For Film Professionals
ShutterFinder detects light flicker instantly and tells you the exact shutter speed to eliminate it. Point, measure, done.
The problem
LED panels, fluorescent tubes, HMI lights, monitors — they all flicker at frequencies invisible to the eye but devastating on camera. Wrong shutter speed means banding, rolling bars, and unusable footage. You only find out in post.
The ShutterFinder way
Point your iPhone at any light source and tap MEASURE. ShutterFinder uses 240fps high-speed capture and real-time FFT analysis to detect the exact flicker frequency. Within seconds, you know the optimal shutter speed.
Precision
Real-time Fast Fourier Transform analysis via Apple's Accelerate framework. Sub-Hz frequency accuracy with parabolic interpolation. Detection range: 40–500 Hz.
Flexibility
Supports all common shooting frame rates: 23.98, 24, 25, 29.97, 30, 50, 60 fps — plus custom input. Switch between shutter speed (1/50) and shutter angle (180°) with one tap.
Intelligence
Automatically identifies the source type — 50Hz mains, 60Hz mains, PWM LED, and more. Change your shooting frame rate after measurement and see the recommendation update instantly.
Fluorescent tube detected
LED panel with PWM dimming
HMI par light
How it works
No complicated menus or settings. Three seconds to flicker-free footage.
Aim your iPhone at any flickering light source — LED panels, fluorescent tubes, HMI lights, monitors, practicals.
Tap MEASURE. The app uses 240fps slow-motion capture for high-resolution temporal sampling with automatic exposure adjustment.
Get the optimal shutter speed instantly. The app automatically stops measuring when it has a confident reading.
Technical Details
Download ShutterFinder and eliminate flicker from your shoots — before you roll.
Download on App StoreRequires iPhone XS or later with iOS 17.0+