Optolong L-Ultimate Ha/OIII 3nm Filter

Name: Optolong L-Ultimate Ha/OIII 3nm Filter
Brand: Optolong
Price: 289.0 USD
Availability: InStock

by Optolong

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$289.00 USD - $389.00 USD

$289.00

$289.00 USD - $389.00 USD

$289.00 USD

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Extreme light pollution reduction
Ultra narrow 3nm bandpasses
Isolates key H-alpha and OIII emissions
Provides superior contrast and a darker sky background
Minimizes star halos on bright stars

Availability:

Backordered
Contact us to know when we will receive our next ones!

Availability:

Backordered
Contact us to know when we will receive our next ones!

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Description
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In the Box

Optolong L-Ultimate Overview

The Optolong L-Ultimate is a high-performance dual-bandpass filter explicitly designed for astrophotographers who use color cameras (DSLR, CMOS, or CCD) to capture emission nebulae. With its ultra-narrow 3 nm bandpasses centered on the key nebula emission lines— O III at 500.7 nm and H-alpha at 656.3 nm —the filter lets through only nebular light and blocks all unwanted street lights and atmospheric emissions. This dramatically darkens the sky background and significantly enhances image contrast and signal-to-noise ratio. The L-Ultimate is one of the most effective tools available for cutting through extreme light pollution to capture stunning images of emission nebulae.

One-Stack Dual Wavelength Capture

Unlike monochrome setups that require multiple filters and long exposure nights, this filter captures both H-alpha and OIII signals in a single exposure when paired with color cameras. This saves you time and simplifies your setup, allowing you to achieve results rivaling those from a monochrome camera with separate narrowband filters.

Sharper Stars, Minimal Halo Effects

The L-Ultimate is engineered to greatly reduce halos around bright stars —a common issue with wider band filters—offering crisper, cleaner stars in your images. By blocking out all light except for the critical H-alpha and OIII emission lines with ultra narrow 3nm bandpasses, the filter maximizes the signal from the nebulae while minimizing the noise from the sky background, leading to a cleaner final image that requires less post-processing.
L-Ultimate vs. L-eNhance & L-eXtreme

The L-Ultimate is a dual 3 nm ultra-narrowband filter that transmits only the H-alpha (656.3 nm) and O III (500.7 nm) emission lines. Compared to the L-eXtreme (dual 7 nm) and L-eNhance (H-alpha 10 nm + O III/H-beta 24 nm), the L-Ultimate offers several advantages:
- Darker sky background – its tighter 3 nm bandpass blocks nearly all light pollution and unwanted wavelengths.
- Higher contrast and finer details – faint nebular structures stand out more clearly.
- Superior star control – greatly reduces halos and star bloat compared to the L-eXtreme and especially the L-eNhance.
- Optimized color preservation – maintains the natural balance of H-alpha reds and O III blues/greens.
In short:
- L-eNhance – entry-level light pollution filter, wider bandpasses, captures more broadband light but with more sky glow.
- L-eXtreme – tighter control (7 nm), stronger light pollution reduction, but still allows more background light than the L-Ultimate.
- L-Ultimate – most advanced option, with the narrowest bandpass for maximum contrast, cleanest stars, and the best performance in heavy light pollution or under bright moonlight.
UV and IR Blocking

The L-Ultimate filter's design inherently suppresses ultraviolet (UV) and infrared (IR) wavelengths. This feature simplifies the imaging workflow by eliminating the need for a separate IR-cut filter. This comprehensive blocking capability ensures that extraneous light from both ends of the visible spectrum does not interfere with the final image.

Material	Schott B270 optical glass
Thickness	1.85mm
Filter Cell Height	4.8mm without male thread, 6.8mm with thread
FWHM	H-alpha 3nm, OIII 3nm
Surface Quality	60/40 (Refer to MIL-O-13830)
Optical Polish	Fine-optically polished to ensure accurate 1/4 wavefront and < 30 seconds parallelism
Transmission	High transmission at H-alpha (656.3nm) and OIII (500.7nm)
Blocking	OD4 (300-1000nm), blocking all major artificial light pollution lines

- L-Ultimate filter
  
  × 1
- Plastic Filter Case
  
  × 1

Optolong L-Ultimate Ha/OIII 3nm Filter

Optolong L-Ultimate Overview

One-Stack Dual Wavelength Capture

Sharper Stars, Minimal Halo Effects

L-Ultimate vs. L-eNhance & L-eXtreme

UV and IR Blocking

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Optolong L-Ultimate Ha/OIII 3nm Filter

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Optolong L-Ultimate Ha/OIII 3nm Filter

Description

Optolong L-Ultimate Overview

One-Stack Dual Wavelength Capture

Sharper Stars, Minimal Halo Effects

L-Ultimate vs. L-eNhance & L-eXtreme

UV and IR Blocking

You may also like

ZWO Filter Drawer V2 - M42

Optolong L-Extreme Filter

Telegizmos 365 Series Cover for SCT/Mak/RC/Newtonian on EQ Mount

Optolong L-Quad Enhance Filter

Optolong L-Pro Filter

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Country