SVBONY SV139 · 1.25″ NEUTRAL DENSITY FILTERS
A more comfortable view of the Moon
Reduce bright lunar glare while keeping the Moon’s natural colour. Choose one fixed strength or the complete four-filter set.
The SVBONY SV139 Moon filters reduce the amount of light reaching your eye through the telescope. Each optical-glass filter screws into a compatible 1.25-inch eyepiece, helping make a bright lunar image more comfortable to examine.
The four versions share the same fitting. The difference is their neutral density and light transmission: a higher ND value gives a darker view. These are fixed-strength filters, so choose the version that suits your observing setup.
Choose your filter strength
| Version | SKU | Light transmitted* | Dimming level |
|---|---|---|---|
| ND0.6 | W9108A | 25% | Lightest of these four |
| ND0.9 | W9108B | 12.5% | More dimming |
| ND1.2 | W9108C | 6.25% | Stronger dimming |
| ND3.0 | W9108D | 0.1% | Very strong dimming |
*Nominal transmission values stated by SVBONY. ND numbers are optical-density ratings, not transmission percentages.
Which one should I choose?
Consider the brightness you actually see at the eyepiece. Moon phase, telescope aperture, magnification and personal comfort all affect how much dimming feels useful. ND0.6 is the least restrictive starting point in this range. Move to a darker option if the image remains uncomfortably bright.
ND3.0 transmits just 0.1% and is a much larger step than the other options. It can make the view too dim in some setups; it should not be treated as the automatic choice for every full-Moon session.
Simple threaded fitting
The aluminium cell uses a standard M28.5 × 0.6 thread. Screw it into the matching filter thread on a 1.25-inch eyepiece barrel. Check that your eyepiece accepts threaded filters; a plain 2-inch fitting requires an appropriate compatible adapter.
Single filter or full set?
Individual strength: one filter in the ND version selected above.
Full set: four filters—ND0.6, ND0.9, ND1.2 and ND3.0—so you can compare strengths and adapt the view to different sessions.
Solar safety: these Moon filters are not standalone solar filters. Never point a telescope at the Sun using a Moon filter as protection.
Explore more SVBONY telescope filters, or ask Dark Clear Skies for help choosing a strength for your telescope.
