Antlia 2.8nm Narrowband Sulfur II (SII) Ultra Imaging Filter - 36mm Round Unmounted
Availability: Item has been discontinued by the manufacturer
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The Antlia SII 2.8nm Ultra filter uses OHARA quartz glass and is manufactured under precisely controlled coating processes. The Ultra series are optimized with a FWHM (full width half maximum) of 2.8nm+/-0.5nm and a transmission efficiency >97% at the emission wavelength. The result is a very high Signal to Noise Ratio.
The OHARA quartz glass has an ultra-low thermal expansion coefficient with outstanding thermal and mechanical properties. When these superior glass characteristics are combined with advanced coating processes, these filters will provide excellent durability for imaging and research in the toughest environmental conditions.
All the 2.8nm Ultra filters are 100% scanned individually, all transmission and blocking (OD) data in the box are actual, measured spectra.
Compared with 3nm Pro series, 2.8nm Ultra series coated on OHARA quartz glass and showed higher transmittance SII＞97%. It is estimated that these filters will provide 20-30% signal improvement in your images as compared to the 3nm Pro series. In addition, the Ultra series has a 10% narrower FWHM 2.8nm+/-0.5nm. The Ultra series narrowband filters will allow you to capture improved contrast and structural detail.
Features:
- High transmittance（SII＞97%）and the narrowest FWHM 2.8nm+/-0.5nm to maximize contrast
- Flat-top spectrum minimizes the loss in transmission due to the Center Wavelength (CWL)-shift
- Out of band blocking specification is designed to OD5 (0.001%) to block interference from other wavelengths and minimize halos around bright stars
- Made of OHARA quartz glass, excellent durability and thermal stability, better fracture resistance and scratch resistance, improved coating resilience to cleaning
- Identical filter thickness to existing standards and double-sided fine polishing , with utmost care for parfocality
- SII 2.8nm Ultra filters can be used down to f/3.5 systems with minimal loss of signal. (This does not mean that optics with faster focal ratios will not be applicable, the flat-top design reduce the effect of wavelength shift and you can still use the 2.8nm Ultra narrowband)
- 100% of production are scanned individually, all transmission and blocking (OD) data in the box are actual, measured spectra and transmission
- All Antlia filters are coated to the edge of the substrate and unmounted narrowband filters are edge blackened to eliminate internal reflections from stray light
- Warranty: 3-years against delamination
Technical Specifications:
Sulfur-II
- FWHM: 2.8nm+/-0.5nm
- CWL (Central Wavelength): 672.4nm
- Peak Transmission: 97%
- Blocking: ≥OD5
- Filter Thickness: 2mm+/-0.05mm
Filter Ring:
- None. 36mm round unmounted
Not Recommended:
- Solar imaging
- Night visual observation
- DO NOT LOOK AT THE SUN WITH ANTLIA FILTERS. Serious eye damage will result if you fail to observe the warning.
| Product Banner Type | discontinued |
|---|---|
| Free Shipping Graphic | Free US Shipping |
| Hide Found a better Shipped Price on Frontend? | No |
The Antlia SII 2.8nm Ultra filter uses OHARA quartz glass and is manufactured under precisely controlled coating processes. The Ultra series are optimized with a FWHM (full width half maximum) of 2.8nm+/-0.5nm and a transmission efficiency >97% at the emission wavelength. The result is a very high Signal to Noise Ratio.
The OHARA quartz glass has an ultra-low thermal expansion coefficient with outstanding thermal and mechanical properties. When these superior glass characteristics are combined with advanced coating processes, these filters will provide excellent durability for imaging and research in the toughest environmental conditions.
All the 2.8nm Ultra filters are 100% scanned individually, all transmission and blocking (OD) data in the box are actual, measured spectra.
Compared with 3nm Pro series, 2.8nm Ultra series coated on OHARA quartz glass and showed higher transmittance SII＞97%. It is estimated that these filters will provide 20-30% signal improvement in your images as compared to the 3nm Pro series. In addition, the Ultra series has a 10% narrower FWHM 2.8nm+/-0.5nm. The Ultra series narrowband filters will allow you to capture improved contrast and structural detail.
Features:
- High transmittance（SII＞97%）and the narrowest FWHM 2.8nm+/-0.5nm to maximize contrast
- Flat-top spectrum minimizes the loss in transmission due to the Center Wavelength (CWL)-shift
- Out of band blocking specification is designed to OD5 (0.001%) to block interference from other wavelengths and minimize halos around bright stars
- Made of OHARA quartz glass, excellent durability and thermal stability, better fracture resistance and scratch resistance, improved coating resilience to cleaning
- Identical filter thickness to existing standards and double-sided fine polishing , with utmost care for parfocality
- SII 2.8nm Ultra filters can be used down to f/3.5 systems with minimal loss of signal. (This does not mean that optics with faster focal ratios will not be applicable, the flat-top design reduce the effect of wavelength shift and you can still use the 2.8nm Ultra narrowband)
- 100% of production are scanned individually, all transmission and blocking (OD) data in the box are actual, measured spectra and transmission
- All Antlia filters are coated to the edge of the substrate and unmounted narrowband filters are edge blackened to eliminate internal reflections from stray light
- Warranty: 3-years against delamination
Technical Specifications:
Sulfur-II
- FWHM: 2.8nm+/-0.5nm
- CWL (Central Wavelength): 672.4nm
- Peak Transmission: 97%
- Blocking: ≥OD5
- Filter Thickness: 2mm+/-0.05mm
Filter Ring:
- None. 36mm round unmounted
Not Recommended:
- Solar imaging
- Night visual observation
- DO NOT LOOK AT THE SUN WITH ANTLIA FILTERS. Serious eye damage will result if you fail to observe the warning.
| Product Banner Type | discontinued |
|---|---|
| Free Shipping Graphic | Free US Shipping |
| Hide Found a better Shipped Price on Frontend? | No |