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Optolong Sulfur II / S-II Narrowband (12nm) Nebula CCD Filter - 1.25"

Our Price: $129.00
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In stock (3 Available)
Ships by Next Business Day
Our Product ID: OFIL-OL-SII12-1.25in
Manufacturer SKU: Q1SII012403Y
Item Can Ship: Worldwide
Optolong Sulfur II / S-II Narrowband (12nm) Nebula CCD Filter

More Views

  • Optolong Sulfur II / S-II Narrowband (12nm) Nebula CCD Filter
  • Optolong Sulfur II / S-II Narrowband (12nm) Nebula CCD Filter - Representative Transmission Curve

Product Details

A. About Optolong's S-II (12nm) FIlter

The Optolong S-II (Sulfur-III) narrowband filter is designed to improve the visibility of various deep sky objects. It does this by:

  • Selectively reducing the transmission of wavelengths of light pollutants, specifically those produced by artificial lighting (including mercury vapor lamps, both high & low pressure sodium vapor lights, and the unwanted natural light caused by neutral oxygen emission in our atmosphere (i.e. skyglow)).
  • Allowing 12nm bandwidth of light centered on a wavelength of 672nm to pass through, which corresponds to SII emission lines.

B. Main Uses and Performance

  • Use with H-alpha and OIII-CCD narrowband filters (SHO Set) for tricolor CCD astrophotography.
  • Narrowband imaging with SHO set can be done with the moon up in heavy light pollution, so your equipment is not sitting dormant for several weeks.
  • Hubble look of images can be made by the combination of H-alpha, OIII-CCD and SII-CCD images, such as the famous "Pillars of Creation" (M16 Eagle Nebula).

C. Spectral Curve Transmission Characteristics

  • 90% transmission at SII line 672nm
  • 0.1% transmission of major transmission lines of artificial light pollution:
    • Hg (Mercury) at 435.8nm, 546.1nm, 577nm, and 578.1nm.
    • Na (Sodium) at 598nm, 589.6nm, 615.4nm, and 616.1nm.
  • It also blocks out infrared wavelengths (700-1100nm) so a separate IR cut-off filter is not required for imaging applications.

D. Technical Specifications

  • Both surfaces are fine optically polished, accurate to 1/4 wavelength or better, and parallel to within 30 seconds or arc.
  • 2mm thick Schott B270 optical glass substrate material.
  • Very high surface quality of 60/40 or better (US Military Spec MIL-O-13830).

E. Optical Coating Specifications

  • Multi layer anti-reflection coated.
  • Non-cementing optical substrate coating.
  • Electron-beam gun evaporation with Ion-assisted deposition coating technology for durability and resistance to scratching, as well as stability on CWL (central wavelength) so that there is no deviation due to temperature changes during use.
  • Precise and homogeneous coatings ensure high values of desired passband and blocking of unwanted offband.
  • Every single filter is tested and passed by Optolong before shipping to dealers.

F. Other

  • 1.25" astronomy filter with standard M28.5x0.6 male filter thread (no female thread, so it cannot be stacked with other filters).
  • Ultra-thin filter cell to minimize vignetting; clear optical aperture of 26mm.
  • Precision CNC-machined metal filter cell with sand blasted black anodized finish, anti-reflection treatment, and laser engraving.
  • High quality protective plastic storage case.

WARNING: Optolong filters are not designed for direct solar observation. NEVER use these filters for observing the Sun, or permanent eye and equipment damage will result.

Additional Information

About Optolong

While Optolong is a relative newcomer to the astronomy industry, they are no strangers to optics and filters. Optolong is a division of Yulong Optics Company, a high tech company specializing in optical filter design and production. Their products include bandpass filters, flourescence filters, edge filters, longpass and shortpass filters, beam splitters, anti-reflection coatings, optical mirrors and, of course, astronomical filters.

Established in 1999 and based in Kunming City, China, Optolong/Yulong provides nearly 2000 types of optical filter coatings annually to customers worldwide in a wide variety of industries and applications. We invite you to learn more about Optolong/Yulong, their products, facilities, and processes by viewing the short video below:



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