① Shoot — Frame the Right Star
Position a bright star (magnitude ~1 or brighter) in the center of your frame.
This helps the filter properly isolate and enhance the target star for the best optical effect.
② Set — Dial in Your Camera Settings
For optimal performance, always prioritize light intake:
- Use the widest aperture your lens allows
- For wide-angle lenses, shoot at maximum aperture
- Avoid stopping down unless needed for specific sharpness control
Recommended Aperture by Focal Length
10–11mm → F 1.2–2.5
12mm → F 1.2–2.8
14mm → F 1.2–3.5
16mm → F 1.2–4.0
18mm → F 1.2–4.5
20mm → F 1.2–5.0
24mm → F 1.2–5.6
28–600mm+ → F 1.2–5.6 or slower
💡 Note: These aperture recommendations are only for focusing with a Bahtinov diffraction pattern.
They are not your final shooting settings — remove the filter after focusing and shoot as normal.
③ Care — Protect Your Filter
To maintain long-term optical quality:
- Store in a protective filter case after use
- Keep away from high-temperature environments
- Clean gently if needed:
Start with an air blower
Use neutral lens cleaning solution for oil or residue - Handle with care — the filter surface is not scratch-resistant