New ALP-T Dual Band (Ha-OIII) 3nm FILTER from Antlia 2"
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    • New ALP-T Dual Band (Ha-OIII) 3nm FILTER from Antlia 2"
    • New ALP-T Dual Band (Ha-OIII) 3nm FILTER from Antlia 2"
    • New ALP-T Dual Band (Ha-OIII) 3nm FILTER from Antlia 2"

    Antlia ALP-T Dualband 3nm Ha and OIII Filter - 2" Mounted

    379.00
    Tax included

    Antlia ALP-T Dualband 3nm Ha and OIII Filter - 2" Mounted

    Antlia ALP-T narrowband dual filter, 3nm bandwidth, 2" mounted, designed to isolate H-alpha and OIII lines. Perfect for imaging nebulae in light-polluted environments.

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    Antlia ALP-T Dualband 3nm Ha and OIII Filter - 2" Mounted

    Description:
    The Antlia ALP-T Dualband 3nm Filter (2" mounted) is a narrow dual-band filter transmitting only the H-alpha (656.3nm) and OIII (500.7nm) emission lines. Designed primarily for one-shot color cameras (OSC), it can also be used as a luminance filter with monochrome sensors to reduce imaging time.

    Its ultra-narrow 3nm bandwidth and high optical density (OD4.5) allow efficient blocking of light pollution, moonlight, and skyglow, resulting in high-contrast nebula imaging.

    Recommended for optics slower than f/4. For faster systems, a pre-shifted highspeed version is available. Antlia uses double-sided ion-assisted coating on polished substrates for uniformity and precision.

    Technical specifications:

    • FWHM: 3nm (+0.6 / -0.1nm) for Ha and OIII

    • Central wavelengths: 656.3nm (Ha), 500.7nm (OIII)

    • Peak transmission: 90% (Ha), 82% (OIII)

    • Blocking range: ≥ OD4.5 between 300 and 1100nm

    • Thickness: 2mm ± 0.05mm

    • Substrate: Optical, single-sided, non-glued

    • Surface quality: 60/40 (MIL-O-13830)

    • Wavefront flatness: Lambda/4 or better

    • Parallelism: < 30 arcsec

    • Thread: 2" (M48x0.75)

    Additional information:

    • Designed for OSC but also works with mono sensors

    • AR coating to suppress halos and internal reflections

    • Ultra-thin cell to reduce vignetting

    • Permanent laser engraving

    • Recommended with Antlia SII&Hb filter to create 4-channel narrowband images (Ha, OIII, SII, Hb)

    • Not for solar imaging or nighttime visual use

    • Do not observe the Sun with this filter

    Technical Specifications

    Hydrogen-alpha

    Oxygen III

    FWHM

    3nm +0.6/-0.1nm

    3nm +0.6/-0.1nm

    CWL (Central Wavelength)

    656.3nm

    500.7nm

    Peak Transmission

    90%

    82%

    Blocking

    OD4.5 @ 300-1100nm

    Filter Thickness

    2mm+/-0.05mm

    Basic Substrate

    Optical, Single / Non-glued substrate

    Surface Quality

    S/D (scratch/dig)= 60/40 (Refer to MIL-O-13830

    Transmitted Wavefront

    Lambda/4 or better.

    Parallelism

    less than 30 arcsec

    Filter Ring

    2'' (M48*0.75)

    Spectrum Curve:

    2025 ALP-T dualband 3nm Ha&OIII spectrum.jpg

    Antlia ALP-T Ha-OIII_3 Filter 2"
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