The SVBONY SV227 OIII filter is a 2″ narrowband astrophotography filter with a 5 nm bandwidth, designed to isolate the doubly ionised oxygen (OIII) emission line at 500.7 nm. It is commonly used for imaging emission nebulae, planetary nebulae, and supernova remnants, where strong contrast and background suppression are required.

5 nm Narrowband Precision

With a narrow 5 nm passband, the SV227 OIII filter provides effective isolation of the oxygen-III emission wavelength while rejecting surrounding light pollution and sky glow. This enables higher contrast and improved signal-to-noise ratio in deep-sky imaging.

High Transmission & Deep Blocking

The filter offers peak transmission of ≥90% at the OIII wavelength, combined with deep out-of-band blocking of OD5 or greater. This helps reduce unwanted background light and supports longer exposure imaging under light-polluted skies.

Precision Optical Construction

Manufactured from high-quality optical glass, the SV227 OIII filter is designed to maintain optical flatness and parallelism, helping minimise focus shift and star distortion across the imaging field.

Standard 2″ Thread Compatibility

Featuring a standard M48 × 0.75 (2″) thread, the filter is compatible with most 2″ filter wheels, filter drawers, and imaging adapters used with astronomy cameras and telescopes.

Spectral Performance

The transmission profile is precisely centred at 500.7 nm, ensuring accurate isolation of the OIII emission line commonly used in narrowband and SHO imaging workflows.

Important Notes

• Not suitable for solar observation.
• Not recommended for optical systems faster than f/4.