IR LED Guide
IR LED 850nm vs 940nm — Which wavelength to choose
The most common decision when choosing a near-infrared LED is 850nm vs 940nm. They differ clearly in visibility, sensor sensitivity, and range. Here's which wavelength fits machine vision, CCTV, and biometric applications.
UV
Visible
IR
SWIR
MWIR
200nm1000nm3000nm5000nm+
COMPARISON
850nm vs 940nm at a glance
| Spec | 850 nm | 940 nm |
|---|---|---|
| Visible red glow | Faint red dot | Near-invisible (covert) |
| Sensor sensitivity | High (high CMOS QE) | Lower (~50%) |
| Night range | Longer | Shorter |
| Sunlight interference | Moderate | Low (atmospheric absorption) |
| Typical use | Outdoor CCTV, long range | Indoor security, iris/face ID |
HOW TO CHOOSE
By application
Outdoor CCTV / long range → 850nm. Higher sensor sensitivity reaches farther and brighter per watt. Accepts a faint red dot.
Indoor security / iris & face ID → 940nm. Near-zero red glow is unobtrusive, and low sunlight interference improves indoor/close-range accuracy.
Machine vision inspection → Depends on target reflectance/transmission. Metals/PCBs favour 850nm; certain plastics/organics may need 940nm or SWIR. For precision inspection, also consider SWIR LED.
DOWA
DOWA IR LED lineup
650nm to 980nm high-power NIR bare dies for machine vision, security, and biometrics.
Tell us your NIR wavelength
Beyond 850/940nm — full 650–980nm range plus Point Source options. We'll match samples and datasheets to your spec.