viewing, and to me, that is a BIG plus.

Nebulae appear more defined but not darker. Even galaxies and star clusters appear enhanced, albeit slightly. The sky surrounding an object ALWAYS seems darker with this filter, even though the object doesn’t.

Like it’s name suggests, this filter also helps the view of deep-sky objects in moonlight, something that other filters don’t do. The effect is slight, but there.

I tend not to screw my filters onto an eyepiece barrel, but rather hold them by hand and place them over the eyepiece itself. This way, I can simply hold it “in or out” of my view and immediately compare the view of filter versus no filter. The The Baader Neodymium Moon and Skyglow filter almost always gives me a more pleasing, contrast-enhanced view, with minimal dimming of the objects I’m looking at.

For a price of between $50 and $80 (depending on the size), it’s money well-spent.


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