For videographers, DPs, cinematographers & gaffers
Colour temperature and flicker detection. Instant, accurate, always in your pocket.
What it does
Colour Temperature
Close Kelvin approximations from 2500K to 9900K. White balance locked to a fixed 5600K reference for consistent, repeatable readings. A useful on-set guide — not a calibrated colorimeter.
Flicker Detection
240fps sampling with FFT analysis. Detects 50Hz and 60Hz mains flicker and harmonics. Flags PWM dimming that defeats conventional measurement.
Banding Risk Calculator
Set your project frame rate and shutter speed. The app tells you instantly whether you'll get banding — and snaps to a safe combination if you won't.
Freeze & Compare
Pause a reading to lock a reference. Adjust frame rate and shutter while the measurement stays frozen — perfect for matching multiple fixtures.
Calibration
Point at a known 5600K reference, take a five-second reading, and the app learns a custom offset specific to your device and conditions. Works alongside the locked reference mode for absolute consistency across a whole shoot.
Flicker analysis
LED and fluorescent lights flicker at mains frequency — 50Hz in the UK, 60Hz in the US. When your shutter speed doesn't align cleanly, you get banding in post.
ColourTemp's FFT engine analyses 256 luminance samples per cycle and snaps detected frequencies to known harmonics. It then calculates the exact exposure relationship for your frame rate and shutter angle — and tells you whether you're safe before you roll.
Why this exists
I'm a DP and director based in Cornwall, working in documentary, interiors, luxury travel and branded content. I spend a lot of time filming in spaces where the lighting is entirely out of my hands — beautiful rooms, working hotels, boats, coastal locations. Practical fixtures that flicker, mixed sources that won't match in post, colour temperatures nobody thought to check on the day.
ColourTemp came out of that frustration. I needed something fast and reliable on set — not a dedicated piece of kit, just my phone. So I built it.
Colour temperature readings are close approximations derived from the iPhone camera sensor and should be treated as a useful on-set guide rather than a substitute for a calibrated colorimeter. Accuracy varies by device, environment, light source and surface. Flicker detection is designed to identify common mains-frequency flicker patterns; results should be verified on camera in critical situations.
iPhone only. No account, no tracking, works offline.