Antlia PRO H-Alpha (Ha) 3.0 nm Ultra-Narrowband Filter – 31 mm Unmounted
Just arrived! The new Antlia PRO 3.0 nm series delivers even better performance than previous 3.5 nm models.
The Antlia H-Alpha (Ha) 3.0 nm filter is designed for capturing fine detail in nebulae, planetary nebulae, and supernova remnants. With a precise 3.0 nm bandwidth centred on 656.3 nm, it provides high transmission of H-Alpha emissions while strongly rejecting unwanted light from artificial sources such as mercury and sodium lamps.
Its ultra-narrow design allows deep-sky imaging even under heavy light pollution, producing strong contrast and exceptionally dark backgrounds. At darker sites, the filter brings out the faintest nebular structures with outstanding clarity.
Optical Performance
- Ultra-narrow 3.0 nm bandwidth centred at 656.3 nm.
- Typical transmission of 90 % for the H-Alpha signal.
- Excellent out-of-band blocking rated at OD3 (0.1 %) to maximise signal-to-noise ratio.
- Sharp cut-off design minimises halos and delivers high contrast with deep black backgrounds.
- Each filter individually tested and scanned to meet Antlia’s strict optical standards.
- Substrate thickness tolerance within ±0.05 mm for precise optical alignment.
Applications
- Ideal for imaging H-Alpha emission nebulae, planetary nebulae, and supernova remnants.
- Works perfectly with Ha, S II, O III filters for full narrowband or Hubble-palette imaging.
- Excellent results with Ha + O III Bi-Color combinations.
- Suitable for use in both light-polluted and dark-sky environments.
- All Antlia narrowband filters are edge-blackened to prevent stray-light reflections.
- Can be combined with broadband LRGB data to enhance H-Alpha regions in galaxies.
Note: This filter is intended for targets that emit in the H-Alpha wavelength and is not suitable for broadband deep-sky imaging of objects without Ha emissions.
Technical Data:
- Schott optical substrate
- 1.25”, 2” mounted, 31mm,36mm dia (2mm+/-0.05mm)
- 50mm dia，50*50mm，65*65mm square (3mm+/-0.05mm)
- Surface Quality: 60/40 (Refer to MIL-O-13830)
- 2 sides fine-optically polished to ensure accurate 1/4 wavefront
- 30 arcsec parallelism
- Center-Wavelength of Antlia H-Alpha 3.0nm filter: 656.3nm
- H-Alpha 656.3nm T＞90%, 90 % transmission at H-Alpha line at 656.3nm
- min OD5（0.001%）@ 300-1000nm
- Both sides with multi-layer anti-reflection coating
- Single / Non-glued substrate
Filter Cell (specifications for cell mounted filters only):
- 1.25” (M26*0.6)，2” (M48*0.75)
- Ultra-thin filter cell to minimize vignetting by maximize possible clear aperture
- Black Anodized Finish
- Non-Fading Laser Engraving
Available Sizes：
- Mounted： 1.25” & 2” (2mm thickness)
- Unmounted：Dia 31mm，Dia 36mm (2mm thickness)
- Unmounted：Dia 50mm (3mm thickness)
- Unmounted：50*50mm，65*65 square (3mm thickness)
Not Recommended:
- Solar Observing and imaging
- Visual observation
-
IMPORTANT! DO NOT LOOK AT THE SUN WITH ANTLIA FILTERS.
Serious eye damage will result if you fail to observe the warning.
-
IMPORTANT! DO NOT LOOK AT THE SUN WITH ANTLIA FILTERS.
USER CONTRIBUTION:
MELOTTE 15 – “THE HEART OF THE HEART NEBULA” (IMAGE FURTHER BELOW...)
- Subject: Melotte 15 – “The Heart of the Heart Nebula”
- Imaging OTA: Sharpstar SCA260 – 1300mm, f/5.0
- Imaging Camera: ZWO ASI2600MM-PRO
- Filters:
Antlia 2” Narrowband: Ha (3nm); Sii (3.5nm); Oiii (3.5nm) - Filter Wheel: ZWO 7 x 2”
- Guide System: ZWO OAG-L with ZWO ASI174MM camera
- Mount:
Skywatcher EQ6-R - Capture Details: Ha: 30 x 300s; Sii: 26 x 300s; Oiii: 26 x 300s
- Integration time: 6h40’
- Bortle 4 over 4 nights
Courtesy of Alistair Scobie
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