Navigating Optolong Filters: L-eNhance, L-eXtreme, L-Ultimate, and L-Quad Enhance for Astrophotography
If you're capturing the night sky with a color camera and dealing with less-than-ideal dark skies (which, let’s be honest, is most of us), the right narrowband filter can make a world of difference. Optolong offers a range of filters—the L-eNhance, L-eXtreme, L-Ultimate, and now the L-Quad Enhance—that are favorites among astrophotographers using color cameras like the ZWO ASI183MC, ASI533MC, ASI585MC, ASI2600MC (IMX571), and QHY equivalents. Here's how they compare and when to use each one.
L-eNhance: Great All-Rounder for Nebula Imaging
What it does:
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Tri-band filter capturing H-beta, OIII, and H-alpha
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Bandwidth: ~24nm (OIII/H-beta), ~10nm (H-alpha)
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Best under: Bortle 5–7 skies
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Targets: North America Nebula, Heart Nebula, Rosette Nebula
The L-eNhance is fantastic for those starting with narrowband imaging using a one-shot color camera. It delivers natural-looking nebula colors while reducing light pollution—ideal for suburban backyard astrophotography.
? Check out the Optolong L-eNhance
L-eXtreme: Step Up the Contrast in Light-Polluted Skies
What it does:
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Dual-band filter for OIII and H-alpha
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7nm bandwidth for enhanced light pollution rejection
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Best under: Bortle 6–8 skies or during full moon nights
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Targets: Veil Nebula, Lagoon Nebula, Crescent Nebula
The L-eXtreme excels in urban environments, isolating emission lines while blocking skyglow and moonlight. It's a top choice for astrophotographers using fast optics like f/4 Newtonians or HyperStar setups.
? Check out the Optolong L-eXtreme
L-Ultimate: Ultra-Narrowband for Advanced Imaging
What it does:
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Dual-band filter with 3nm bandwidth for OIII and H-alpha
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Designed to minimize halos and maximize contrast
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Best under: Bortle 7–9 skies (high light pollution)
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Targets: Crescent Nebula, Bubble Nebula, Helix Nebula
The L-Ultimate is Optolong’s most advanced filter for one-shot color astrophotography. Its 3nm bandwidth offers unmatched contrast and detail, even under heavily light-polluted skies—perfect for imaging faint nebulae with precision.
? Check out the Optolong L-Ultimate
L-Quad Enhance: Versatile Broadband Light Pollution Suppression
What it does:
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Quad-band filter targeting H-beta, OIII, H-alpha, and SII
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Designed for broadband targets like galaxies and star clusters
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Best under: Bortle 1–7 skies
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Targets: Andromeda Galaxy (M31), Triangulum Galaxy (M33), Orion Nebula (M42), Double Cluster (NGC 869 & 884)
The L-Quad Enhance is a game-changer for broadband astrophotography. It effectively suppresses light pollution from mercury and sodium lamps, enhancing contrast and color balance in your images. With over 90% transmittance at key nebula emission lines and a near-infrared cut-off at 1000nm, it reduces IR noise and delivers clearer, more detailed images.
? Check out the Optolong L-Quad Enhance
Quick Comparison Chart
| Filter | Bandwidth | Best Conditions | Moonlight Performance | Color Balance | Price-to-Performance | Fast Optics Compatibility |
|---|---|---|---|---|---|---|
| L-eNhance | ~24nm & 10nm | Bortle 5–7 | Moderate | Natural-to-Warm | Excellent (entry-level) | Very Good (≥ f/3 recommended) |
| L-eXtreme | 7nm | Bortle 6–8 | Good | Cooler (more contrast) | Great (value performer) | Excellent (≥ f/3 recommended) |
| L-Ultimate | 3nm | Bortle 7–9 | Excellent | Very Cool (highest isolation) | Premium (pro-grade) | Good (≥ f/4 recommended) |
| L-Quad Enhance | Quad-band | Bortle 1–7 | Good | Balanced | Excellent (broadband versatility) | Excellent (≥ f/3 recommended) |
Final Thoughts: Best Filters for Color Astrophotography
Whether you're using a ZWO ASI camera or a QHY color sensor, these Optolong filters are designed to maximize your deep-sky imaging potential. The L-eNhance offers a balanced and user-friendly experience, the L-eXtreme provides high-contrast images in challenging conditions, the L-Ultimate delivers unparalleled detail under severe light pollution, and the L-Quad Enhance excels in broadband imaging, making it a versatile addition to your astrophotography toolkit.
If you're seeking the best narrowband and broadband filters for astrophotography in 2025, Optolong's lineup has you covered.
Clear skies and happy imaging!