FlickerHz

Offline Ready
LIGHT SOURCE FREQUENCY
--.-Hz
WAITING FOR CAMERA...
Percent Flicker
--.-%
Flicker Index
-.---
Waveform THD
--.-%
EU Ecodesign (SVM)
-.--
Driver Quality
UNKNOWN
Signal Confidence 0%
No Match

Camera Input Scanner

Auto Exposure AUTO SCANNING
Exposure: Optimal
ROI: Auto Core

Requesting camera permission...

⚠️ Point the crosshair directly at the center of the light bulb.

Signal Diagnostics

Flicker Waveform (Brightness over scanlines)
Fourier Transform (Hz Spectrum)

Analyzer Controls

Profile: Default (30.0ms)
30.0 ms
10ms (Fast) 45ms (Slow)

Session Recorder & Certification

STANDBY

Capture a 10-second audit sample to evaluate driver stability, export raw time-series datasets, or generate an eye safety certificate.

How It Works & Setup Tips

📷 The Physics of Rolling Shutter

Smartphone cameras read out the pixel sensor row-by-row (rolling shutter) rather than all at once. When pointing at a flickering light bulb, different rows are exposed at slightly different times. This translates the temporal oscillation of the light into a spatial pattern of dark and bright bands across the frame. By counting these bands relative to the sensor's readout speed, we calculate the exact frequency (Hz).

⚙️ How to Get High-Precision Readings

  • Increase shutter speed (manual exposure): If exposure is too long, the bands blur out. To force your phone's camera into high shutter speed, point it directly at a bright light bulb. This forces the camera's auto-exposure to use a very fast shutter speed (under 1ms), producing extremely sharp bands.
  • Hold the phone still: Keep the phone steady or lean it against a surface so that hand movement doesn't disrupt the spatial bands.
  • Perform the Auto-Calibration: Every phone's camera sensor has a slightly different row readout speed (rolling shutter skew). Point at a standard non-LED incandescent or fluorescent bulb (which fluctuates at exactly double your AC grid frequency: 100Hz or 120Hz) and press Auto Calibrate to save your phone's exact profile!

Screen Refresh Strobe Generator

Point another phone or test camera at this screen to calibrate its rolling shutter line skew.