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IMPORTANT: Our store is located in Canada. All orders that include products manufactured outside of Canada or USA will be subject to tariffs and duties, regardless of the order value. US customers are responsible for all applicable duties and tariffs, and those will be billed by the carrier, except for the Lacerta upgrade kit, for which we collect them at checkout.
Optolong LRGB, Ha, OIII & SII Filter Set

Optolong LRGB, Ha, OIII & SII Filter Set

by Optolong
SKU OPT-LRGBSHO-1.25
$665.00 - $1,009.00
$665.00
$665.00 - $1,009.00
$665.00
Price Match Policy!
  • Complete 7-filter set for monochrome astrophotography
  • Includes Luminance, Red, Green, and Blue broadband filters
  • Includes 3nm Hydrogen-alpha, Oxygen-III, and Sulphur-II narrowband filters
  • LRGB set features a gap to block 589nm sodium light pollution
  • Enables both natural color LRGB and Hubble Palette SHO imaging
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  • Description
  • FAQ
  • Specifications
  • In the Box
  • Warranty

  • Optolong LRGB, Ha, OIII & SII Filter Set

    The Optolong LRGB, Ha, OIII & SII Filter Set provides a complete 7-filter solution for advanced monochrome imaging. This comprehensive kit combines a high-contrast LRGB filter set for natural-color broadband targets with a trio of 3nm narrowband filters for isolating emission nebulae. The LRGB set is engineered with a specific gap between the green and red filters to block the primary sodium light pollution line at 589nm, while the 3nm SHO filters target the critical 656nm H-alpha and 500nm OIII emission lines for maximum signal and contrast.

    LRGB + 3nm SHO: The Complete 7-Filter Monochrome Solution

    This 7-filter set equips your monochrome camera for virtually any deep-sky object. You can capture galaxies and star clusters in true-to-life color with the LRGB filters, then switch to the 3nm narrowband filters to capture the faint, intricate structures of emission and planetary nebulae. By including both sets, Optolong eliminates the need to build a filter collection piece by piece, providing a unified system for both broadband and narrowband workflows.

    LRGB Imaging: Natural Color Balance with a 589nm Sodium Cutoff

    The Optolong LRGB filters are designed for maximum color separation and contrast. The transmission curves feature extremely high gradients to clearly differentiate color channels, while a carefully placed gap between the green and red filters blocks the prominent 589nm sodium light pollution line. This targeted rejection significantly improves color balance and makes post-processing more straightforward. Furthermore, OIII emission is allowed to pass through both the blue and green filters, ensuring high efficiency when capturing planetary nebulae in LRGB and preserving their natural teal coloration.

    3nm SHO Filters: Isolating Ha, OIII, and SII for the Hubble Palette

    For the highest possible contrast on emission nebulae, the 3nm SHO (Sulphur-II, Hydrogen-alpha, Oxygen-III) filters isolate the specific wavelengths of ionized gas while rejecting nearly all other light. This extreme narrow bandpass darkens the sky background, suppresses moonlight and artificial light pollution, and makes faint nebulosity stand out. By assigning the data from the SII, Ha, and OIII filters to the red, green, and blue channels in processing, you can create the iconic, high-contrast images made famous by the Hubble Space Telescope.

    656nm Ha & 500nm OIII: Capturing the Universe's Primary Emission Lines

    The 3nm H-alpha filter is centered at 656nm, capturing the dominant wavelength emitted by vast star-forming regions across the Milky Way. The 3nm OIII filter is centered at 500nm to capture the strong blue-green light from doubly ionized oxygen, characteristic of planetary nebulae and supernova remnants. Used together, these two filters can produce stunning bicolor images that reveal incredible structural detail while maintaining a natural, scientifically relevant color palette.

  • What is the main advantage of this Optolong 7-filter set?

    The primary advantage is its completeness. This single set provides all the necessary filters for the two main types of monochrome deep-sky imaging: LRGB for broadband targets like galaxies and star clusters, and 3nm SHO narrowband for emission nebulae. This allows you to tackle any object without needing to purchase additional filters.

    Why is the 3nm bandpass on the Optolong SHO filters important?

    A 3nm bandpass is extremely narrow, meaning it only allows a tiny sliver of the light spectrum to pass through to the sensor. This provides exceptional rejection of light pollution from city lights, moonlight, and natural skyglow. The result is a much darker background and significantly higher contrast on faint nebulae compared to wider 6nm or 7nm filters.

    How would I use this Optolong filter set to image the Orion Nebula (M42)?

    M42 is a complex object with both bright stars and extensive nebulosity. A great approach is a hybrid one:

    • Use the H-alpha and OIII filters to capture long exposures of the faint, sprawling nebulosity with high contrast.
    • Use the LRGB filters to capture a series of shorter exposures to resolve the bright Trapezium star cluster at the core without overexposing it.
    • In post-processing, you can combine the data from all filters to create a final image with a full dynamic range and rich detail.

    Which filters from the Optolong set are best for the Andromeda Galaxy (M31)?

    The Andromeda Galaxy is a broadband target, meaning it shines across the visible spectrum like a star cluster. For M31, you would primarily use the LRGB filters to capture its bright core, spiral arms, and dust lanes in natural color. You can also use the H-alpha filter to take very long exposures, which will reveal the small, pinkish star-forming regions (HII regions) embedded within its spiral arms.

    What is the "Hubble Palette" and how does this Optolong set enable it?

    The Hubble Palette is a false-color imaging technique used to differentiate structures in emission nebulae. It involves mapping data from the three narrowband filters to the RGB channels of a color image:

    • Sulphur-II (SII) data is mapped to the Red channel.
    • Hydrogen-alpha (Ha) data is mapped to the Green channel.
    • Oxygen-III (OIII) data is mapped to the Blue channel.

    This Optolong set includes all three required SII, Ha, and OIII filters, allowing you to create these vibrant and detailed images.

    What does the gap between the green and red Optolong LRGB filters do?

    The gap is a design feature for light pollution suppression. It is specifically placed to block the transmission of light around the 589nm wavelength. This is the primary emission line of sodium-vapor streetlights, a major source of urban skyglow. By blocking this line, the filters improve color separation and produce a cleaner image from suburban or city locations.

  • Filter Count 7 (Luminance, Red, Green, Blue, Ha, OIII, SII)
    Narrowband Bandpass 3nm
    H-Alpha Center Wavelength 656nm
    OIII Center Wavelength 500nm
    Light Pollution Rejection Notch at 589nm (Sodium Line)
    Available Formats 1.25" Mounted, 36mm Round Unmounted, 2" Mounted

    • Luminance (L) Filter

      × 1

    • Red (R) Filter

      × 1

    • Green (G) Filter

      × 1

    • Blue (B) Filter

      × 1

    • 3nm H-Alpha (Ha) Filter

      × 1

    • 3nm Oxygen-III (OIII) Filter

      × 1

    • 3nm Sulphur-II (SII) Filter

      × 1

  • Optolong 3-Year Warranty