Optolong L-Extreme Dual Narrowband Filter
Buy on Amazon
The Optolong L-Extreme is a 7nm dual narrowband filter designed for astrophotography, simultaneously passing H-Alpha and O-III wavelengths to capture rich emission nebula detail in a single exposure. It excels in light-polluted environments by aggressively blocking artificial skyglow and broadband light pollution while preserving the faint signals that matter most. Overall it offers impressive contrast and color separation at a competitive price point for a quality dual-narrowband solution.
Key Features & Specs
| Filter Type | Dual narrowband passing H-Alpha (656nm) and O-III (500nm) simultaneously at 7nm bandwidth |
|---|---|
| Size | 1.25-inch threaded format, compatible with standard eyepiece and focuser threads |
| Transmission | Greater than 90% peak transmission at target wavelengths with deep blocking of broadband light |
| Compatibility | Works with one-shot color (OSC) cameras and monochrome sensors; optimized for fast focal ratios |
| Construction | Multi-layer anti-reflection coatings on optical-grade glass with a durable anodized aluminum cell |
| Light Pollution | Effectively suppresses LP, moonlight, and artificial skyglow for suburban and urban imaging sessions |
| Use Case | Emission nebula imaging in HOO or SHO palette workflows with significant contrast and detail gains |
Best for: Amateur and intermediate astrophotographers shooting emission nebulae from light-polluted locations who want a single filter that captures both H-Alpha and O-III data efficiently with a color or monochrome camera.