KEY TAKEAWAYS
- Flicker is created by light-output modulation
- PstLM addresses visible flicker perception
- SVM addresses stroboscopic effects during motion
- Driver and dimmer compatibility is critical
- Test performance across the real dimming range
01What Causes LED Flicker
LED output responds rapidly to variations in driver current. Poor driver design, incompatible dimming or power-quality issues can create periodic light modulation.
Some flicker is visible, while higher-frequency effects may appear during eye or object movement.
02PstLM and SVM
PstLM is used to describe short-term visible flicker perception. SVM evaluates stroboscopic visibility associated with motion.
Lower values generally indicate reduced risk, but requirements and test conditions should be checked against the relevant market rules and project standard.
Practical Design Checklist
01 PstLM and SVM
PstLM is used to describe short-term visible flicker perception. SVM evaluates stroboscopic visibility associated with motion.
02 Why It Matters
Problematic flicker can cause distraction, visual discomfort and poor video recording. It is especially important in offices, schools, hospitality, retail and spaces with cameras or moving machinery.
03 Drivers and Dimming
Select drivers with documented flicker performance across the full dimming range. Verify compatibility among driver, dimmer, control protocol and luminaire load.
04 Specify and Test
Request measured PstLM and SVM data, confirm the test voltage and dimming condition, and evaluate a sample installation.
03Why It Matters
Problematic flicker can cause distraction, visual discomfort and poor video recording. It is especially important in offices, schools, hospitality, retail and spaces with cameras or moving machinery.
Sensitive occupants may experience effects even when modulation is not obvious.
04Drivers and Dimming
Select drivers with documented flicker performance across the full dimming range. Verify compatibility among driver, dimmer, control protocol and luminaire load.
Minimum dimming level, fade quality and low-end stability should be tested.
Specification Review Matrix
| Design Question | What to Verify | Why It Matters |
|---|---|---|
| Performance | Flicker is created by light-output modulation | SVM addresses stroboscopic effects during motion |
| Application | PstLM addresses visible flicker perception | Driver and dimmer compatibility is critical |
| Maintenance | SVM addresses stroboscopic effects during motion | Test performance across the real dimming range |
05Specify and Test
Request measured PstLM and SVM data, confirm the test voltage and dimming condition, and evaluate a sample installation.
Use professional measurement equipment for critical projects rather than relying on phone-camera banding alone.