Antlia ALP-T Dual Band 3 nm Ha/OIII Highspeed Filter 2" (Antlia) is a dual-band narrowband filter designed for emission nebula astrophotography with fast optical systems. It enables the simultaneous capture of hydrogen Hα and oxygen OIII emission lines, while the pre-shifted transmission bands reduce signal loss caused by blueshift in telescopes with low focal ratios. The filter is designed primarily for use with OSC colour astronomy cameras.

Key features

• two narrow transmission bands with a nominal FWHM of 3 nm for the Hα and OIII lines
• simultaneous capture of hydrogen Hα and oxygen OIII signals with an OSC colour camera
• Highspeed version with pre-shifted transmission bands, designed for fast optical systems
• compensation for the shift towards shorter wavelengths occurring at large angles of incidence
• strong suppression of unwanted radiation from artificial lighting, moonlight and atmospheric airglow
• improved emission nebula contrast and signal-to-noise ratio of the captured data
• suitable for use with monochrome cameras as a dual-band luminance filter
• multi-layer coatings applied to both sides using Ion Gun Assisted Deposition technology
• anti-reflection coatings reducing halos and internal reflections
• slim 2" cell reducing the risk of vignetting

Set contents

• Antlia ALP-T Dual Band 3 nm Ha/OIII Highspeed Filter 2"

Technical specifications

• filter type: dual-band narrowband astrophotography filter
• version: Highspeed with pre-shifted transmission bands
• transmitted emission lines: Hα and OIII
• nominal Hα line wavelength: 656.3 nm
• nominal OIII line wavelength: 500.7 nm
• nominal Hα FWHM bandwidth: 3 nm
• nominal OIII FWHM bandwidth: 3 nm
• primary compatibility: OSC colour astronomy cameras
• additional compatibility: monochrome cameras
• optical application: fast astrophotography systems
• application: emission nebula imaging
• cell size: 2"
• cell thread: M48 × 0.75
• cell finish: black anodising and durable laser markings
• suitable for visual observation: no
• suitable for solar imaging: no

The Antlia ALP-T Dual Band 3 nm Ha/OIII Highspeed Filter allows a colour camera to capture two primary emission bands simultaneously while maintaining effective signal transmission in fast astrophotography setups.