Dual-Band 7nm H-alpha and OIII Filter for OSC Cameras

Pull sharp nebula detail out of a light-polluted sky.

This dual-band 7nm H-alpha and OIII filter is built for one-shot color (OSC) CMOS and CCD cameras. Its narrow 7nm bandpass centers on Hydrogen-alpha (H-a) and Oxygen III (OIII), passing the wavelengths that matter most for emission and planetary nebulae while blocking most artificial and natural skyglow. That lets you shoot long-exposure deep-sky images from a balcony or backyard.

Why we picked it

• Dual 7nm narrowband - Isolates H-alpha and OIII for strong contrast on emission nebulae, planetary nebulae, and supernova remnants.
• Made for OSC cameras - Captures full-color data in one session, so acquisition and processing stay simpler.
• Tames skyglow - Holds back most urban light and moonlight for imaging from bright locations.

Good to know

It is designed for telescopes at f/5 and slower. By passing only the H-a (red) and OIII (green-blue) lines, it lifts faint structure and reduces the pull of moonlight and street lighting. It comes in 1.25" and 2" sizes, with M48 x 0.75 threading on the 2" version, and ships in a PP plastic storage box.

Common questions

Q: Can I use it with a monochrome camera?
A: It is tuned for one-shot color cameras but works with monochrome sensors too.

Q: Does it help under a bright Moon?
A: Yes. The 7nm bandpass cuts the effect of moonlight, so it stays useful during bright lunar phases.

Q: Which targets suit it best?
A: Emission nebulae, planetary nebulae, and supernova remnants with strong H-a and OIII lines.

Q: Will it skew color balance?
A: It passes the H-a and OIII lines while keeping color channels consistent, so nebulae look natural after standard processing.