ZWO SII 7 nm Filter - 36mm - SII36
Optolong SII 6.5nm Filter - EOS Full Frame Clip - EOSFF-SII65 is no longer available.
We recommend these products instead:
ZWO 36mm Narrowband Filter Set with OIII, SII, & Ha Filters - NBSET-36
ZWO 31mm Narrowband Filter Set with OIII, SII, & Ha Filters - NBSET-31
ZWO 1.25" Narrowband Filter Set with OIII, SII, & Ha Filters - NBSET-125
Optolong SII 6.5nm CCD Clip Filter for Canon EOS Full Frame Cameras
Optolong's Sulfur II is an Extra-Narrowband Filter, allowing only a 6.5nm bandwidth of light, centered at 672nm to pass through. This filter reduces other transmissions as well, including wavelengths of light responsible for light pollution (both artificial and natural). Like all Optolong filters with the“CCD” designation, this SII filter also blocks infrared wavelengths from 700nm to 1100nm so you don't need a separate IR-Cut filter.
The Optolong 6.5nm SII filter can be used in conjunction with H-Alpha and OIII filters for false color emission line images like the Hubble Space Telescope.
The Optolong SII 6.5nm EOS Full Frame Clip Filter is made with Schott glass that has been multi-coated with an ion-assisted deposition technology to ensure scratch resistance and stability on the central wavelength, or CWL. The filter cell is made of lightweight, strong metal and is CNC machined, sand-blasted, black anodized, and then laser engraved.
Using a Clip Filter on your Canon Full Frame Camera
- The Optolong EOS FF Clip filter can be inserted without tools; just use your fingers to insert or remove the filter. Once inserted correctly, it cannot unintentionally fall out.
- No changes to the housing of Canon EOS DSLR are required. All lens functions will work with the Clip installed, including focus, screen, and image stabilization,
- The Optolong clip filter prevents dust from settling on the sensor during long exposures.
- The EOS FF clip filters are compatible with EOS Full Frame series cameras, such as the 1D X, 5D, and 6D. If you have a standard APS-C EOS camera, Optolong offers clip filters for these cameras as well.
- Optolong Clip Filters do not function with the Canon EF-S series lenses. These lenses invade the space inside the camera body that would normally be taken up by the clip filter.
- To use EOS/T2 and 2” adapters to attach your camera to a telescope you’ll need to insert the Clip-Filter first and then install the desired lens adapters.
Quality Filter Materials:
- Schott B260 substrate material from Germany, 1.0mm thick
- CNC machined and black anodized aero-metal filter cell that is ultra-thin to provide largest clear aperture; Laser-engraved to prevent fading
- Multiple layers of anti-reflection non-cementing coatings applied via electron-beam gun evaporation with Ion-assisted deposition
Optolong Filter Manufacturing Processes and Parameters
- Filter substrate is fine-optically polished to 1/4 wave and <30 parallelism over both surfaces
- Surface quality, according to MIL-O-13830, is 60/40
- 80% transmission at SII line 672nm
- Infrared wavelength 700-1100nm cut-off
- 0.1% transmission Hg at 435nm and 578nm
- 0.1% transmission Na at 589nm
- High-value transmission of pass-band and optical density of off-band is assured through Optolong’s planetary rotation system, a homogeneous and precise coating procedure
- Each filter comes with a plastic case with high-pressure EVA case lining
Optolong is the Astronomy Filters division of Yulong Optics, an optical filter design, and processing company out of Kunming, China that has provided filters for over 700 optical companies since 1999. All Optolong filters pass European Union RoHS requirements and have been certified by TUV Rheinland and Bureau Veritas.
Optolong SII 6.5nm Filter in Canon EOS Full Frame Clip Format
- Filter Case
Dimensions & Specifications
Filter Size: EOS Full Frame Clip
Filter Type: Narrowband Imaging
Filter Shape:EOS Clip
Mounted or Unmounted: Mounted
We stand behind all the products we sell, and your satisfaction is our top priority. If you're not satisfied with the quality of your purchase, simply send the item back to us in its original packaging within 30 days of its delivery.
Return & Exchange Policy
At our site, returns are easy! You may return new, unused, and resalable items for a refund or exchange. Simply ensure that the item is returned in its original product packaging within 30 days of delivery.
Most Helpful Reviews
Most Critical Reviews
Displaying Reviews 1-10 of