Color Temperature Meter+ vs calibratr

Color Temperature Meter+ measures the colour temperature of the light around you in Kelvin, with tint, mired and the camera white balance to match, straight from your iPhone's camera. ▶ HOW IT MEASURES On iPhone the app reads the camera's own estimate of the light falling on the scene, the same estimate iOS uses to set white balance. Point the camera at a plain white or grey surface lit by the light you want to measure, not at the lamp itself. The reading settles within seconds and shows a ± range, so you can see how steady it is. When that estimate is not available, the app samples the centre of the frame instead, and you can calibrate it once on white paper in daylight. ▶ WHAT YOU SEE • Kelvin with a ± range, updating live • Mired value for filter and gel maths • Light type: golden hour, tungsten, fluorescent, LED, daylight, cloudy, shade • Tint (green or magenta) and Duv • Spectrum bar from 1,000 K to 15,000 K • The nearest camera white-balance preset: tungsten, fluorescent, flash, daylight, cloudy or shade ▶ FREEZE AND SAVE Tap Freeze to hold the current reading. A result card shows the Kelvin, mired, light type and matching white-balance preset, with Save Reading and Measure Again right below it. Saved readings keep their date and time. The latest 50 are kept, you can delete any of them, and you can export the list as CSV. ▶ PHOTOGRAPHY WB ASSIST Pick a target of 3200 K, 4300 K, 5500 K or 6500 K. The app shows the mired shift from the measured light to that target, the Kelvin to dial into your camera's custom white balance, and the CTO or CTB gel strength that closes the gap, from 1/8 upwards. ▶ REFERENCE CHART Thirteen common light sources, from candle flame (1,900 K) to clear blue sky (10,000 K), to compare with what you measured. ▶ HONEST LIMITS A phone camera is not a spectrometer. The app reports correlated colour temperature and tint, which is what matters for matching white balance and choosing gels. It does not measure spectral power distribution, CRI or TLCI, and two lamps with the same colour temperature but different spectra read the same. Mixed lighting gives a blend of the sources. Use it to set up shoots, match bulbs and check rooms; use a dedicated colour meter for critical colour work. ▶ PRIVACY Camera images are analysed on your device and are never uploaded. Available in 30 languages.

Your photos, the way you edited them. Out of the box, a monitor rarely shows what is in the file: too cool, too blue, with greys that drift in the shadows. Anyone who edits photos then corrects faults that are not in the picture at all. calibratr turns your iPhone into a measuring instrument for displays and makes your monitor trustworthy again. Together with the free Mac app it calibrates your monitor. The Mac shows colour patches, the iPhone measures them in RAW: no image processing, no white balance, fixed exposure. The result is an ICC colour profile for exactly that display. White point, grey balance and tone curves are corrected, and the verification patches show in ΔE how well it went. HOW IT WORKS • Open the Mac app and choose “Start calibration” • Scan the QR code on the screen with the iPhone. Both devices on the same Wi‑Fi, everything stays on the local network • Hold the iPhone a hand's width from the centre of the screen and start on the iPhone • One to ten minutes later the result is on the iPhone and the Mac: a before and after picture comparison, plus white point, gamma, contrast, gamut and grey balance WHAT THE APP DOES WITHOUT A MAC The light meter reads any glowing surface, whether monitor, lamp or window, and shows colour temperature, white point, tint, exposure and signal-to-noise. It needs only the iPhone. WHAT IT COSTS Measuring, the report and the picture comparison are free and stay free. The one-time purchase “Keep the result” unlocks installing the finished profile on the Mac: for all your displays, for good. No subscription, no account, no server. WHAT IT CANNOT DO A phone camera is not a spectroradiometer. calibratr measures white point, grey balance and tone curves repeatably; it takes the position of the primaries from the monitor's factory profile. There is no absolute luminance in cd/m². If you need a reference instrument for prepress, you need a colorimeter. REQUIREMENTS • iPhone with a RAW-capable camera, iOS 16 or later • For calibration: the free Mac app (calibratr.app.freshx.de), macOS 13 or later PRIVACY No accounts, no analytics, no advertising. Shots are reduced to readings on the device and are neither stored nor transmitted. iPhone and Mac connect directly over your Wi‑Fi.