Optolong L1 L-Quad & L-Para Enhence Filter Set
L1 Dual -Combo Set includes：one L-Quad Enhance Filter and one L-Para L-Quad Enhance Filter：Quad bandpass broadband filter , This filter provides better color balance while improving resistance of light pollution. It is suitable for a wide range of imaging targets, including continuous spectrum objects (RGB) such as nebulae, galaxies, and star clusters. This filter maximizes the preservation of RGB color balance in broadband spectrum targets like nebulae and galaxies, effectively improving con
Quad bandpass broadband filter , This filter provides better color balance while improving resistance of light pollution. It is suitable for a wide range of imaging targets, including continuous spectrum objects (RGB) such as nebulae, galaxies, and star clusters. This filter maximizes the preservation of RGB color balance in broadband spectrum targets like nebulae and galaxies, effectively improving contrast and detail to render subjects more vivid and three-dimensional.
A dual narrowband 10nm filter ,in systems with a focal ratio of F2 and above, the transmittance of nebula emission lines OIII and Ha exceed 85%, with excellent contrast and Anti-Halo characteristics . This filter suitable for all telescope systems, adaptable to fast optics (focal ratios of F2, F2.8, F3.2, F4) as well as various standard/normal focal ratio telescopes. Ideal for capturing Hα & OIII signals in celestial objects, this filter enhances image contrast and reveals richer details in Hα & OIII emissions.
1+1>2 features
“Broadband + Narrowband” synergy engineered for precision and colour fidelity,achieves precise signal capture and color optimization for astrophotography
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L-Quad Enhance Filter: Quad bandpass broadband filter captures the RGB signals of celestial targets
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L-Para : Dual narrowband 10nm filter selectively acquires Hα and OIII emission lines, revealing fine filamentary structures and the detailed morphology of ionised gas in deep-sky objects. After post-processing,photographers can effortlessly obtain fused images combining RGB with Hα & OIII data. This "Broadband-Narrowband Synergy" solution delivers more vibrant color rendition while accentuating subtle signal details, unlocking innovative approaches for astrophotography and enhancing the creative possibilities of color camera imaging. It pioneers new artistic dimensions, transforming the deep-sky photography process into a more technically engaging and visually rewarding experience.
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.
Technical Specifications
L-Quad Enhance 2"
| Specification |
Value |
| Substrate |
B270 |
| Thickness |
1.85 mm |
| Peak Transmission (Tpeak) |
T > 90% |
| Blocking Range |
300 – 1000 nm |
| Blocking Depth |
Light pollution line blocking > 99% |
| Surface Quality |
60/40 |
| Transmitted Wavefront (RMS) |
λ/4 |
| Parallelism |
30″ |
L-Para 2"
| Feature |
Info |
| Broad Compatibility |
Works with all telescope systems, including fast optics (F2–F4) |
| Light Pollution Resistance |
Blocks mercury, sodium, LED lines; effective under Bortle 1–7 skies |
| High Transmission Rate |
>85% for OIII & Hα (at F2 and above) |
| Excellent Contrast |
High nebula transmission + strong light pollution cut-off |
| Anti-Halo Characteristics |
Optimized design, tested for improved anti-halo on bright stars |
How to read the chart?
▲The horizontal axis is the Wavelength in Nanometers(nm).
▲The vertical axis is transmission in %.
| The Major Emission Lines of Nebulae |
The Major Emission Lines of Artificial Light Pollution |
| H-α 656.3 nm H-β 486.1 nm |
Hg 435.8 nm 546.1 nm 577 nm 578.1 nm |
| OIII 495.9 nm OIII 500.7 nm |
Na 598 nm 589.6 nm 615.4 nm 616.1 nm |
In the Box
- L-Quad Enhence Filter - 2"
- L-Para Filter - 2"
Manuals & Warranty
Optolong Warranty
