Antlia SHO Narrowband 3nm Pro Imaging Filter Set - 36mm Unmounted

Description

Antlia SHO Narrowband 3nm 36mm Pro Highspeed Filter Set

For Fast Telescopes (f/2.6 to f/3.6)

The Antlia SHO 3nm Pro Highspeed filter set is designed for serious astrophotographers using fast optical systems. Optimized for focal ratios between f/2.6 and f/3.6, these filters deliver exceptional contrast, signal-to-noise ratio (SNR), and detail—even under challenging light conditions or when imaging faint nebulae.

Why Highspeed Filters?

Fast telescopes create a wider light cone, which causes the central wavelength of interference filters to shift toward the blue end of the spectrum. Antlia addresses this issue by pre-shifting each filter’s wavelength slightly toward the red. This ensures that even with a blue shift of about 2.2nm (as seen at f/2.6), your telescope still captures the maximum signal in the target emission lines.

Improved Imaging for Emission Nebulae

Compared to standard 3nm filters, the Highspeed versions offer noticeably stronger contrast and sharper detail when used with fast optics. If your system is slower than f/3.6, the standard 3nm Pro filters are more suitable. For optics faster than f/2.6, consider Antlia’s 4.5nm EDGE filters.

Key Features

• True 3nm bandwidth for H-alpha (Ha), OIII, and SII lines
• Pre-shifted CWL to correct for blue shift in fast optical systems
• >90% peak transmission for excellent signal capture
• Optimized for f/2.6 – f/3.6 focal ratios
• OD5 (≥99.999%) out-of-band blocking to reduce background noise
• Minimal halos around bright stars
• Single, non-glued optical substrate – eliminates internal reflections
• Edge-blackened filters for stray light suppression
• Excellent mechanical and optical quality
  • Surface quality: 60/40 (MIL-O-13830)
  • Transmitted wavefront: λ/4 or better
  • Parallelism: <30 arcsec

Suitable For

• Emission nebulae (H-alpha, OIII, SII)
• Planetary nebulae
• Wolf-Rayet nebulae
• Supernova remnants
• Imaging from light-polluted areas or under moonlight

Technical Specifications

Construction & Quality

• Material: Optical-quality, single-substrate (non-glued)
• Edge treatment: Fully blackened to eliminate stray reflections
• Surface Finish: Black anodized, laser-engraved (won’t fade)
• Filter Cell: Ultra-thin design to reduce vignetting

Not Suitable For

• Solar imaging
• Nighttime visual observation

Warning: Never use this filter to observe the Sun directly. Doing so will result in serious eye damage.

Warranty

• 3-year warranty against delamination and manufacturing defects
• Designed for long-term durability and consistent performance