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Explore Scientific Nebula Filter S-II 2-inch 12nm
Explore Scientific Nebula Filter S-II 2-inch 12nm
Explore Scientific Nebula Filter S-II 2-inch 12nm
Explore Scientific Nebula Filter S-II 2-inch 12nm

Explore Scientific Nebula Filter S-II 2-inch 12nm

by Explore Scientific
SKU ES-310110
CA$350.00 - CA$350.00
CA$350.00
CA$350.00 - CA$350.00
CA$350.00
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  • Isolates the 672nm Sulfur-II (S-II) emission line
  • 12nm bandpass for high-contrast views
  • 2-inch filter size with standard threads
  • Blocks light pollution for visual and photographic use
  • Includes individual test report for quality assurance
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  • Description
  • FAQ
  • Specifications
  • In the Box
  • Warranty

  • Explore Scientific Nebula Filter S-II 2-inch 12nm

    The Explore Scientific Nebula Filter S-II 2-inch 12nm targets the specific 672nm wavelength of ionized sulfur, using a tight 12nm bandpass to isolate faint nebula emissions from a light-polluted sky. This high degree of filtration dramatically increases contrast, revealing celestial structures that are otherwise lost to skyglow from artificial lighting.

    Targeting the 672nm S-II Line with a 12nm Bandpass

    This filter is engineered to transmit light only within a 12nm window centered on the 672nm wavelength. This spectral line corresponds to the light emitted by ionized sulfur (S-II), a key element found in many emission nebulae and supernova remnants. By blocking nearly all other wavelengths, the filter effectively darkens the sky background, making the faint signal from the nebula stand out in sharp relief.

    Astrophotography & Visual Use: Revealing Structures at 672nm

    For visual observers, the S-II filter can make the difference between seeing a faint smudge and resolving intricate detail in objects like the Lagoon Nebula (M8) or the Eagle Nebula (M16). In astrophotography, the S-II signal is critical for creating detailed false-color images. It often highlights shock fronts and outer structures that are not as prominent in other wavelengths, adding a crucial layer of depth and information to your final image.

    S-II vs. H-alpha and O-III: Building the 3-Filter Hubble Palette

    While an H-alpha filter captures the dominant hydrogen signal, an S-II filter provides a vital third channel for narrowband imaging, alongside Oxygen-III. This trio (S-II, H-alpha, O-III) forms the basis of the "Hubble Palette" (SHO), allowing astrophotographers to assign each element to a different color channel (Red, Green, Blue) to produce vibrant, data-rich images. The 12nm bandpass is a versatile choice, offering a significant contrast boost for imagers while remaining wide enough to provide a reasonably bright image for visual observers.

    Quality Assurance: An Individual Test Report for Every 2-inch Filter

    Explore Scientific ensures that each filter meets its design specifications by including an individual test report with every unit. This certificate verifies the filter's specific transmission curve, confirming that its central wavelength and 12nm bandpass are precisely manufactured. This guarantee of optical integrity means you can be confident you are capturing the exact spectral data you need for serious observation and imaging.

  • What is the Explore Scientific S-II 12nm filter primarily used for?

    The Explore Scientific S-II 12nm filter is designed to isolate the 672nm wavelength of light emitted by ionized sulfur. It is used by both visual observers and astrophotographers to drastically increase the contrast of emission nebulae, planetary nebulae, and supernova remnants, especially from light-polluted locations.

    Can I use the S-II 2-inch filter for visual observing?

    Yes, while S-II is often considered an astrophotography filter, the 12nm bandpass is wide enough to provide a usable image for visual observation in larger aperture telescopes. It can reveal structures in certain nebulae that are faint or invisible even with UHC or O-III filters. However, the view will be significantly dimmer than without a filter, so it is best used on bright emission nebulae.

    How does this S-II 12nm filter help when imaging the Eagle Nebula (M16) from a light-polluted suburb?

    The Eagle Nebula (M16) is rich in ionized sulfur, particularly in the famous "Pillars of Creation." From a light-polluted area, the S-II 12nm filter will reject the broad-spectrum glow from city lights while passing the specific 672nm light from the nebula. This dramatically darkens the sky background in your images, increases the signal-to-noise ratio, and allows you to capture the delicate S-II details in the pillars and surrounding gas clouds.

    I have an f/10 SCT. Is the 12nm bandpass on this S-II filter a good choice?

    Yes, a 12nm bandpass is an excellent choice for an f/10 Schmidt-Cassegrain Telescope. Slower optical systems experience less band-shifting with interference filters, ensuring the 672nm S-II line remains centered in the filter's passband. The 12nm width provides a strong contrast boost without being so restrictive that it requires extremely long sub-exposures, making it a well-balanced option for typical SCT imaging setups.

    Do I need an S-II filter if I already have an H-alpha filter?

    For monochrome astrophotography, an S-II filter is a critical addition to an H-alpha filter. While H-alpha captures the strongest overall signal, S-II reveals different structural details. Combining S-II, H-alpha, and O-III data allows you to create full false-color "Hubble Palette" images (SHO), which provide far more depth and information than H-alpha alone.

    What does the individual test report for the S-II 12nm filter show?

    The included test report is a spectrophotometer reading of your specific filter. It graphically displays the light transmission across the spectrum, providing verification of two key specs:

    • Central Wavelength: Confirms the filter is centered precisely at or near 672nm.
    • Bandpass: Confirms the Full-Width at Half-Maximum (FWHM) is 12nm as specified.
    This ensures you receive a filter that performs exactly as advertised.
  • Filter Type Narrowband S-II (Ionized Sulfur)
    Central Wavelength 672nm
    Bandpass (FWHM) 12nm
    Size 2-inch
    Primary Use Astrophotography, Visual Observation

    • Nebula Filter S-II 2-inch 12nm

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    • Protective Case

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    • Individual Test Report

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