LightTemp

LightTemp turns your smartphone into a professional on-set measuring tool. Read the color temperature of any light source in real time - no expensive hardware required.

Built by a filmmaker, for filmmakers.

◆ REAL-TIME KELVIN
Point your camera at a light source and instantly read the Kelvin value. Tap the image to measure that exact spot (double-tap = center).

◆ TINT (GREEN / MAGENTA)
Detect color casts from LED and fluorescent lights on the green-magenta axis.

◆ CALIBRATE TO YOUR DEVICE
Calibrate LightTemp against a known reference value – so the reading matches your camera exactly.

◆ AUTOMATIC LIGHT SOURCE DETECTION
The app recognizes Tungsten, LED, HMI, daylight, candlelight or fluorescent – including a flicker warning.

◆ PRO SCOPES
• Histogram – brightness distribution
• Waveform – luminance across the image width
• RGB Parade – red/green/blue separately for a quick white-balance check

◆ FALSE COLOR & ZEBRA
Exposure overlays like on professional monitors. False Color shows correct skin tones and clipping; Zebra marks overexposed areas with diagonal stripes.

◆ EXPOSURE ASSISTANT
A live tip below the histogram – instantly tells you whether to open up or stop down.

◆ LIGHTING RATIO (KEY:FILL)
Set the reference on the key light, aim the crosshair at the fill – LightTemp shows the brightness ratio in stops.

◆ GEL MATCHING
Compare two light sources – the app recommends the right CTO/CTB gel to match them, plus a camera white-balance compromise.

◆ SHOT MATCH
Save a scene's lighting and reproduce it exactly on the next shooting day.

◆ GOLDEN & BLUE HOUR
Calculates the sun's position from your location with a countdown to the next phase.

◆ MORE TOOLS
• Live camera data: ISO, shutter, aperture, FPS
• Pinch-to-zoom with indicator
• Freeze function to lock the value
• Export log & scenes as PDF
• Kelvin alarm (vibrates at target value)
• Four languages: English, German, French, Spanish

PRIVACY
All data stays on your device. No accounts, no tracking, no ads.

Note: Accuracy depends on your device's camera. Use the calibration for best results. LightTemp is an assistive tool and does not replace a calibrated hardware light meter for the most demanding use.