Optolong L-Synergy Dual 7nm Narrowband Filter
Unlock the hidden colours of emission nebulae with the Optolong L-Synergy Dual 7nm Narrowband Filter.
Designed specifically for deep-sky astrophotography with DSLR, colour CMOS and CCD cameras, the Optolong L-Synergy is a specialised dual-narrowband filter that selectively captures the Sulfur-II (SII) and Oxygen-III (OIII) emission lines while suppressing unwanted background light.
With its 7nm narrowband transmission, L-Synergy significantly improves contrast between faint nebular structures and the sky background, making it particularly useful for astrophotography from light-polluted locations.
Capture SII and OIII with a Colour Camera
Traditional Hubble Palette imaging generally requires a monochrome astronomy camera together with separate SII, H-alpha and OIII filters. The L-Synergy takes a different approach by combining SII and OIII narrowband transmission in a single filter.
This allows colour-camera astrophotographers to record strong SII and OIII signals in the same imaging session and produce distinctive bicolour and Hubble-palette-style deep-sky images, without the need for a dedicated monochrome camera or multiple narrowband filters.
Excellent Contrast Under Light-Polluted Skies
Urban and suburban skies contain significant amounts of unwanted artificial and natural background light. The L-Synergy's narrow 7nm bandpasses selectively transmit the targeted nebular emission lines while blocking much of the surrounding unwanted light.
The result is:
Darker and cleaner sky backgrounds
Increased contrast in emission nebulae
Improved signal-to-noise ratio
Better visibility of faint nebular structures
Enhanced colour separation in astrophotography
This makes the filter particularly useful for astrophotographers who cannot always image from a dark-sky location.
Optimised for SII and OIII Emission
The L-Synergy selectively transmits the principal OIII emission line at 500.7nm and SII emission at approximately 672.4nm. By concentrating the camera's sensitivity on these important nebular wavelengths, the filter helps reveal structures and colours that can otherwise be overwhelmed by the sky background.
Designed for Modern Astrophotography
The filter is compatible with:
DSLR cameras
Colour CMOS astronomy cameras
CCD cameras
It is designed for telescope systems with F/3.3 and slower focal ratios, making it suitable for a wide range of commonly used astrophotography telescopes and optical systems.
Advanced Optical Coatings
Optolong uses a precision ion-assisted deposition coating process with multiple anti-reflection coating layers. The coating technology is designed to provide high transmission in the desired passbands while maintaining durability and resistance to scratching.
The coating process also provides good stability of the filter's central wavelength against temperature variations.
Minimise Unwanted Star Halos
L-Synergy has been optically refined with the aim of reducing bright-star halo effects while maintaining efficient transmission of the targeted nebular wavelengths. This helps produce cleaner-looking astrophotographs with better-defined stars and nebular structures.
Ideal Targets
The Optolong L-Synergy is particularly well suited to emission nebulae rich in SII and OIII emission, including:
Emission nebulae
Supernova remnants
Planetary nebulae
Large and faint deep-sky nebular structures
HII regions
Complex nebulae containing strong OIII and SII emissions
Key Features
Dual-band SII + OIII narrowband filter
7nm narrowband bandwidth
Designed for colour DSLR, colour CMOS and CCD cameras
Suitable for F/3.3 and slower optical systems
Selectively transmits OIII 500.7nm
Selectively transmits SII 672.4nm
Suppresses unwanted background and light pollution
Enhances nebular contrast and signal-to-noise ratio
Enables distinctive bicolour / Hubble-palette-style imaging
Optimised to reduce bright-star halo effects
Multi-layer anti-reflection coating
Ion-assisted deposition coating technology
Durable optical coating
2-inch M48 × 0.75 filter thread