Skip to content

Useful against some lamps, and honest about the rest

The best light pollution filters for 2026

A light pollution filter blocks the wavelengths that street lighting emits and passes the rest, and how well that works depends entirely on what the street lights are. Against the old high-pressure sodium lamps, whose output sits in a few narrow bands, these filters were remarkably effective, and their reputation was built in those years. Against modern white LED street lighting, which emits across the whole visible spectrum, there is no narrow band to remove, and a filter that removes enough to matter removes the object with it. That is the honest starting point, and the maker who publishes a transmission curve rather than a claim is the one worth reading. What remains genuinely useful divides in two. For visual work, a broadband filter still lifts emission nebulae out of a bright sky, and does almost nothing for galaxies and clusters, for the same reason a nebula filter does not. For photographic work, the calculation changes: a filter that costs some signal but suppresses a strong gradient can make a stack far easier to process, and dedicated designs for color cameras sit on this shelf. Every one of them introduces a color cast that has to be corrected afterwards, and how severe that is belongs in the comparison. Read the thread size against the eyepiece or the camera nosepiece, and read whether the filter is specified for fast focal ratios, where the angle of the light through the coating shifts the band. We compare blocked wavelengths and published curve, LED and sodium behavior, visual or photographic design, coating and glass, color cast, thread size, weight, focal ratio limits and the maker reference.

By

The parts here, column by column

  1. SVBONY 1.25 inch CLS light pollution filter

    SVBONY CLS 1.25 in (FUSF9155A)

    SVBONY's 1.25-inch CLS broadband filter: 90% transmission at the H-beta, OIII, H-alpha and SII nebula lines and 0.1% at the sodium and mercury lines of artificial lighting, with ion-assisted coatings.

    Blocked wavelengths and published curve
    Off-band 0.1% at sodium 589 nm and mercury 435 and 578 nm · pass-band 90% at H-beta 486, OIII 496 and 500, H-alpha 656, SII 672 nm
    LED and sodium behavior
    Sodium and mercury lines blocked, stated · LED behavior not stated
    Visual or photographic design
    Broadband, stated suitable for color CCD cameras and unmodified DSLRs
    Color cast
    Not published by the maker.
    Thread size
    1.25 in
    Focal ratio limits
    Not published · central wavelength stated stable with temperature
    Amazon reference
    B079BWD595
    EAN
    0609378745577
    • Pass-band and off-band transmissions published at named lines
    • Ion-assisted deposition coating, stated durable
    • Little effect on white LED light pollution

    Best for: Imaging or observing emission nebulae from a town, with a color camera or by eye

    ≈ $32
    Check price on Amazon
  2. K&F Concept Nano-X 67 mm natural night filter

    K&F CONCEPT Nano-X Natural Night 67 mm

    K&F Concept's Nano-X Natural Night filter: a 67 mm camera-lens filter that blocks sodium streetlight wavelengths of about 580 to 610 nm, in Japanese optical glass with a 28-layer coating on both faces.

    Blocked wavelengths and published curve
    About 580 to 610 nm blocked, stated · no curve published
    LED and sodium behavior
    Targets the yellow, beige and orange light of common artificial sources (sodium) · LED behavior not stated
    Visual or photographic design
    Photographic: a 67 mm camera-lens filter for night landscape and astrophotography
    Coating and glass
    Japanese optical glass · 28-layer nano coating on both faces · scratch, water, oil and dust resistant
    Thread size
    67 mm (2.64 in) camera-lens thread
    Weight
    68 g (2.4 oz)
    Focal ratio limits
    Not published by the maker.
    Maker reference
    FT011117 (Nano-X series)
    Amazon reference
    B07PG785HC
    EAN
    6936069223248
    • Blocked band published: about 580 to 610 nm
    • 28-layer coating on both faces
    • Camera-lens filter: does not fit a telescope eyepiece

    Best for: Wide-field tracked photography with a 67 mm camera lens under sodium-lit skies

    Check price on Amazon

Any figure written into the body of this page was true on the day it was written. The amount shown next to each instrument is requested from the retailer as the page loads, and it is that amount, not the text, that stands.