Promotional price for official launch, offer valid Sept 25, 2025- Oct 25, 2025
Optolong L-Synergy is a dual 7nm narrowband filter compatible with DSLR cameras, color CMOS sensors, and CCD cameras, supporting telescope systems with F-ratio of F3.3 or above (slower system）. Its key advantage lies in enabling astrophotography amateurs to capture exceptionally detailed emission nebulae even in light-polluted environments. it has been optimized to minimize bright star halos while isolating all emission lines except SII and OIII, achieving maximum effective transmission.
Why do we make a L-Synergy filter?
The core innovation of L-Synergy filters lies not in a single functional breakthrough, but rather in the precise combination of traditional dual-narrowband (Ha & OIII) technology—specifically tailored for color camera users. By adopting a dual-filter setup of "Ha & OIII + SII & OIII", it overcomes the inherent limitations of color cameras in narrowband astrophotography. With L-Synergy, users can achieve Hubble Palette-style deep-sky images comparable to those captured by monochrome SHO (SII/Ha/OIII) systems—without switching to a monochrome camera or purchasing additional SHO filters.
This solution delivers high-quality results with minimal investment, making professional-level narrowband imaging accessible to all.
Optolong L-Synergy
Opotlong L-Synergy is a dual 7nm narrowband filter compatible with DSLR cameras, color CMOS sensors, and CCD cameras, supporting telescope systems with F-ratio of F3.3 or above (slower system）. Its key advantage lies in enabling astrophotography amateurs to capture exceptionally detailed emission nebulae even in light-polluted environments.
After years of technical refinement, it has been optimized to minimize bright star halos while isolating all emission lines except SII and OIII, achieving maximum effective transmission.
Key Features:
Optolong L-Synergy's advantage lies in its selective transmission of only the nebula emission lines OIII (500.7nm) and SII (672.4nm), while blocking all other light-polluting emission lines. This ensures that only the signals from oxygen and sulfur elements are captured during imaging, resulting in a darker sky background and significantly enhanced contrast and signal-to-noise ratio (SNR) between nebulae.
Even in heavily light-polluted areas, this filter selectively transmits nebula emission lines while filtering out light pollution, ultimately eliminating its impact on astrophotography.
Optical Design
By analyzing the spectral characteristics of both celestial emission lines and light pollution, L-Synergy selectively preserves the SII and OIII nebula colors while filtering out the majority of light pollution. Specifically designed and optically optimized, L-Synergy maintains consistently high transmission across both SII and OIII bands. This ensures users can precisely capture the target nebula emissions, delivering optimal astrophotography results.
*We will continue to optimize the product based on test results. This curve does not represent final product specifications.
How to read the chart?
▲The horizontal axis is the Wavelength in Nanometers(nm).
▲The vertical axis is transmission in %.
Coating Technology
- Multi-layers anti-reflection coating
- Non-cementing optical substrate coating
- Optolong filter adopts precision coating based on Ion-assisted deposition coating technology for durability and resistance to scratching, as well as stability on CWL(central wavelength) no deviation affected by temperature change.
- Planetary rotation system offers precision and homogeneity of coatings ensuring high value on transmission of pass-band and Optical density of off-band.
| Specification | |
| 2" (M48×0.75) |
Packing Style
Outer Box: silve box
Plastic Box: PP material
Lining: imported high pressure white EVA material
6. L-Synergy Filter Performance
WR134 in the Cygnus constellation © Gianni Lacroce
Test with the new Optolong L-sinergy filter, a 7nm S2 O3 dual-band filter, and I have to say I really liked it.
I chose to photograph WR134 in the constellation Cygnus.
Having shot in monochrome, which usually results in a significant amount of signal with an H-alpha filter, the O3 is there, but sometimes I have to integrate a lot to bring it out; the S2 isn't there at all. So I thought, ‘There won't be all that much signal; to take a decent photo, I'll have to integrate a lot,’ and that's why I took 200 5-minute shots.
Once I'd processed the photo, I found it came out of the WBPP without gradients or halos, but above all, bicolour, meaning full of S2 and lots and lots of O3, and I find this wonderful. I didn't have to do anything else in processing except stretch the image, balance contrast, highlights, and tones to customise it a bit, but in the end, it was already like this in the raw file.
This filter greatly simplifies post-production.
I'll also show you the Starless Nebula to help you understand the signal and the O3 it produces.
More shots of this new filter will follow soon.
EQUIPMENT
Imaging Telescope: Newton Tecnosky Carbon 200
Imaing CameraZwo Asi 2600 duo
Mount: Zwo Am5
Optolong L-Synergy filters
PHOTOS
temp 0 with dark, flat and darkflat
200 x 300s
PROCESSING
Pixinsight
Photoshop
- Opens in a new window.