GALAXY & NEBULA BOOSTER FILTER (OIII + H-ALPHA + NIR)

IDAS GNB

The world's first Galaxy & Nebula Booster.
Blocks urban light pollution while simultaneously delivering near-infrared (NIR) galactic starlight and visible nebular emissions to color sensors.

IDAS GNB Filter
*IDAS GNB (Standard M48 mount) filter appearance. World-unique hybrid optical design passing near-infrared (NIR) and visible emission lines (OIII & Hα).

Simultaneous Urban Galaxy & Nebula Imaging via NIR + Dual-Band Design

When imaging galaxies from urban or suburban skies, harsh white LED light pollution washes out faint spiral arms and dust lanes. Conversely, conventional dual-narrowband nebula filters block the entire continuous spectrum outside Hα and OIII, extinguishing the broadband starlight of galaxies.

The IDAS GNB (Galaxy & Nebula Booster) was engineered to solve this fundamental dilemma. By opening the pollution-free near-infrared (NIR: 680nm–900nm+) window where white LEDs emit virtually no light, while simultaneously passing narrowband OIII (500.7nm) and Hα (656.3nm), GNB captures both galactic spiral structures and vibrant HII regions in a single exposure.

Exploiting the White-LED Blind Spot in Near-Infrared (NIR)

Modern urban white LED streetlights flood the visible spectrum but emit almost no energy in the near-infrared region above 680nm. GNB unlocks this clean NIR window, allowing countless stars within galaxies to be recorded with high contrast even from light-polluted backyards.

💡 From Acclaimed Astrophotographer AstroBlender (Cody): “The GNB completely rewrote the rules for galaxy imaging under light pollution. Seeing the delicate spiral arms and blazing red HII regions of M33 pop out in a single session from an urban balcony is nothing short of mind-blowing.”

Optical Mechanism & Spectral Transmission Characteristics

* Hybrid Transmission of Visible Emission Lines (OIII & Hα) + Near-Infrared (NIR)

Far more than a simple IR-pass filter, GNB steeply passes the primary visible nebular lines of OIII (blue-green) and Hα (red). On targets like the Triangulum Galaxy (M33) and Cigar Galaxy (M82), GNB simultaneously reveals star-forming HII knots and ionized gas filaments alongside the continuous galactic core and arms.

* Unleashing the High NIR Quantum Efficiency of Modern BSI CMOS Sensors

Modern back-illuminated (BSI) color CMOS sensors — such as the Sony IMX585, IMX664, and IMX294 — feature dramatically enhanced quantum efficiency (QE) in the near-infrared band. GNB harnesses 100% of this NIR sensitivity to deliver extraordinary signal-to-noise ratio in both deep-sky astrophotography and Electronically Assisted Astronomy (EAA).

IDAS GNB Official Spectral Transmittance & IMX294 Sensor QE

* Official IDAS GNB spectral transmittance curve overlaid with Sony IMX294 quantum efficiency (QE). Combines narrowband OIII and Hα with a wide, pollution-free NIR passband.

GNB Filter 3 Key Strengths

1 Opens the near-infrared (NIR) window where white LEDs emit no light, capturing galactic spiral structures with high contrast from urban skies.
2 Combines OIII and Hα dual-narrowband passbands to vividly render red HII regions and emission nebulae simultaneously.
3 Pairs with high-NIR-sensitivity BSI color CMOS sensors (IMX585, IMX294, etc.) for dramatic results in both long-exposure imaging and live EAA stacking.
💡 Recommended Cameras & Selection Guidelines for GNB
1. Back-Illuminated (BSI) High-NIR-Sensitivity CMOS Sensors Modern BSI sensors such as the Sony IMX585, IMX664, and IMX294 maintain high quantum efficiency up to ~850nm. Cooled and uncooled color cameras equipped with these sensors achieve the most dramatic boost. (Recommended: ZWO ASI585MC Pro / ASI294MC Pro, Player One Uranus-C Pro, QHY585C, etc.)
2. [Important] Camera Must Have an AR Clear Protective Window If your camera has a built-in UV/IR-cut protective window in front of the sensor, the near-infrared starlight passed by GNB will be blocked right before reaching the sensor. Always use a camera equipped with an AR (anti-reflection) clear protective glass window.
3. Color Calibration & Electronically Assisted Astronomy (EAA) Because near-infrared light excites all RGB channels on color sensors, applying Spectrophotometric Color Calibration (SPCC) in PixInsight or standard channel balancing harmonizes vibrant red/cyan nebular emissions with natural galactic starlight. In live EAA stacking (SharpCap, etc.), galactic spiral arms emerge on screen within seconds even from city skies.

Specifications & Optical Characteristics

Filter Type Galaxy & Nebula Booster Filter (Visible Dual-Band + Near-Infrared Hybrid)
Primary Passbands OIII (500.7nm) / H-alpha (656.3nm) / Near-Infrared (NIR 680nm–900nm+)
Optical Design Interference Reflection Filter (Engineered for incident-angle blueshift compensation)
Substrate & Coating 2.0mm Optically Polished Glass + Durable Ion-Assisted Deposition (IAD) Multi-Layer Coating
Available Mount Sizes M48 (48ST2), M42 (OL7.5), M54 (OL7.5), DZ (for ZWO Drawer), DRT (for Canon EF-EOS R), CA (for EOS APS-C)
Manufacturing & QA Made in Japan (ICAS Enterprises Co., Ltd. Optics Division), Individual Spectral Test Report Included

Hands-On Video Review

IDAS GNB Review Video
►

In-depth hands-on review of the IDAS GNB by renowned astrophotographer AstroBlender (Cody).
Demonstrates galaxy and emission nebula imaging under urban light pollution and compares color balance across filters.

Watch Review on YouTube ↗

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🌐 Worldwide Availability: For optimal regional pricing and fast local shipping, order via our Authorized Dealers (USA / Europe / Asia) ↗. Overseas orders are also accepted via our authorized shop on BASE (international shipping & handling apply).

💡 Purchase Information & Authorized Dealers

IDAS products are available through our authorized domestic online shop (BASE), as well as authorized astronomical telescope specialty dealers worldwide. For physical demonstrations, mounting consultations, or store points, please visit your local authorized dealer.

View Authorized Dealers ↗