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Optolong L-Enhance Filter
Optolong L-Enhance Filter

Optolong L-Enhance Filter

by Optolong
SKU OPT-13801
CA$251.00 - CA$363.00
CA$251.00
CA$251.00 - CA$363.00
CA$251.00
Price Match Policy!
  • Dual-bandpass filter isolates H-Alpha, H-Beta, and OIII emission lines
  • Peak transmission of over 90% for maximum signal
  • Blocks over 99% of light pollution across a 300-1000nm range
  • Maintains image sharpness with a λ/4 transmitted wavefront
  • Constructed from 1.85mm thick B270 optical glass
3 in stock
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  • Description
  • FAQ
  • Specifications
  • Warranty

  • Optolong L-Enhance Filter

    The Optolong L-Enhance filter is an economical, high-transmission solution for color astrophotography from light-polluted skies. This dual-bandpass filter achieves over 90% peak transmission in the critical H-Alpha, H-Beta, and Oxygen III emission lines, capturing the most important nebula data with any color camera. It simultaneously eliminates the impact of urban skyglow by blocking more than 99% of light pollution lines across a wide 300-1000nm range. The entire optical path is built on a 1.85mm B270 substrate polished to a λ/4 transmitted wavefront, ensuring your telescope's resolution is perfectly preserved.

    Dual-Bandpass Design: Over 90% Transmission in H-Alpha, H-Beta & OIII

    Unlike broadband filters that pass large sections of the spectrum, the L-Enhance isolates only the most important wavelengths for emission nebulae. By targeting H-Alpha (656nm), H-Beta (486nm), and OIII (500nm) with a peak transmission greater than 90%, it dramatically increases the contrast between your target and the sky background. This design choice prioritizes the wavelengths associated with hydrogen and oxygen—the building blocks of star formation—to deliver scientifically significant data from your color camera in a single shot.

    Light Pollution Suppression: >99% Rejection of Unwanted City Glow

    For imagers in urban or suburban locations, the primary challenge is skyglow from artificial lighting. The L-Enhance filter meets this challenge with an aggressive blocking depth of over 99% for major light pollution sources, including mercury and sodium vapor lamps. This deep blocking darkens the sky background in your images, allowing the faint, desirable light from nebulae to stand out clearly. The result is longer possible sub-exposure times and a signal-to-noise ratio that was previously only achievable from dark sites.

    Optical & Build Quality: λ/4 Wavefront on a 1.85mm B270 Substrate

    A filter should only transmit light, not distort it. The Optolong L-Enhance is built on a 1.85mm thick B270 glass substrate, polished to a surface quality of 60/40 and a parallelism of 30 arcseconds. Critically, it guarantees a transmitted wavefront of λ/4 or better, ensuring that it will not introduce aberrations or degrade the sharp stars produced by your telescope's optics. Advanced ion-assisted deposition coatings ensure these transmission characteristics are durable, scratch-resistant, and stable regardless of temperature changes during an imaging session.

    The 1-Shot-Color Solution: L-Enhance vs. Monochrome Narrowband

    While a monochrome camera with a filter wheel and separate S-II, H-Alpha, and O-III filters offers maximum data control, this approach is complex and expensive. The Optolong L-Enhance provides a streamlined and highly effective alternative for one-shot-color (OSC) cameras like DSLRs and dedicated astronomy CMOS cameras.

    • Efficiency: The L-Enhance captures two of the most important bandpasses (H-Alpha and OIII) simultaneously, dramatically reducing the total imaging time required compared to shooting each channel separately with a mono camera.
    • Simplicity: It eliminates the need for a filter wheel and the complexities of combining multiple monochrome datasets, making deep-sky imaging more accessible.
    • Cost-Effectiveness: For a fraction of the cost of a full monochrome setup, the L-Enhance unlocks the ability to shoot high-contrast nebula images from the city.

  • What makes the Optolong L-Enhance different from a standard light pollution filter?

    A standard light pollution (LPS) filter is a broadband filter that tries to notch out specific light pollution lines while passing most other light. The Optolong L-Enhance is a multi-bandpass narrowband filter. It works in reverse: it blocks almost the entire spectrum, only passing specific, narrow bands corresponding to nebula emission lines (H-Alpha, H-Beta, and OIII), resulting in much higher contrast.

    Can I use the Optolong L-Enhance filter with a monochrome camera?

    Yes, you can. While designed for color cameras, the L-Enhance works well with a monochrome camera to capture H-Alpha, H-Beta, and OIII data simultaneously for a high-quality luminance frame. This is useful for simplifying data acquisition, though you will not be able to separate the individual channels for color mapping as you would with dedicated single-bandpass filters.

    How does the Optolong L-Enhance perform on a target like the North America Nebula (NGC 7000) from the suburbs?

    The Optolong L-Enhance is exceptionally effective on emission nebulae like the North America Nebula (NGC 7000) and the nearby Pelican Nebula (IC 5070). These targets are rich in Hydrogen-Alpha, which the filter passes with over 90% transmission. From a suburban location, the filter's >99% blocking of skyglow will darken the background, revealing the intricate structures and faint extensions of the nebula that would otherwise be lost.

    Is the Optolong L-Enhance effective for imaging the Veil Nebula complex under moonlight?

    Yes. Moonlight is broadband light, and a narrowband filter like the L-Enhance is the best tool for mitigating its effects. Because the filter only passes the narrow bands of OIII and H-Alpha/H-Beta, it blocks the vast majority of moonlight. This allows you to continue imaging targets rich in those emissions, like the Veil Nebula, even during bright moonlit nights.

    Why does the Optolong L-Enhance pass H-Beta in addition to H-Alpha and OIII?

    The H-Beta emission line (486nm) is very close to the OIII lines (~500nm). The L-Enhance is designed with a wider bandpass in the blue-green part of the spectrum that includes both OIII and H-Beta. This captures more signal from objects that have strong H-Beta emission, such as the California Nebula or Horsehead Nebula, adding to the richness of the final image from a color camera.

    Will I need to refocus when using the 1.85mm Optolong L-Enhance filter?

    Yes, adding any filter into the optical path will shift the focus point. The 1.85mm thickness of the B270 glass will require a small amount of outward focus travel. It is always recommended to check and readjust focus after inserting or removing a filter.

  • Substrate Material B270
    Substrate Thickness 1.85mm
    Peak Transmission T>90%
    Blocking Range 300-1000nm
    Blocking Depth >99% at light pollution lines
    Surface Quality 60/40
    Transmitted Wavefront λ/4 RMS
    Parallelism 30s
    Available Sizes 1.25" Mounted, 2" Mounted, Clip for Canon EOS APS-C
  • Optolong 3-Year Warranty