Antlia SII Prime narrowband filter optimizes the FWHM (full width half maximum) to 7nm bandpass. The suppression of optical density is (OD)4 on unwanted wavelengths. The excellent optical coating characteristics found in the Antlia 3nm Pro series has been incorporated into the 7nm Prime narrowband filters. The result is that these filters deliver superior SNR(signal to noise ratio) and better contrast in your images.
Antlia SII 7nm Prime filters are designed to achieve 90% transmittance at the central wavelength (CWL) of 672.4nm. Furthermore, these filters highly transmit the SII emission lines at 671.6nm and 673.1nm, ensuring maximum signal strength and well-defined nebular structures.
The out of band blocking specification is rated OD4 (0.01%) which delivers an excellent SNR(signal to noise ratio) and effective cut off rate to minimize interference from other wavelengths. Improved sharp cut off astrophotography 7nm Prime filters are designed to minimize halos around bright stars.
Antlia 7nm Prime filters can be used with nearly all systems as fast as f/2 with minimal loss in emission signal and meets the requirements of fast optics.
Application and Performance:
90% transmittance at Central Wavelength 672.4nm
High transmittance to pass SII emission lines at the 671.6nm and 673.1nm
With wider FWHM, 7nm Prime narrowband filters can be used with fast optics of f/2 with minimal loss of signal
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
All Antlia Narrowband filters are edge blackened to eliminate internal reflections from stray light
Superior optical reliability reduces post image processing
This filter is ffective for deep sky objects that contain SII emissions
Technical Specifications:
Basic Substrate: Optical, Single / Non-glued substrate
Filter Thickness: 2mm+/-0.05mm for Dia36mm unmounted
FWHM (Full width at half maximum): 7nm
CWL (Central Wavelength): 672.4nm
Peak Transmission: ＞90%
Blocking: > 4OD(0.01% out of band blocking) @ 300-1000nm
Surface Quality: S/D (scratch/dig)= 60/40 (Refer to MIL-O-13830)
Transmitted Wavefront: Lambda/4 or better.
Parallelism: less than 30 arcsec
Warranty: 3-years against delamination
Spectrum Curve:
Available Sizes：
Unmounted Dia36mm
Not Recommended:
Solar imaging
Night visual observation
Not Permitted:
DO NOT LOOK AT THE SUN WITH THIS FILTER
Serious eye damage will result if you fail to observe the warning
