Antlia 4.5nm Narrowband Sulfur II (SII) EDGE Imaging Filter - 36mm Round Unmounted
- This item is currently on backorder from the manufacturer.
- Orders are fulfilled in the order they are received once inventory arrives.
Stock count is accurate & shown in real time.
- This item is out of stock.
- Sign up for back-in-stock alerts to be notified when this item becomes available.
- This item is out of stock.
- We have no ETA from the manufacturer at this time.
- Sign up for back-in-stock alerts to be notified when this item becomes available.
Lower 48 States:
Orders over $50 ship free within the Lower 48 using a carrier and service we select based on your items and delivery location. Faster shipping options may be available at checkout.
U.S. Outside the Lower 48 (AK, HI, PR):
Free shipping on orders over $50 applies to many—but not all—items. Add items to your cart and enter your ZIP code to see available shipping options and any costs.
International Orders:
Free shipping does not apply to international orders. You’ll see available shipping options and costs during checkout. Some items can’t be shipped internationally due to size or manufacturer restrictions. Duties, taxes, brokerage fees, and tariffs are not included and are the customer’s responsibility.
IMPORTANT: Please read this important note below before buying Antlia narrowband filters. No returns will be accepted for Antlia narrowband filters exhibiting halos around bright stars as disclosed below.
Please note that some users may see halos around bright stars in images made with this filter. Such halos have been observed with filters from other leading manufacturers and in the previous generation of Antlia narrowband filters as well. These halos can be caused and/or made worse by other optical accessories in the imaging train, their relative positions, telescope design/optics, camera, software, or a combination thereof. In general, OIII filters seem to have a higher propensity to show halos compared to H-alpha or S-II filters, but in rare cases the latter filters can also exhibit faint halos around bright stars.
Antlia has made great strides in their coatings to minimize haloing of bright stars, but you may still observe this effect to some degree. See the sample OIII image below of Alnitak (magnitude 1.74) and IC434 in Orion (SkyRover 155mm Apo, ZWO 6200MM-P Camera, 20 min exposure) provided by Antlia. In most cases, haloing will not affect your image unless you have very bright stars in the field of view.
Please note we are unable to accept returns of any Antlia narrowband filters if you do observe this haloing effect in your images.
If you must ensure there are no detectable halos in your images, you may want to consider Astrodon or Chroma narrowband filters instead. These filters, however, cost two to three times as much as Antlia 3nm filters do. Antlia is being honest and upfront. They are the ones telling us about these halos, that their filters are great for the money but still not as good as Astrodon/Chroma, and pointing out that with this full disclosure, they will not accept returns. They are leaving it up to the customer to decide if this is good enough for them or not. We believe that for most imaging applications, Antlia filters continue to offer excellent value for astrophotographers and these continue to be among our top sellers.
Application and Performance:
- High transmittance and narrow bandwidth to maximize contrast
- Steep spectral profile minimizes halos around bright stars
- A single substrate to eliminate internal reflections
- Narrowband Objects: SII Emission Nebulae, Planetary, Wolf-Rayet Nebulae and Supernova Remnants
- Use in light polluted areas and dark sites
- Extend imaging time when the moon is up
- Antlia narrowband EDGE filters can be used down to f/3 systems with minimal loss of signal
- Edge blackened to eliminate internal reflections from stray light
- Superior optical reliability reduces post image processing
- This filter is only effective for deep sky objects that contain SII emissions
The Antlia SII EDGE narrowband filter optimizes the FWHM (full width half maximum) to 4.5nm bandpass. The suppression of optical density (OD) 5 on unwanted wavelengths and the excellent transmittance characteristics found in the Antlia 3nm Pro series has been incorporated into the 4.5nm EDGE narrowband filters. The result is that these filters deliver superior SNR (signal to noise ratio) and better contrast in your images.
Antlia SII 4.5nm EGDE filters are designed to deliver high transmittance at the 671.6nm line that provides you with the maximum signal to reveal the faintest SII nebulae structures, planetary nebulas and supernova remnants.
Conventional broader narrowband filters cause a heavy loss in transmission due to the strong Center Wavelength (CWL)-shift. Antlia guarantees T>90% within 1nm range of the center bandwidth for f/4.5 or slower scopes. Blue-shift data also shows that Antlia 4.5nm EDGE filters can be used with nearly all systems as fast as f/3 with minimal loss in emission signal and meets the requirements of fast optics. Hence, 4.5nm EDGE narrowband filters can guarantee high transmittance for working with both long focal ratios and fast optical systems.
When Antlia designs filters for astronomy imaging systems, they look at how they will work together with optical systems, carefully designing the out of band blocking rate, transmittance and band-pass parameters to achieve an optimum result. Each filter is individually tested and scanned by strict QC methods to ensure that the quality meets the high-performance parameters. The result is that Antlia is known for designing filters for astrophotography that achieve exceptional quality and performance parameters at affordable prices. We believe the price to performance ratio compares more favorably than similar premium filters in the market.
Technical Data:
- Schott optical substrate
- 36mm round unmounted (2mm thickness +/-0.05mm). Additional sizes available separately
- Surface Quality: 60/40 (Refer to MIL-O-13830)
- 2 sides fine-optically polished to ensure accurate 1/4 or better wavefront
- Parallelism: less than 30 arcsec
- Center-Wavelength of Antlia SII 4.5nm filter: 671.6nm
- Peak transmission > 90%
- Blocking: > 5 OD (0.001%) @ 300-1000nm
- 2 sides Multi-layers anti-reflection coating
- Single / Non-glued substrate
Filter Ring:
- None. 36mm round diameter, unmounted
Not Recommended:
- Solar Observing and imaging
- Visual observation
- DO NOT LOOK AT THE SUN WITH ANTLIA FILTERS. Serious eye damage will result if you fail to observe the warning.
Other Information
- Country of Manufacture: China
Application and Performance:
- High transmittance and narrow bandwidth to maximize contrast
- Steep spectral profile minimizes halos around bright stars
- A single substrate to eliminate internal reflections
- Narrowband Objects: SII Emission Nebulae, Planetary, Wolf-Rayet Nebulae and Supernova Remnants
- Use in light polluted areas and dark sites
- Extend imaging time when the moon is up
- Antlia narrowband EDGE filters can be used down to f/3 systems with minimal loss of signal
- Edge blackened to eliminate internal reflections from stray light
- Superior optical reliability reduces post image processing
- This filter is only effective for deep sky objects that contain SII emissions
The Antlia SII EDGE narrowband filter optimizes the FWHM (full width half maximum) to 4.5nm bandpass. The suppression of optical density (OD) 5 on unwanted wavelengths and the excellent transmittance characteristics found in the Antlia 3nm Pro series has been incorporated into the 4.5nm EDGE narrowband filters. The result is that these filters deliver superior SNR (signal to noise ratio) and better contrast in your images.
Antlia SII 4.5nm EGDE filters are designed to deliver high transmittance at the 671.6nm line that provides you with the maximum signal to reveal the faintest SII nebulae structures, planetary nebulas and supernova remnants.
Conventional broader narrowband filters cause a heavy loss in transmission due to the strong Center Wavelength (CWL)-shift. Antlia guarantees T>90% within 1nm range of the center bandwidth for f/4.5 or slower scopes. Blue-shift data also shows that Antlia 4.5nm EDGE filters can be used with nearly all systems as fast as f/3 with minimal loss in emission signal and meets the requirements of fast optics. Hence, 4.5nm EDGE narrowband filters can guarantee high transmittance for working with both long focal ratios and fast optical systems.
When Antlia designs filters for astronomy imaging systems, they look at how they will work together with optical systems, carefully designing the out of band blocking rate, transmittance and band-pass parameters to achieve an optimum result. Each filter is individually tested and scanned by strict QC methods to ensure that the quality meets the high-performance parameters. The result is that Antlia is known for designing filters for astrophotography that achieve exceptional quality and performance parameters at affordable prices. We believe the price to performance ratio compares more favorably than similar premium filters in the market.
Technical Data:
- Schott optical substrate
- 36mm round unmounted (2mm thickness +/-0.05mm). Additional sizes available separately
- Surface Quality: 60/40 (Refer to MIL-O-13830)
- 2 sides fine-optically polished to ensure accurate 1/4 or better wavefront
- Parallelism: less than 30 arcsec
- Center-Wavelength of Antlia SII 4.5nm filter: 671.6nm
- Peak transmission > 90%
- Blocking: > 5 OD (0.001%) @ 300-1000nm
- 2 sides Multi-layers anti-reflection coating
- Single / Non-glued substrate
Filter Ring:
- None. 36mm round diameter, unmounted
Not Recommended:
- Solar Observing and imaging
- Visual observation
- DO NOT LOOK AT THE SUN WITH ANTLIA FILTERS. Serious eye damage will result if you fail to observe the warning.
IMPORTANT: Please read this important note below before buying Antlia narrowband filters. No returns will be accepted for Antlia narrowband filters exhibiting halos around bright stars as disclosed below.
Please note that some users may see halos around bright stars in images made with this filter. Such halos have been observed with filters from other leading manufacturers and in the previous generation of Antlia narrowband filters as well. These halos can be caused and/or made worse by other optical accessories in the imaging train, their relative positions, telescope design/optics, camera, software, or a combination thereof. In general, OIII filters seem to have a higher propensity to show halos compared to H-alpha or S-II filters, but in rare cases the latter filters can also exhibit faint halos around bright stars.
Antlia has made great strides in their coatings to minimize haloing of bright stars, but you may still observe this effect to some degree. See the sample OIII image below of Alnitak (magnitude 1.74) and IC434 in Orion (SkyRover 155mm Apo, ZWO 6200MM-P Camera, 20 min exposure) provided by Antlia. In most cases, haloing will not affect your image unless you have very bright stars in the field of view.
Please note we are unable to accept returns of any Antlia narrowband filters if you do observe this haloing effect in your images.
If you must ensure there are no detectable halos in your images, you may want to consider Astrodon or Chroma narrowband filters instead. These filters, however, cost two to three times as much as Antlia 3nm filters do. Antlia is being honest and upfront. They are the ones telling us about these halos, that their filters are great for the money but still not as good as Astrodon/Chroma, and pointing out that with this full disclosure, they will not accept returns. They are leaving it up to the customer to decide if this is good enough for them or not. We believe that for most imaging applications, Antlia filters continue to offer excellent value for astrophotographers and these continue to be among our top sellers.
Application and Performance:
- High transmittance and narrow bandwidth to maximize contrast
- Steep spectral profile minimizes halos around bright stars
- A single substrate to eliminate internal reflections
- Narrowband Objects: SII Emission Nebulae, Planetary, Wolf-Rayet Nebulae and Supernova Remnants
- Use in light polluted areas and dark sites
- Extend imaging time when the moon is up
- Antlia narrowband EDGE filters can be used down to f/3 systems with minimal loss of signal
- Edge blackened to eliminate internal reflections from stray light
- Superior optical reliability reduces post image processing
- This filter is only effective for deep sky objects that contain SII emissions
The Antlia SII EDGE narrowband filter optimizes the FWHM (full width half maximum) to 4.5nm bandpass. The suppression of optical density (OD) 5 on unwanted wavelengths and the excellent transmittance characteristics found in the Antlia 3nm Pro series has been incorporated into the 4.5nm EDGE narrowband filters. The result is that these filters deliver superior SNR (signal to noise ratio) and better contrast in your images.
Antlia SII 4.5nm EGDE filters are designed to deliver high transmittance at the 671.6nm line that provides you with the maximum signal to reveal the faintest SII nebulae structures, planetary nebulas and supernova remnants.
Conventional broader narrowband filters cause a heavy loss in transmission due to the strong Center Wavelength (CWL)-shift. Antlia guarantees T>90% within 1nm range of the center bandwidth for f/4.5 or slower scopes. Blue-shift data also shows that Antlia 4.5nm EDGE filters can be used with nearly all systems as fast as f/3 with minimal loss in emission signal and meets the requirements of fast optics. Hence, 4.5nm EDGE narrowband filters can guarantee high transmittance for working with both long focal ratios and fast optical systems.
When Antlia designs filters for astronomy imaging systems, they look at how they will work together with optical systems, carefully designing the out of band blocking rate, transmittance and band-pass parameters to achieve an optimum result. Each filter is individually tested and scanned by strict QC methods to ensure that the quality meets the high-performance parameters. The result is that Antlia is known for designing filters for astrophotography that achieve exceptional quality and performance parameters at affordable prices. We believe the price to performance ratio compares more favorably than similar premium filters in the market.
Technical Data:
- Schott optical substrate
- 36mm round unmounted (2mm thickness +/-0.05mm). Additional sizes available separately
- Surface Quality: 60/40 (Refer to MIL-O-13830)
- 2 sides fine-optically polished to ensure accurate 1/4 or better wavefront
- Parallelism: less than 30 arcsec
- Center-Wavelength of Antlia SII 4.5nm filter: 671.6nm
- Peak transmission > 90%
- Blocking: > 5 OD (0.001%) @ 300-1000nm
- 2 sides Multi-layers anti-reflection coating
- Single / Non-glued substrate
Filter Ring:
- None. 36mm round diameter, unmounted
Not Recommended:
- Solar Observing and imaging
- Visual observation
- DO NOT LOOK AT THE SUN WITH ANTLIA FILTERS. Serious eye damage will result if you fail to observe the warning.
Other Information
- Country of Manufacture: China
| Free Shipping Graphic | Free US Shipping |
|---|---|
| Hide Found a better Shipped Price on Frontend? | No |
Antlia 4.5nm Narrowband Sulfur II (SII) EDGE Imaging Filter - 36mm Round Unmounted