Antlia ALP-T Dual Band 5nm Ha&OIII filter
Capture H-alpha and OIII nebulae simultaneously with the Antlia ALP-T Dual Band 5nm filter. Ideal for color cameras (OSC) and equally effective for monochrome sensors, this filter maximizes contrast while drastically reducing light pollution.
Key features
- Double band Simultaneous transmission of H-alpha (656.3nm) and OIII (500.7nm) lines.
- Ultra-tight FWHM of 5nm for each band, increasing contrast.
- Delete OD4.5 undesirable wavelengths (light pollution, sky glow, moonlight).
- OSC and monochrome compatibleperfect for DSLR, CMOS and CCD cameras.
- Ion Gun Assisted Deposition coating technology for maximum spectrum and transmission stability.
- Near infrared (NIR) rejection up to 1100nm for optimum image quality.
Ideal applications
- Astrophotography of emission nebulae (H-alpha and OIII)
- Working in light-polluted environments (Bortle 5 to Bortle 8)
- Photographic sessions under the presence of the Moon
- Use with high-speed optics without significant signal degradation
Technical specifications
| Parameter |
Hydrogen-alpha |
Oxygen III |
| FWHM |
5nm |
5nm |
| Center wavelength (CWL) |
656.3nm |
500.7nm |
| Maximum transmission |
92% |
88% |
| Out-of-band blocking |
≥OD4.5 from 300 to 1100nm |
| Filter thickness |
2mm ± 0.05mm |
Available formats and indicative prices
- Mounted 2" (M48x0.75): USD 380
- Unmounted Ø36mm (B-4836 adapter included): USD 298
- Other sizes: availability to be confirmed
Filter design
- Ultra-thin cell to reduce vignetting
- Black anodized finish
- Weather-resistant laser engraving
Field-proven performance
The Antlia ALP-T 5nm filter has been tested on a number of well-known deep-sky targets:
- IC434 (Horsehead Nebula) - 24 exposures of 300s each
- NGC2244 (Rosette Nebula) - 30 exposures of 300s each
- NGC6960 (Western Veil Nebula) - 7 exposures of 300s each
- IC63 (Cassiopeia Phantom) - 32 exposures of 300s each
- Betelgeuse and Aldebaran (magnitude tests)
All images taken under a Bortle 5 sky with a Skywatcher 130mm f/5 + MPCC corrector, Losmandy G11 mount, IMX571 camera.
Safety warning
Never use this filter to observe the Sun. This could cause serious eye damage.
