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IDAS NGS1 (LPS-D3) Night Glow Suppression Light Pollution Filter
IDAS NGS1 (LPS-D3) Night Glow Suppression Light Pollution Filter
IDAS NGS1 (LPS-D3) Night Glow Suppression Light Pollution Filter
IDAS NGS1 (LPS-D3) Night Glow Suppression Light Pollution Filter

IDAS NGS1 (LPS-D3) Night Glow Suppression Light Pollution Filter

by IDAS
SKU IDA-NGS1-48ST2
CA$245.00 - CA$347.00
CA$245.00
CA$245.00 - CA$347.00
CA$245.00
Price Match Policy!
  • Suppresses natural night glow emissions, including Oxygen (OI) at 557.7nm, 630.0nm, and 636.4nm
  • Blocks common man-made light pollution from LED, high-pressure, and low-pressure sodium lamps
  • Maintains high transmission for key deep-sky targets like emission nebulae and comets
  • Passband deliberately shifted toward longer wavelengths so nebular lines stay inside it at incidence angles up to about 14°
  • Features durable IGAD (Ion-Gun Assist Deposition) coatings for long-term spectral stability
  • Available in 7 formats, including 2" threaded and drop-in options for Canon, ZWO, and RASA 8 systems
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  • Description
  • FAQ
  • Specifications
  • In the Box
  • Downloads
  • Warranty

  • IDAS NGS1 (LPS-D3) Night Glow Suppression Light Pollution Filter

    The NGS1 (LPS-D3) is the world's first filter designed to suppress both man-made light pollution and natural atmospheric night glow. It specifically targets emissions from atmospheric Oxygen (OI) at 557.7nm and Sodium (NaI) at 589.0nm and 589.6nm. It also keeps suppression of high- and low-pressure sodium lamps and modern white LED lighting, maximizing signal from emission nebulae and comets even under compromised skies.

    Targeting 557.7nm OI: Suppressing Natural Night Glow & Man-Made LEDs

    Unlike traditional light pollution filters that only address artificial lighting, the NGS1 tackles a more persistent problem: natural airglow. This faint, ever-present light is produced by the Earth's own atmosphere, primarily from excited Oxygen (OI at 557.7nm, 630.0nm, 636.4nm) and Sodium (NaI at 589.0nm, 589.6nm). The NGS1 bandpass also blocks these specific wavelengths, on top of the man-made light pollution that conventional filters address.

    While pioneering this new level of suppression, the NGS1 retains the capabilities of IDAS's conventional LPS filters. It effectively blocks common light pollution sources and passes the main emission lines from deep-sky objects. It passes the light of emission nebulae, the C2 comae of comet heads, and the CO+ ionized tails of comets.

    Optimized for Fast Optics: Full Transmission with Incidence Angles Below 14°

    Interference filters are notoriously sensitive to the angle of incoming light, which can cause the filter's bandpass to shift toward shorter wavelengths and reduce transmission of your target's signal. This is a significant problem in fast, wide-field systems like astrographs and camera lenses. The IDAS NGS1 is specifically designed to counteract this effect.

    The filter's transmission range is intentionally shifted toward longer wavelengths, creating a margin that maintains performance even with highly oblique light rays. The NGS1 passes almost all of these nebular emission lines when the incidence of the light is kept below 14 degrees. Placed in front of a lens, use a lens whose light incidence angle is 14 degrees or lower (field angle of 34 degrees or lower). Placed between the lens and an APS-C camera, a lens with a back focal distance of 40mm or more at f/2 keeps the averaged incidence angle within about 14 degrees; lenses with a small rear element can exceed it at the edges of the frame.

    IGAD Coating Technology: Quartz-Hard Durability and Spectral Stability

    At the core of the NGS1 filter is IDAS's proprietary IGAD (Ion-Gun Assist Deposition) coating technology. This process creates multi-layer coatings that are far more dense and robust than those from conventional methods.

    • Hardness and Adherence: The IGAD layers have a hardness equal to quartz glass and a much stronger bond between the substrate and the multi-layer stack.
    • Environmental Stability: The spectral characteristics show almost no aging from temperature and humidity changes in normal living environments.

    7 Formats for Every System: From 2" Threaded to ZWO and Canon Drop-In

    The NGS1 comes in seven formats. Drop-in adapters and filter drawers are sold separately.

    • 2" (M48) and M52 Mounted: Threaded M48x0.75 (2") and M52x0.75 cells with a 2.0mm substrate.
    • DS Drop-in: For the IDAS AD42-DS drop-in mount adapter system.
    • Di2 Drop-in: Exclusively for the IDAS AD19.4 drop-in adapter used with Celestron RASA 8 astrographs.
    • DRT Drop-in: Designed for the Canon EF-EOS R drop-in mount adapter, as well as compatible adapters from Meike and Kolari.
    • DZ Drop-in: A frame for ZWO's FD-M54-II and FD-M42-II filter drawers. It features a larger 47mm clear aperture to reduce vignetting on full-frame sensors.
    • ZF: Drops into the T-ring of ZWO M42 male-mount cameras with a 6.5mm flange back, and also fits the IDAS AD19.4 drop-in mount.

  • What makes the IDAS NGS1 filter different from other light pollution filters?

    The IDAS NGS1 is the first filter of its kind designed to suppress both man-made light pollution and natural atmospheric night glow. While standard LPS filters target sodium and mercury vapor lamps, the NGS1 adds specific blocking for atmospheric Oxygen (OI) and Sodium (NaI) emission lines, for green, orange and red night glow.

    Can I use the IDAS NGS1 with my fast f/2 RASA or telephoto lens?

    Yes. The IDAS NGS1 is designed for fast optical systems. Its passband is shifted toward longer wavelengths so it passes almost all nebular emission lines when the light's incidence angle stays below 14 degrees. For the RASA 8, the Di2 format drops into the IDAS AD19.4 adapter. With camera lenses, follow the 14-degree incidence guideline in the description.

    Which IDAS NGS1 format do I need for my ZWO camera and filter drawer?

    You have two primary options for ZWO setups:

    • DZ Drop-in: This format is designed for the ZWO FD-M54-II or FD-M42-II filter drawers. It offers a larger 47mm clear aperture to minimize vignetting with full-frame sensors.
    • ZF Filter: This filter drops directly into the T-ring of ZWO cameras that have an M42 male mount and 6.5mm flange back distance, providing a filter solution without needing a separate drawer.

    Does the IDAS NGS1 block light from modern LED streetlights?

    Yes. The IDAS NGS1 is designed as a successor to conventional light pollution filters and suppresses interference from white LED lighting, in addition to traditional high- and low-pressure sodium lamps.

    Will the IDAS NGS1 improve images of comets?

    Yes, the filter is designed to pass the light of comets. It passes wavelengths corresponding to the C2 comae (the comet's head) and the CO+ ionized tails, while simultaneously suppressing the sky background from both light pollution and natural airglow.

    How do I clean my IDAS NGS1 filter without damaging the coatings?

    First, use an air blower to remove any loose dust or gritty particles. If stains remain, apply a neutral lens cleaning liquid to a lens cleaning paper and wipe gently. Do not use acidic or alkaline cleaners.

  • Brand IDAS (ICAS Enterprises, Japan)
    Coating Type Interference filter (spectral characteristics depend on the angle of incoming light)
    Available Formats & Thickness
    • 2" (M48) Mounted: M48x0.75 threaded cell, 2.0mm substrate
    • M52 Mounted: M52x0.75 threaded cell, 2.0mm substrate
    • DS Drop-in: For IDAS AD42-DS adapter, 1.1mm substrate
    • Di2 Drop-in: For IDAS AD19.4 adapter (RASA 8), 2.0mm substrate
    • DRT Drop-in: For Canon EF-EOS R & compatible adapters, 2.0mm substrate
    • DZ Drop-in: For ZWO FD-M54-II/FD-M42-II drawers, 47mm aperture, 2.0mm substrate
    • ZF (ZWO Cameras): For ZWO M42 cameras (6.5mm backfocus), 1.1mm substrate

    • IDAS NGS1 (LPS-D3) Night Glow Suppression Light Pollution Filter

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  • Contact us for warranty details.