Balancing motion clarity and low-light brightness hinges on choosing a shutter speed that aligns with your fixed output framerate. Use the 180° shutter rule—shutter ≈ 1 / (2 × frame rate)—as a starting point.
Where to configure shutter speed
- OSD menu: MENU ▶ CAMERA ▶ EXPOSURE ▶ Shutter
- Web GUI: VIDEO tab ▶ Camera Settings ▶ Exposure ▶ Shutter Speed
Frame Duration & 180° Rule Shutter Speeds
| Frame Rate | Frame Duration | 180° Rule Shutter | Valid Shutter Range |
|---|---|---|---|
| 60 fps | 16.67 ms | 1/120 s | 1/60 s – 1/10000 s |
| 50 fps | 20.00 ms | 1/100 s | 1/50 s – 1/10000 s |
| 30 fps | 33.33 ms | 1/60 s | 1/30 s – 1/10000 s |
| 25 fps | 40.00 ms | 1/50 s | 1/25 s – 1/10000 s |
Shutter speeds longer than the frame duration are ignored (e.g., 1/30 s at 60 fps has no effect). To capture more light, you can lower the frame rate—but beware of increased motion blur.
Choosing the Right Shutter Speed
- No-effect zone: any shutter slower than the frame duration adds no benefit.
- Freeze motion: use shutter ≤ half the frame time (e.g. 1/120 s at 60 fps) to minimise blur, at the expense of exposure.
- Maximise light: use shutter ≈ full frame time (e.g. 1/50 s at 50 fps) to gather maximum exposure, accepting motion blur.
- Intermediate speeds: trade off blur vs brightness by selecting between the 180° rule and the full frame duration.
Best Practices
- For low-light, use the slowest valid shutter, but verify acceptable motion blur.
- For fast action, choose a faster shutter (e.g. ≤ 1/250 s) and supplement with lighting rather than gain.
- Always test in your environment and adjust shutter within the valid range for your chosen framerate.
