Touptek SHO 6.5nm Filters for Astrophotography

Touptek SHO 6.5nm Filters for Astrophotography

Narrowband filters are essential accessories in astrophotography used to isolate specific wavelength emission lines and enhance the signal-to-noise ratio of your target—especially for capturing breathtaking emission nebulae.

ToupTek HSO narrowband filters are precisely tuned to the three main ionized emission lines found in star-forming regions:

• Hα (656.3nm)
• SII (671.6nm)
• OIII (500.7nm)

Precise Band Control & Enhanced Detail Resolution

The precise narrowband design effectively suppresses background noise while highlighting the emission structures of different elements, resulting in clearer celestial stratification and enhanced detail gradation.

• Hα filter: Central wavelength 656.3nm, FWHM 4nm. Optimized for hydrogen ionization regions, this filter serves as the primary channel for capturing nebular morphology.
• OIII filter: Central wavelength 500.7nm (OIII emission line), FWHM 4nm. Designed to reveal high-energy excitation zones, particularly effective for visualizing blue-green nebular details.
• SII filter: Central wavelength 671.6nm, FWHM 4nm. Enhances detection of faint signals and reveals structural stratification through ionized sulfur distribution. When combined with Hα, significantly improves image contrast.

High-Quality Quartz Glass, High Transparency and Purity

The entire series of ToupTek Astro filters utilize high-quality colorless transparent quartz glass, with >90% high transmittance, high purity, exceptional blue-violet band transmission, and outstanding thermal stability—ideal for various demanding astronomical imaging applications.

IAD Dense Coating, Durable and Stable

Using IAD (Ion Assisted Deposition) coating technology, which is more costly than conventional vacuum evaporation but produces denser and more uniform coatings that are durable, corrosion-resistant, and have superior environmental stability.

Precision Coating, Significantly Suppresses Halos

ToupTek Astro filters employ a proprietary multi-layer system: a single-sided cutoff coating, front surface AR anti-reflection coating, and edge blackening treatment. This combination effectively minimizes internal reflections and stray light while ensuring coating integrity and extended service life.

High Optical Cutoff Depth, Restores Natural Colors

All channel filters have a cutoff depth of OD≥5.0, effectively blocking non-target spectral regions, avoiding band crosstalk and color cast, resulting in accurate and natural color reproduction.

Matte Black Edge Coating, Easy Installation

The filter edge is coated with a black matte treatment to minimize stray light, which ensures transmittance, reduces glare, and enhances image contrast.

• 1.25" & 2" filters: Feature threaded aluminum alloy frames for direct screw-in installation, ensuring fast and tool-free mounting.

Highly Compatible

All filters use a single-piece, glue-free structure.

• 36mm: Recommended for APS-C and smaller cameras.
• 1.25": Recommended for cameras with a 1-inch or smaller sensor.
• 2": Recommended for full-frame and smaller cameras.

Compatible with various brands on the market featuring 7-hole 36mm, 8-hole 1.25-inch, and 5-hole 2-inch electric filter wheels, offering a wider range of compatibility options.

Spectrum

Technical Specifications

In the box

• 1.25''
• 2''