LumaCadence: Light Flicker

Keep a repeatable record of your indoor lighting. LumaCadence uses your iPhone rear camera to sample about five seconds of brightness variation. Screen indoor lamps for detectable fluctuations and compare the same lamp at different dimming settings. All features are free, with no ads, in-app purchases or account required. SEE THE EVIDENCE Results distinguish detected variation, no significant variation detected in this sample, and an inconclusive measurement. Inspect frame rate, sampling duration, relative modulation depth, exposure, frame loss and scene changes. FOLLOW THE PROCESS See a live brightness waveform while framing a light. The report shows sampling, quality checks and periodic signal analysis, with additional waveform and capture details. Cancel a capture at any time. REVISIT EACH LAMP Save measurements by room, lamp and brightness setting. Compare records for one lamp, reopen full reports, share a summary or export CSV. ON-DEVICE PROCESSING Camera frames are processed locally and are not saved as photos or video. The app does not upload your measurements. You control saving, deletion and sharing. REQUIREMENTS AND LIMITATIONS Requires an iPhone rear camera with a supported high-frame-rate format. 240 fps offers fuller sampling; lower frame rates provide limited screening. Aim at a lampshade or a surface lit by one lamp and keep the phone steady. Avoid direct glare and mixed light sources. Camera sampling cannot reliably cover every flicker frequency. Exposure, dropped frames, rolling shutter and high-frequency PWM aliasing can affect results. A quiet result does not prove that a light is flicker-free. Exact frequency values are not shown before independent calibration. This is not a medical, eye-safety or product certification tool. The current version focuses on indoor lamps and has no dedicated screen measurement mode. Available in English and Simplified Chinese. The app follows your system or per-app language setting.