Optolong L-Synergy 2" SII/OIII 7nm Dual Band Filter
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The Optolong L-Synergy 2" SII/OIII 7nm Dual Band Filter is designed for astrophotographers who want to capture high-quality images even under heavy light pollution or bright moonlight. With its 7nm bandwidth, it provides excellent transmission at the spectral lines SII (672.4nm) and OIII (500.7nm), while efficiently blocking unwanted wavelengths.
The 2-inch version is ideal for telescopes equipped with 2" focusers, ensuring wide compatibility with optical systems and both color and monochrome sensors. Precision construction guarantees stable performance and uniform transmission.
Benefits for Astrophotography
This dual band narrowband filter captures the emissions of ionized sulfur (SII) and doubly ionized oxygen (OIII) simultaneously. A single exposure records both spectral components, optimizing imaging time and improving color fidelity.
Perfect for photographing nebulae such as the Veil Nebula, Crab Nebula, M76, and other supernova remnants or planetary nebulae. When combined with Optolong L-eXtreme (Ha/OIII) or L-Ultimate, it allows for spectacular and scientifically accurate images in the Hubble Palette style, even from suburban skies.
Technical Specifications
| Type | Dual band narrowband filter |
| Size | 2" (50.8 mm) |
| Bandwidth | 7nm (SII 672.4nm, OIII 500.7nm) |
| Transmission | Very high at both channels, efficient out-of-band blocking |
| Light Pollution Reduction | Effective against artificial lights and moonlight |
| Compatibility | Telescopes with 2" focusers, color and monochrome sensors |
| Ideal Use | Imaging emission nebulae (SII/OIII) |
| Recommended Combinations | L-eXtreme (Ha/OIII), L-Ultimate for Hubble Palette |