Antlia H-alpha 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 H-alpha 7nm Prime filters are designed to deliver 90% transmittance at the CWLHa 656.3nm lines that provides you with the maximum signal and well-defined nebulae structures. Besides, it is wide enough (7nm bandwidth) to pass emission lines at NII 654.8nm and NII 658.3nm. 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 H-alpha 656.3nm line
FWHM is wide enough to pass both H-alpha and NII lines
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: H-alpha,NII Emission Nebulae, Planetary, Wolf Rayet Nebulae and Supernova Remnants
Use in light polluted areas and dark sites
All Antlia unmounted filters are edge blackened to eliminate internal reflections from stray light
Superior optical reliability reduces post image processing
This filter is effective for deep sky objects that contain H-alpha and NII 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): 656.3nm
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
When we design filters for astronomy imaging systems, we 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 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.