Antlia 2.8nm Narrowband H-alpha Ultra Filter
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Description
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Antlia H-alpha Pro narrowband filter optimizes the FWHM (full width half maximum) to 2.8nm bandpass. As the bandwidth becomes narrower, the 2.8nm Ultra narrowband filters enhance contrast of emission targets by lowering the unwanted background signal.
The out of band blocking specification is rated OD5 (0.001%) 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 2.8nm Pro filters are designed to minimize halos around bright stars.
Application and Performance:
High transmittance and smallest bandwidth to maximize contrast
Steep spectral profile minimizes halos around bright stars
A single substrate to eliminate internal reflections
Narrowband Objects: H-alpha Emission Nebulae, Planetary, Wolf Rayet Nebulae and Supernova Remnants
Use in light polluted areas anddark sites
Extends imaging time when the moon is up
All Antlia Narrowband filters are edge blackened to eliminate internal reflections from stray light
Superior optical reliability reduces post image processing
This filter is not suited to deep sky objects that do not contain H-alpha emissions.
Technical Specifications:
Basic Substrate: Schott optical substrate
Filter Thickness: 2mm+/-0.05mm for Dia36mm
FWHM (Full width at half maximum): 2.8nm
CWL (Central Wavelength): 656.3nmnm
Peak Transmission: >88%
Blocking: > 5 OD(0.001% 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
Single / Non-glued substrate
Warranty: 3-years against delamination