IR LED 850nm vs 940nm: How to Choose? Wavelength Selection Guide for Night Vision & Sensing
Conclusion First
The core difference between 850nm and 940nm IR LEDs lies in the trade-off between stealth and photoelectric efficiency: for night vision surveillance and distance priority, choose 850nm (higher camera sensitivity, longer illumination distance, but slight red glow); for covert surveillance, human-machine coexistence, sensing and remote control, choose 940nm (virtually no visible red glow, but effective distance is about 70-80% of 850nm at the same power).
850nm vs 940nm Core Parameter Comparison
| Item | 850nm IR LED | 940nm IR LED |
|---|---|---|
| Visible Red Glow | Slight red glow (red dot visible in dark) | Virtually no red glow, good stealth |
| CMOS/CCD Sensitivity | High (camera quantum efficiency ~1.5-2x of 940nm) | Lower (about 50-67% of 850nm) |
| Effective Distance (same power) | Longer (~1.3-1.5x of 940nm) | Shorter (~70-80% of 850nm) |
| Power Consumption (same brightness) | Lower | Higher (~20-30% more) |
| Typical Applications | Night vision cameras, CCTV, license plate recognition | Covert surveillance, IR remote control, proximity sensors |


